Comparison and Analysis of Austrian and American

Transcription

Hydromorphological Survey Methods (Case Study
River System Traisen / Lower Austria)
Diploma Thesis
submitted by:
Jochen Steindl
Supervisor:
Ao.Univ.Prof. Dipl.-Ing. Dr.nat.techn. Susanne Muhar
Co-Supervisor:
Philip R. Kaufmann
Master-Thesis submitted in partial fulfilment of the requirements for the degree
of ‘Diplomingenieur’
Vienna, 2012
University for Natural Resources and Life Sciences, Vienna
(Boku - Universität für Bodenkultur, Wien)
Department of Water, Atmosphere and Environment
Institute of Hydrobiology and Aquatic Ecosystem Management
Water is not a commercial product like any other but, rather,
a heritage which must be protected, defended and treated as
such.
Directive 2000/60/EC of the European Parliament and of the Council
You cannot understand life and its mysteries as long as you
try to grasp it. Indeed, you cannot grasp it just as you cannot
walk off with a river in a bucket. If you try to capture running
water in a bucket, it is clear that you do not understand it
and that you will always be disappointed, for in the bucket
the water does not run. To "have" running water you must
let go of it and let it run.
Alan Watts
from “The Wisdom of Insecurity”
Abstract
The European Water Framework Directive was established in December 2000 and demands
from the Member States the achievement of the good ecological status for all natural surface
water bodies which are not heavily modified. For the evaluation of “good status” biological
and physico-chemical quality elements are used. The hydromorphological status is applied
for the assessment of the high ecological status of a water body and plays a crucial role in
the evaluation of the good status as well as with regard to prevent the deterioration of the
ecological status. The European Standard EN 14614 describes a guidance for assessing the
hydromorphological features of rivers and defines the parameters that have to be surveyed,
but it does not present a definite and universal applicable assessment method. Due to the
diverse river types in Europe, it is the responsibility of the Member States to develop and
utilize their own national assessment methods.
The aim of this thesis is the analysis and discussion of hydromorphological assessment
methods that are based on different approaches and evaluation procedures. The main focus
is on the following criteria: Temporal and spatial scale, field survey procedures, surveyed and
assessed parameters, evaluation criteria, comparability and analysis of the results, and
fulfilment of the Water Framework Directive requirements.
For this purpose, an Austrian and an US-American hydromorphological survey method were
analysed and compared. This is the qualitative NÖMORPH method that was developed for
the ecomorphological mapping of selected running waters in Lower Austria. The task of this
method is the description and the hydromorphological evaluation of the condition of water
bodies with the help of visual investigations and assessments of summarizing parameters.
The predominantly quantitative Physical Habitat Characterization method was part of the
Environmental Monitoring and Assessment Program Western Pilot Study, that was executed
in the western USA from 2000 to 2004. This method focuses on measurements and
estimations of predefined attributes along the river channel, the riparian zone, and of the
surroundings. In the course of field surveys, both methods were applied at selected stream
reaches of the Traisen river catchment area in Lower Austria.
The presentation of the thesis includes the data analysis as well as the hydromorphological
status evaluation for single sample reaches. It is illustrated how far the results of the methods
coincide respectively complement one another. Concluding, it is discussed to what extent the
NÖMORPH method and the Physical Habitat Characterization meet the demands of the
European Water Framework Directive.
iv
Abstract
Im Dezember 2000 trat die Europäische Wasserrahmenrichtlinie in Kraft, die von den
Mitgliedstaaten eine Erreichung des guten ökologischen Zustandes für alle natürlichen
Oberflächengewässer, die nicht als erheblich verändert eingestuft werden, fordert. Für die
Bewertung
des
Zustandes
werden
biologische
und
physikalisch-chemische
Qualitätskomponenten verwendet. Der hydromorphologische Zustand wird dabei für die
Bewertung des sehr guten Zustandes eines Wasserkörpers herangezogen und spielt auch
bei der Bewertung des guten Zustandes und in Hinblick auf das Verschlechterungsverbot
des ökologischen Zustandes eine wesentliche Rolle. Die europäische Norm EN 14614
beschreibt eine Anleitung zur Beurteilung hydromorphologischer Eigenschaften von
Fließgewässern und legt die zu erhebenden Kenngrößen fest, stellt aber keine absolute und
universell einsetzbare Aufnahmemethode dar. Aufgrund der vielfältigen Fließgewässertypen
in Europa ist es Aufgabe der Mitgliedstaaten eigene nationale Aufnahmemethoden zu
entwickeln und anzuwenden.
Ziel dieser Diplomarbeit ist die Analyse und die Diskussion von hydromorphologischen
Aufnahmemethoden,
die
auf
unterschiedlichen
Herangehensweisen
und
Auswertungsverfahren basieren. Hauptaugenmerk wird dabei auf folgende Kriterien gelegt:
Zeitliche und räumliche Maßstäbe, Arbeitsablauf der Feldarbeiten, erhobene und bewertete
Parameter, Bewertungskriterien, Vergleichbarkeit und Analyse der Ergebnisse der
Datenauswertung, und die Erfüllung der Anforderungen der Wasserrahmenrichtlinie.
Es wurden eine österreichische und eine US-amerikanische
hydromorphologische
Aufnahmemethode analysiert und einander gegenübergestellt. Hierbei handelt es sich um
die qualitative NÖMORPH - Methode, die für die Strukturkartierung ausgewählter
Fließgewässer in Niederösterreich entwickelt wurde. Aufgabe dieser Methode ist die
Beschreibung und die hydromorphologische Zustandsevaluierung von Fließgewässern mit
Hilfe von visuellen Erhebungen und Bewertungen von Summenparametern. Die hingegen
primär quantitative Physical Habitat Characterization war Teil der Environmental Monitoring
and Assessment Program Western Pilot Study, die von 2000 bis 2004 im Westen der USA
durchgeführt wurde. Schwerpunkt sind Messungen und Schätzungen festgelegter Parameter
im Gewässerbett, im Uferbereich und im Umland von Fließgewässern. Beide Methoden
wurden im Zuge von Feldarbeiten an ausgewählten Fließgewässerstrecken im Einzugsgebiet
der Traisen in Niederösterreich angewendet.
Die
Präsentation
dieser
Arbeit
beinhaltet
die
Datenauswertung
sowie
die
hydromorphologischen Zustandsbewertungen für einzelne Aufnahmestrecken. Im Anschluss
wird erläutert, inwieweit die Resultate und Aussagen der untersuchten Methoden
übereinstimmen beziehungsweise sich gegenseitig ergänzen. Den Abschluss dieser Arbeit
v
bildet eine Erörterung, ob und in welchem Maße die beiden Methoden die Anforderungen der
Europäischen Wasserrahmenrichtlinie erfüllen.
vi
Acknowledgements
First, I have to thank everybody I met during my stay in the U.S.. I felt welcome wherever I
went and was impressed by the kindliness I experienced.
I want to thank Susanne Muhar whose support made the realisation of this thesis possible.
My special thanks go to Phil Kaufmann who is working for the Western Ecology Division. His
invitation to come to Corvallis, the field training and his help in the course of my work for this
thesis were fundamental. He brought me into contact with the crews I joined during their field
surveys in Oregon. I really appreciate Phil’s effort and hospitality.
I have to thank the staff of the Department of Environmental Quality for the chance to
accompany their field survey crews. Special thanks to Lesley Merrick, Colin Kambak, and
Kristin Schaedel for awesome field work days in the Trask River watershed and the John
Day Basin.
I had the luck to execute field surveys with Peter Stitcher for Demeter Design, an
environmental consulting firm, in the Tillamook Forest in Western Oregon. I enjoyed the
adventurous working trips with Peter who is a perfect field survey partner.
Certainly, I cannot thank Peter Stitcher and Jessica Baratta Stitcher enough for putting me
up and making me feel home in Portland.
Additionally, I had the possibility to visit the Coos Watershed Association, a local NGO in
Coos Bay, Oregon. I want to thank Dan Draper and Justin Kirk, who I joined during their
survey on Willanch Creek, for an utmost informative day.
I also have to thank Rebecca Miller for the ride to Coos Bay and for offering me
accommodation as well as for introducing me to the Pacific Ocean. I enjoyed the challenging
search for ancient splash dams.
Last but not least, I want to thank my family for their love and support of any kind, in
particular my parents for teaching me the importance of respect for human beings, nature,
and for oneself.
vii
Hydromorphological Survey Methods (Case Study River System
Traisen / Lower Austria)
Table of Contents
Abstract ...............................................................................................................................iv
Abstract ................................................................................................................................v
Acknowledgements............................................................................................................vii
Figures ...............................................................................................................................xiii
Tables.................................................................................................................................xix
Abbreviations ....................................................................................................................xxi
1
2
Introduction...................................................................................................................1
1.1
Challenges of Assessing the Hydromorphological Condition of Running Waters.....1
1.2
Aim and Structure of the Thesis ..............................................................................4
European Hydromorphological Inventory and Assessment Methods ......................5
2.1
Selection of European Hydromorphological Inventory and Assessment Methods ...5
2.1.1
Methods designed to fulfil the requirements of the Water Framework Directive
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF..12
3
Legal Framework and the Implications on Assessment Methods...........................14
3.1
The European Water Framework Directive ...........................................................14
3.1.1
Purpose.........................................................................................................14
3.1.2
Environmental Objectives..............................................................................15
3.1.3
Measures and Procedures ............................................................................15
3.1.3.1 River Basin Districts ......................................................................................15
3.1.3.2 Characterization of Surface Water Body Types.............................................16
3.1.3.3 Type-specific Reference Conditions for Surface Water Body Types..............18
3.1.3.4 Protected Areas ............................................................................................18
3.1.3.5 Pressures and their Impacts..........................................................................18
3.1.3.6 Surface Water Status ....................................................................................19
3.1.3.7 Monitoring Programmes................................................................................20
3.1.3.8 Classification of Ecological Status and Ecological Potential ..........................20
3.1.3.9 Programmes of Measures .............................................................................21
3.1.3.10 River Basin Management Plans ..................................................................21
3.1.3.11 Commission Report.....................................................................................22
3.2
The Austrian Water Act and the European Water Framework Directive ................23
3.2.1
Regulation on Objectives for Quality Elements according to the WFD...........23
viii
3.2.2
Regulation on Monitoring the Conditions of Water Bodies .............................24
3.2.3
Investigation of the Hydromorphological Status Quo of Austrian Water Bodies
........................................................................................................................24
3.2.4
Manual for Hydromorphological Investigation of the Status of Running Waters
........................................................................................................................25
3.2.4.1 Parameter Groups ........................................................................................27
3.2.4.2 Evaluation of the High Hydromorphological Status........................................29
3.2.4.3 Designation of the Good Hydromorphological Status ....................................30
3.2.5
Identification and Designation of Heavily Modified and Artificial Water Bodies
........................................................................................................................31
3.2.6
Evaluation of Artificial and Heavily Modified Water Bodies - Definition of the
Ecological Potential .......................................................................................32
3.2.6.1 Guidance for the Evaluation of Heavily Modified Water Bodies .....................32
3.2.6.1.1 Methodical Procedure to establish the Maximum and the Good
Ecological Potential ................................................................................33
3.3
Assessment of Surface Waters in the USA ...........................................................34
3.3.1
Wadeable Streams Assessment....................................................................34
3.3.2
The National Rivers and Streams Assessment (NRSA) ................................35
3.3.3
Environmental Monitoring and Assessment Program Western Pilot Study ....35
3.3.3.1 Physical Habitat Stressors ............................................................................36
3.3.3.2 Reference Conditions....................................................................................38
3.3.3.3 Extent of Resource - Sampling Sites.............................................................39
4
Methodology ...............................................................................................................40
4.1
Approach ..............................................................................................................40
4.2
Characterization Survey Methods .........................................................................40
4.2.1
NÖMORPH – Ecomorphological Mapping of Selected Running Waters in
Lower Austria................................................................................................................40
4.2.1.1 Background, Tasks and Aims........................................................................40
4.2.1.2 Characterization............................................................................................41
4.2.1.2.1 Reference Conditions.............................................................................42
4.2.1.2.2 General Characterization of the Assessed Parameters ..........................47
4.2.1.3 Evaluation .....................................................................................................48
4.2.1.4 Used Forms ..................................................................................................49
4.2.2
Physical Habitat Characterization..................................................................50
4.2.2.1 Physical Habitat Components .......................................................................50
4.2.2.2 Procedure of Physical Habitat Characterization ............................................51
4.2.2.2.1 Thalweg Profile ......................................................................................52
ix
4.2.2.2.2 Large Woody Debris Tally ......................................................................53
4.2.2.2.3 Channel and Riparian Characterization ..................................................54
4.2.2.2.4 Assessment of Channel Constraint, Debris Torrents, and Major Floods .62
4.2.2.3 Invasive Riparian Plants................................................................................63
4.2.2.4 Stream Discharge .........................................................................................64
4.2.2.4.1 Velocity-Area Procedure ........................................................................64
4.2.2.4.2 Neutrally Buoyant Object Procedure ......................................................65
4.2.2.4.3 Timed Filling Procedure .........................................................................65
4.2.2.4.4 Direct Determination of Discharge..........................................................65
4.2.2.5 Evaluation .....................................................................................................66
4.2.2.5.1 Habitat Characteristics ...........................................................................66
4.2.2.5.2 Riparian Vegetation Cover and Structure ...............................................69
4.2.2.5.3 Human Disturbances and Influences......................................................70
4.2.2.6 Used Forms ..................................................................................................70
4.3
5
6
Comparison NÖMORPH - Physical Habitat Characterization ................................71
4.3.1
Goals of the Surveys .....................................................................................71
4.3.2
Mapped and Evaluated Criteria and Parameters ...........................................72
4.3.3
Field Work.....................................................................................................73
4.3.4
Evaluation .....................................................................................................73
4.3.5
Illustration and Documentation of the Results................................................75
Study Area ..................................................................................................................76
5.1
Traisen..................................................................................................................76
5.2
Retzbach (Site 1) ..................................................................................................78
5.3
Steinpartztalbach (Site 2)......................................................................................79
5.4
Ramsaubach (Site 3) ............................................................................................81
5.5
Kreisbach (Site 4) .................................................................................................82
Reference Conditions and Results............................................................................84
6.1
Retzbach (Site 1) ..................................................................................................84
6.1.1
Reference Conditions....................................................................................84
6.1.2
Results: NÖMORPH......................................................................................86
6.1.3
Results: Physical Habitat Characterization ....................................................88
6.1.3.1
Reach 1/1 ..............................................................................................91
6.1.3.1.2 Summarizing Presentation of Conclusions and Results ........................95
6.1.3.2
Reach 1/2 ..............................................................................................96
6.1.3.2.1 Summarizing Presentation of Conclusions and Results ......................100
6.1.3.3
Reach 1/3 ............................................................................................101
x
6.1.3.4
Reach 1/4 ............................................................................................106
6.2
Steinpartztalbach (Site 2)....................................................................................111
6.2.1
Reference Conditions..................................................................................111
6.2.2
Results: NÖMORPH....................................................................................112
6.2.3
Results: Physical Habitat Characterization ..................................................114
6.2.3.1
Reach 2/1 ............................................................................................117
6.2.3.2
Reach 2/2 ............................................................................................122
6.2.3.3
Reach 2/3 ............................................................................................127
6.2.3.4
Reach 2/4 ............................................................................................132
6.3
Ramsaubach (Site 3) ..........................................................................................137
6.3.1
6.3.2
Results: NÖMORPH....................................................................................137
6.3.3
6.3.3.1
Reach 3/1 ............................................................................................143
6.3.3.2
Reach 3/2 ............................................................................................148
6.3.3.3
Reach 3/3 ............................................................................................153
6.3.3.4
Reach 3/4 ............................................................................................158
6.4
Kreisbach (Site 4) ...............................................................................................163
6.4.1
6.4.2
Results: NÖMORPH....................................................................................164
6.4.3
6.4.3.1
Reach 4/1 ............................................................................................169
6.4.3.2
Reach 4/2 ............................................................................................174
6.4.3.3
Reach 4/3 ............................................................................................179
6.4.3.4
Reach 4/4 ............................................................................................184
xi
7
Discussion ................................................................................................................189
7.1 Analysis of Correspondences and Differences between the NÖMORPH method and
the Physical Habitat Characterization......................................................................189
7.2 Conclusion..............................................................................................................195
Bibliography .....................................................................................................................197
APPENDIX.............................................................................................................................1
APPENDIX A.
Water Framework Directive.....................................................................1
APPENDIX B.
Assessed Parameters of the NÖMORPH method and the Physical
Habitat Characterization.........................................................................9
B.1
NÖMORPH ........................................................................................................ 9
B.1.1
Channel Geometry and Flowability ............................................................. 9
B.1.2
Riverbed....................................................................................................10
B.1.3 Connectivity Water - Land ...............................................................................11
B.1.4
Banks / Riparian Zone ...............................................................................11
B.1.5
Vegetation Surroundings ...........................................................................12
B.2
Physical Habitat Characterization......................................................................13
B.2.1
Channel/Riparian Cross-Section ...............................................................13
B.2.2
Thalweg Profile..........................................................................................14
B.2.3
Riparian "Legacy" Trees and Invasive Alien Plants....................................14
B.2.4
Slope and Bearing.....................................................................................14
B.2.5
Stream Discharge......................................................................................15
B.2.6
Channel Constraint....................................................................................15
B.2.7
Torrent Evidence Assessment...................................................................15
APPENDIX C.
Forms NÖMORPH and Western Pilot Study .........................................17
APPENDIX D.
Field Work Equipment...........................................................................29
xii
Figures
Figure 1: Examples for structures interrupting the river continuum. ......................................42
Figure 2: The River Type Regions of Lower Austria. ............................................................44
Figure 3: Example map “Josephinische Landesaufnahme”: Danube river between Dobrohost
and Bodiky downstream of Bratislava (1783-1784). ......................................................44
Figure 4: Morphological River Types. ...................................................................................45
Figure 5: Valley Forms. ........................................................................................................47
Figure 6: Support reach layout for physical habitat measurements (plan view).....................53
Figure 7: Large Woody Debris influence zones. ...................................................................54
Figure 8: Substrate sampling cross-section. .........................................................................55
Figure 9: Determining bank angle under different types of bank conditions. .........................55
Figure 10: Determining bankfull and incision heights for (A) deeply incised channels, and (B)
streams in deep V-shaped valleys. ...............................................................................56
Figure 11: Schematic showing relationship between bankfull channel and incision. .............57
Figure 12: Example of a Spherical Densiometer...................................................................57
Figure 13: Schematic of modified convex spherical canopy densiometer. ............................58
Figure 14: Riparian zone and instream fish cover plots for a stream cross-section transect. 59
Figure 15: Water surface slope and bearing measurements.................................................61
Figure 16: Riparian and instream fish cover plots for streams with minor and major side
channels. ......................................................................................................................62
Figure 17: Layout of a channel cross-section for obtaining discharge data by the velocityarea procedure. ............................................................................................................64
Figure 18: Sketch of a cross-section.....................................................................................67
Figure 19: Map of Austria. Location of the Traisen catchment area in Lower Austria............77
Figure 20: Catchment of the Traisen and its tributaries upstream of St.Pölten......................77
Figure 21: Location of Site 1, Retzbach................................................................................78
Figure 22: Location of the sample reaches of Site 1. ............................................................79
Figure 23: Location of Site 2, Steinpartztalbach ...................................................................80
Figure 24: Location of the sample reaches of Site 2. ............................................................80
Figure 25: Location of Site 3, Ramsaubach ..........................................................................81
Figure 26: Location of the sample reaches of Site 3 .............................................................82
Figure 27: Location of Site 4, Kreisbach ...............................................................................83
Figure 28: Location of the sample reaches of Site 4 .............................................................83
Figure 29: NÖMORPH evaluation of Site 1, Retzbach..........................................................87
Figure 30: Large Woody Debris all/part in bankfull channel. .................................................89
Figure 31: Large Woody Debris above bankfull channel.......................................................89
xiii
Figure 32: Niederbach, reach 1/1. ........................................................................................91
Figure 33: Impoundment of the Retzbach river.....................................................................91
Figure 34: Reach 1/1 - Habitat classes and substrate classes..............................................91
Figure 35: Reach 1/1 - Fish cover. .......................................................................................92
Figure 36: Reach 1/1 - Riparian vegetation cover - left bank. ...............................................92
Figure 37: Reach 1/1 - Riparian vegetation cover - right bank. .............................................93
Figure 38: Reach 1/1 - Human disturbances and influences - left bank. ...............................94
Figure 39: Reach 1/1 - Human disturbances and influences - right bank. .............................94
Figure 40: Retzbach, reach 1/2. ...........................................................................................96
Figure 41: Retzbach, reach 1/2. ...........................................................................................96
Figure 42: Reach 1/2 - Habitat classes and substrate classes..............................................96
Figure 43: Reach 1/2 - Fish cover. .......................................................................................97
Figure 44: Reach 1/2 left bank - Riparian vegetation cover. .................................................97
Figure 45: Reach 1/2 right bank - Riparian vegetation cover. ...............................................98
Figure 46: Reach 1/2 left bank - Human disturbances and influences. .................................99
Figure 47: Reach 1/2 right bank - Human disturbances and influences. ...............................99
Figure 48: Retzbach, reach 1/3. .........................................................................................101
Figure 50: Reach 1/3 - Habitat classes and substrate classes............................................101
Figure 51: Reach 1/3 - Fish cover. .....................................................................................102
Figure 52: Reach 1/3 left bank - Riparian vegetation cover. ...............................................102
Figure 53: Reach 1/3 right bank - Riparian vegetation cover. .............................................103
Figure 54: Reach 1/3 left bank - Human disturbances and influences. ...............................104
Figure 55: Reach 1/3 right bank - Human disturbances and influences. .............................104
Figure 64: NÖMORPH evaluation of Site 2, Steinpartztalbach. ..........................................113
Figure 65: Large Woody Debris all/part in bankfull channel. ...............................................115
Figure 66: Large Woody Debris above bankfull channel.....................................................116
Figure 67: Steinpartztalbach, reach 2/1 ..............................................................................117
Figure 68: Steinpartztalbach, reach 2/1 ..............................................................................117
xiv
Figure 70: Reach 2/1 - Fish cover ......................................................................................118
Figure 75: Steinpartztalbach, reach 2/2. .............................................................................122
Figure 99: NÖMORPH evaluation of Site 3, Ramsaubach..................................................138
Figure 100: Large Woody Debris all/part in bankfull channel. .............................................140
Figure 101: Large Woody Debris above bankfull channel...................................................141
Figure 102: Ramsaubach: Alien plant species Fallopia japonica. .......................................142
Figure 103: Ramsaubach, reach 3/1...................................................................................143
Figure 105: Reach 3/1 - Habitat classes and substrate classes..........................................143
xv
Figure 106: Reach 3/1 - Fish cover.....................................................................................144
Figure 107: Reach 3/1 left bank - Riparian vegetation cover. .............................................144
Figure 108: Reach 3/1 right bank - Riparian vegetation cover. ...........................................145
Figure 109: Reach 3/1 left bank - Human disturbances and influences. .............................146
Figure 110: Reach 3/1 right bank - Human disturbances and influences. ...........................146
Figure 113: Reach 3/2 - Habitat classes.............................................................................148
Figure 134: NÖMORPH evaluation of Site 4, Kreisbach. ....................................................165
Figure 135: Large Woody Debris all/part in bankfull channel. .............................................167
Figure 136: Large Woody Debris above bankfull channel...................................................167
Figure 137: Münichwaldgraben, reach 4/1..........................................................................169
Figure 138: Münichwaldgraben, reach 4/1..........................................................................169
xvi
Figure 145: Kreisbach, reach 4/2........................................................................................174
Appendix
Figure C-1: NÖMORPH; Main Form Part 1............................................................................17
Figure C-2: NÖMORPH; Main Form Part 2...........................................................................18
Figure C-3: NÖMORPH; Additional Form 1: Structures interrupting the River Continuum
(river name, serial number, ID structure, kind of structure, fish ladder, width, height,
comments)....................................................................................................................19
Figure C-4: NÖMORPH; Additional Form 2: Backwaters. .....................................................20
Figure C-5: EMAP – Western Pilot Study; Channel-Riparian Cross-Section Form: Substrate
Cross-Sectional Information, Bank Measurements, Canopy Cover Measurements, Fish
Cover, Riparian Vegetation Cover, Human Influence Estimates. ..................................21
xvii
Figure C-6: EMAP – Western Pilot Study; Thalweg Profile and Woody Debris Form: Thalweg
Profile, Large Woody Debris. ........................................................................................22
Figure C-7: EMAP – Western Pilot Study; Riparian "Legacy" Trees and Invasive Alien Plants
Form 1: Largest potential Legacy Tree visible, Alien Plant Species. .............................23
Figure C-8: EMAP – Western Pilot Study; Riparian "Legacy" Trees and Invasive Alien Plants
Form 2: Largest Potential Legacy Tree visible, Alien Plant Species..............................24
Figure C-9: EMAP – Western Pilot Study; Slope and Bearing Form: Slope, Bearing,
Proportion (main measurement, first supplemental measurement, second supplemental
measurement). .............................................................................................................25
Figure C-10: EMAP – Western Pilot Study; Stream Discharge Form: Velocity-Area
Procedure, Neutrally Buoyant Object Procedure, Timed Filling Procedure, Direct
Determination of Discharge. .........................................................................................26
Figure C-11: EMAP – Western Pilot Study; Channel Constraint and Field Chemistry: Channel
Pattern, Channel Constraint, Constraining Features, Contact with Constraining Feature,
Bankfull Width, Valley Width. ........................................................................................27
Figure C-12: EMAP – Western Pilot Study; Torrent Evidence Assessment Form: Evidence of
Torrent Scouring, Evidence of Torrent Deposits. ..........................................................28
xviii
Tables
Table 1: Strukturökologische Methode zur Bestandsaufnahme und Bewertung von
Fließgewässern. ............................................................................................................ 5
Table 2: Ökomorphologische Gewässerbewertung in Oberösterreich. .................................. 6
Table 3: Typenspezifische ökomorphologische Bewertungsmethode. ................................... 6
Table 4: Strukturkartierung ausgewählter Fließgewässer Niederösterreichs - NÖMORPH. ... 7
Table 5: Evaluierung flussbaulich-ökologischer Maßnahmen an Lech und Zubringern. ......... 7
Table 6: LAWA-Field Survey. ................................................................................................ 8
Table 7: EcoRivHabitat.......................................................................................................... 9
Table 8: SERCON (System for Evaluating Rivers for Conservation)...................................... 9
Table 9: River Habitat Survey (RHS). ...................................................................................10
Table 10: SEQ-Physique: System for the Evaluation of the physical Quality of watercourses.
.....................................................................................................................................11
Table 11: Physical Habitat Characterization. ........................................................................11
Table 12: SYRAH-CE (Système relationnel d’audit de l’hydromorphologie des cours d’eau.12
Table 13: Guidebook for the evaluation of stream morphological conditions by the
Morphological Quality Index (IQM)................................................................................13
Table 14: Ecoregions and Surface Water Body Types: Rivers - System A. ..........................16
Table 15: Ecoregions and Surface Water Body Types: Rivers - System B. ..........................17
Table 16: Quality elements for the classification of the ecological status of rivers.................19
Table 17: Classification of ecological status and corresponding colour codes. .....................20
Table 18: Classification of ecological potential and corresponding colour codes. .................21
Table 19: Assessment categories, features, and attributes comprising a standard
hydromorphological assessment...................................................................................25
Table 20: Scheme for the evaluation of the high hydromorphological status according to the
“Qualitätszielverordnung” (stretch 500m). .....................................................................29
Table 21: Scheme for the evaluation of the good hydromorphological status according to the
“Qualitätszielverordnung” (stretch 500m). .....................................................................30
Table 22: Biological Definition of the maximum, good, moderate, poor, and bad ecological
potential........................................................................................................................32
Table 23: Example for the evaluation of a summarizing parameter. .....................................48
Table 24: Transformation scheme - NÖMORPH classification (7 classes) to the classification
of the WFD (5 classes). ................................................................................................49
Table 25: Results of the evaluation of the 5 summarizing parameters - Site 1......................86
Table 26: NÖMORPH - Results of the total evaluation for Site 1. .........................................86
Table 27: Results of the physical habitat measurements respectively estimations for Site 1.88
xix
Table 28: Largest visible potential “Legacy” Tree and Alien Plant Species. ..........................90
Table 29: Results of the evaluation of the 5 summarizing parameters - Site 2....................112
Table 30: NÖMORPH - Results of the total evaluation for Site 2. .......................................113
Table 31: Results of the Physical Habitat Measurements respectively Estimations for Site 2.
...................................................................................................................................114
Table 32: Largest visible potential Legacy Tree and Alien Plant Species. ..........................116
Table 33: Results of the evaluation of the 5 summarizing parameters -Site 3.....................137
Table 35: Results of the physical habitat measurements respectively estimations for Site 3.
...................................................................................................................................139
Table 37: Results of the evaluation of the 5 summarizing parameters - Site 4....................164
Table 39: Results of the Physical Habitat Measurements respectively Estimations for Site 4.
...................................................................................................................................166
Table 41: Results of the evaluation of the 5 summarizing parameters - Reach 1/1, right bank.
...................................................................................................................................190
Table 42: Results of the evaluation of the 5 summarizing parameters - Reach 4/4, left bank.
...................................................................................................................................192
Appendix
Table A-1: Biological quality elements. .................................................................................. 2
Table A-2: Hydromorphological quality elements................................................................... 3
Table A-3: Physico-chemical quality elements....................................................................... 4
Table A-4: Definitions for maximum, good and moderate ecological potential for heavily
modified or artificial waterbodies.................................................................................... 5
Table B-5: Natural Choriotopes - Abiotic ..............................................................................10
Table B-6: Natural Choriotopes - Biotic ................................................................................10
Table B-7: Vegetation Types and Cover Classes .................................................................13
Table B-8: Substrate Size Class Codes................................................................................15
Table B-9: Channel Unit Habitat Classes .............................................................................16
Table B-10: Pool Form Codes ..............................................................................................16
xx
Abbreviations
AWB
Artificial Water Body
CEN
Comité
Européen
de
Normalisation
(European
Committee
for
Standardization)
CIS
Common Implementation Strategy
CV
Coefficient of Variability
CWA
Clean Water Act
DBH
Diameter at Breast Height
EMAP
Environmental Monitoring and Assessment Program
FWP
Framework Programme
GEP
Good Ecological Potential
GES
Good Ecological Status
GIG
Geographical Intercalibration Group
HMWB
Heavily Modified Water Body
ldll
large diameter-large length
ldml
large diameter-medium length
ldsl
large diameter-small length
LWD
Large Woody Debris
mdll
medium diameter-large length
mdml
medium diameter-medium length
mdsl
medium diameter-small length
MEP
Maximum Ecological Potential
NGP
Nationaler
Gewässerbewirtschaftungsplan
(National
Water
Body
Management Plan)
NRSA
National Rivers and Streams Assessment
ORD
Office of Research and Development
QTHP
Qualitative Physical Habitat Index
QZVO
Qualitätszielverordnung
RBD
River Basin District
RBMP
River Basin Management Plan
REFORM
Restoring Rivers for Effective Catchment Management
R-EMAP
Regional Environmental Monitoring and Assessment Program
RHS
River Habitat Survey
sdll
small diameter-large length
sdml
small diameter-medium length
sdsl
small diameter-small length
xxi
(US) EPA
(US) Environmental Protection Agency
USGS
U.S. Geological Survey
WFD
Water Framework Directive
xdll
extra large diameter-large length
xdml
extra large diameter-medium length
xdsl
extra large diameter-small length
xxii
1
Introduction
1 Introduction
“Running waters are crossing landscapes like pulsating veins fulfilling their task within the
water cycle of the earth. Together with their surroundings they form manifold habitats for an
extremely speciose and in parts very specific fauna and flora. Floodplains and wetlands act
like huge sponges retaining and cleaning water, augmenting ground water, and thus reduce
the danger of floods. In addition, rivers provide space for recreation and adventures as well
as the basis for many economic activities” (translated from Egger et al. 2009).
“Gradually, the riverine landscape becomes a more limited resource with the development of
settlements, industries, transport, agriculture, and leisure time activities. The numerous
requirements and the exploitation lead to massive encroachments into the ecosystems of
streams and floodplains. Flood protection, land reclamation, power generation, sewage
disposal, and the construction of transportation infrastructure permanently modified river
landscapes and caused heavy alterations of water body systems. Over the last years, special
attention was paid to the conservation respectively the restoration of natural and near-natural
running waters to counteract this development” (translated from Egger et al. 2009). In
Europe, the preliminary highlight of the ongoing efforts to protect running waters is the
“European Water Framework Directive that establishes a legal framework to protect and
restore clean water across Europe and ensure its long-term and sustainable use” (Water
Information System for Europe 2008).
1.1 Challenges of Assessing the Hydromorphological Condition of
Running Waters
“In December 2000, the European Water Framework Directive (WFD) became the
fundamental basis for any water policy-related action by the European Community. Until
2015, all unmodified European surface water bodies shall attain, or maintain the ‘‘good
status’’, defined by a good ecological and chemical status.
Within this framework, hydromorphology is used as a quality component to:
(a) elaborate the type-specific reference conditions of water bodies (Annex II, 1.3 WFD),
(b) define the quality targets for the ecological status assessment,
(c) pre-classify the different types of water bodies (natural, heavily modified or artificial)
(Annex II, 1.1 WFD) and
(d) assess them in terms of current status achievement or failure, and risk (Annex II, 1.4 and
1.5 WFD).
In respect to methodology, WFD guidance is limited. Both ecological status and river habitat
evaluation parameters are generally described, since it is problematic to specify and quantify
water body properties in different European regions. The European Standard EN 14614
‘‘Water quality - Guidance standard for assessing the hydromorphological features of rivers’’
(EN 14614, 2004) is based on existing national assessment methods and enables a basic
assessment of the extent of deviation from reference conditions (WFD ‘‘high status’’).
However, the standard does not provide answers on two important questions (1) how to
perform an integrated quality classification of single hydromorphological features (see Table
19 - check-list) and (2) how to classify the quality of individual features” (Weiß et al. 2007).
1
1
Introduction
“To interpret the data collected and assess current ecological condition, chemical, physical,
and biological measurements must be compared to a benchmark or estimate of what one
would expect to find in a natural condition. Setting reasonable expectations for an indicator is
one of the greatest challenges to making an assessment of ecological condition. On the one
hand, a historical perspective can be taken by comparing current conditions to an estimate of
pre-colonial conditions, pre-industrial conditions, or conditions at some other point in history.
Another possibility is to accept that some level of anthropogenic disturbance is expected and
the best of today’s conditions is used as the benchmark against which everything else is
compared” (cf. United States Environmental Protection Agency 2006).
“The general procedure of classification and monitoring is based, according to the WFD
requirements, on evaluating the deviation of present conditions from a given reference state.
The definition of a reference state respectively a target vision for hydromorphology is
problematic, and the scientific community nowadays agrees to renounce considering a
“pristine”, completely undisturbed condition. This is because, besides being extremely
difficult to define, it would be associated with watershed conditions completely different from
the present. Is it therefore more appropriate to refer to the conditions that would exist in the
present watershed conditions, but in the absence of human disturbances along the channel
and adjacent river corridor” (Rinaldi et al. 2011)?
Muhar et al. (2000) describe “the evaluation and identification of largely intact aquatic
habitats” as based on “the conditions that characterized Austria’s rivers and streams prior to
systematic channel regulation measures (end of 19th to mid 20th century) and the
construction of large hydroelectric stations and chains of dams. In contrast to modifications
caused by local flood protection measures, clog drivers, mills, channel adaptation for
navigation etc. before 1800, these systematic impacts led to large-scale alterations of whole
river systems”. The evaluation in the course of the Identification of rivers with high and good
habitat integrity “refered back to a scenario of ‘naturally developed’ Central European cultural
landscapes in which the fundamental functions of most river systems were largely intact and
system-inherent processes could still run their natural course. In Austria, a national land
survey was carried out during the 19th century, providing a high-quality physical reference for
all rivers” (Muhar et al. 2000).
For the management of aquatic ecosystems the development of target visions is essential.
Over the last years it has become customary not only to focus on ecological and hydrological
aspects in the course of the preparation of a target vision but also to include economic and
societal issues which results in an integrative planning process. This means that target
visions are developed by experts and representatives of different fields as well as by citizens
and user groups (cf. Muhar et al. 2003). “The goal of the integration of the obtained target
visions is the harmonization of the targets and (1) the analysis of corresponding and
complementary conclusions and (2) the illustration of possible conflict potential caused by
opposing or alternative objectives” (translated from Muhar et al. 2003).
“While the Member States of the European Union have a great deal of experience in
monitoring the chemical status of their waters, measuring good ecological status brings new
challenges. Given the wide range of ecosystems found across Europe, using one method to
assess all water bodies does not make sense. Instead, the directive established a common
definition of good ecological status, which Member States must use when developing their
national assessment methods. To ensure that national assessment methods to measure
good ecological status deliver comparable results and are consistent with the directive, an
intercalibration exercise is required between Member States with the assistance of European
Commission. The goal of intercalibration is not to establish common assessment systems.
Each Member State chooses its own methods according to the provisions of the directive.
The intercalibration exercise took place between 2003 and 2007 and involved hundreds of
experts across Europe. The European Commission's Joint Research Centre in Ispra, Italy,
coordinated this technical work. Because aquatic ecosystems vary so widely across Europe,
experts set up 14 different Geographical Intercalibration Groups (GIGs) that identified and
2
1
Introduction
then studied thousands of sites in rivers, lakes and coastal and transitional waters across
Europe. The work focuses on defining the upper and lower boundaries of good status. The
line between “good” and “moderate” status is particularly important, as it defines whether or
not a water body will meet the directive's 2015 goal of good status.
The years of intense work have brought a major step forward in protecting European aquatic
ecosystems. But much remains to be done. Member States have agreed to continue the
exercise to fill the gaps of the work achieved to date” (Water Information System for Europe
2008).
A research poject has started on “restoring rivers for effective catchment management”
(REFORM) “funded under 7th FWP (Seventh Framework Programme). REFORM is a 5-year
large scale integrated research project that is targeted towards development of guidance and
tools to make river restoration and mitigation measures more cost-effective and to support
the 2nd and future River Basin Management Plans (RMBPs) for the WFD. Aims of REFORM
are (1) to provide a framework for improving the success of hydromorphological restoration
measures and (2) to assess more effectively the state of rivers, floodplains and connected
groundwater systems. The restoration framework addresses the relevance of dynamic
processes at various spatial and temporal scales, the need for setting end-points, analysis of
risks and benefits, integration with other societal demands (e.g., flood protection and water
supply), and resilience to climate change.
In addition to its impact on the RBMPs, REFORM will provide guidance to other EU
directives (groundwater, floods, energy from renewable resources, habitats) to integrate their
objectives into conservation and restoration of rivers as sustainable ecosystems”
(http://www.cordis.europa.eu 2012).
3
1.2
Aim and Structure of the Thesis
1.2 Aim and Structure of the Thesis
The objective of this thesis is the comparison and analysis of hydromorphological survey
methods to highlight correspondences and differences between them. For this purpose, the
qualitative Austrian NÖMORPH method (see 4.2.1 NÖMORPH – Ecomorphological Mapping
of Selected Running Waters in Lower Austria) and the mainly quantitative American Physical
Habitat Characterization (see 4.2.2 Physical Habitat Characterization), that have different
approaches concerning field survey and data evaluation, have been studied and executed at
selected sites of the Traisen river catchment area in Lower Austria.
First, a selection of hydromorphological inventory and assessment methods is presented with
the help of a short characterization of important criteria, including methods that have been
designed to fulfil the requirements of the European Water Framework Directive.
As the Water Framework Directive is a complex guide line, a section describes the main
rules and procedures to get an insight. Furthermore, the implementation of the directive in
Austria is illustrated. An additional chapter provides information on the assessment of
running waters in the USA.
Subsequently, the procedures as well as the assessed parameters of the NÖMORPH
method and the Physical Habitat Characterization are described. Based on this description
the methods are compared with regard to:
-
Goals of the surveys
Mapped and evaluated criteria and parameters
Temporal and spatial scale
Mapped and assessed parameters
Field survey procedures
Evaluation criteria
To be able to analyze and compare results and conclusions, both methods were applied in
the field at the same pre-defined sample reaches. The survey sites are characterized with
the help of basic data, verbal description, and maps respectively orthophotos.
The sampled reaches were evaluated using reference conditions which were derived from
the river type region and the morphological river type. The reference conditions are pictured
together with the results of the data evaluation for both methods with graphs, tables,
orthophotos, and verbal description including a summarizing presentation of conclusions and
results for every reach.
The final discussion highlights correspondences and differences between the NÖMORPH
method and the Physical Habitat Characterization using selected examples of the results.
Furthermore, potential interrelations between the analyzed methods and the European Water
Framework Directive are questioned.
4
2
European Hydromorphological Inventory and Assessment Methods
2
European
Hydromorphological
Assessment Methods
Inventory
and
“Several methods have been developed in many countries that are based on a census of
physical habitats and diversity of fluvial forms. The approaches used up to now in most
European countries tend to reflect “River Habitat Survey” procedures which are suitable for
defining the presence and diversity of physical habitats but which have not been developed
to comply with the WFD requirements. Therefore, there is an increasing need for an
approach based on the consideration and understanding of the geomorphological processes
responsible for river functioning which can be used not only for a classification but also for
supporting analyses of any interventions and impacts, and the design of mitigation
measures” (Rinaldi et al. 2011).
2.1
Selection of European Hydromorphological Inventory and
Assessment Methods
Several European hydromorphological survey methods are presented to illustrate the
diversity of existing methods as well as the variety of their approaches and procedures. The
main criteria for the selection of the shortly characterized methods was the relevance of a
method concerning the assessment of running waters in a country (amongst others, that the
customers were public agencies). Furthermore, in the course of the literature study it became
apparent which are the most established inventory methods in Austria and in the European
Union:
Austria
Table 1: Strukturökologische Methode zur Bestandsaufnahme und Bewertung von
Fließgewässern.
(translated from Muhar et al. 1993)
Title
Authors
Customer
Thematic emphases
Brief characterization
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Illustration of results
Field of application
Strukturökologische Methode zur Bestandsaufnahme und
Bewertung von Fließgewässern
Spiegler, A., Imhof, G., Pelikan, B., Katzmann, M., et al. (1989)
Federal Ministry of Agriculture and Forestry
Morphology (river bed, current, riparian structures,...)
Riparian vegetation
Structures of surroundings
Utility analysis taking into account different river types
Valley type, hydrology, flow dynamics/behaviour, channel
geometry, longitudinal profile, cross section, substrate, riparian
vegetation, riparian acclivities, types of river training structures,
connection to floodplain, vegetation and landuse surroundings
Homogeneous reaches depending on parameters, >100m
River type specific definition of targets ( 3 types)
4 main classes, 3 intermediate classes
Maps, graphs, data entry forms, verbal description, photo
documentation
Basis for ecological orientated measurements; decision support
5
2
Other
for local and regional development planning; description of
ecological relationships for hydraulic engineers; adult education.
Particular utilizations and impacts, illustration of critical evaluation
cases
Table 2: Ökomorphologische Gewässerbewertung in Oberösterreich.
Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Other
Ökomorphologische Gewässerbewertung in Oberösterreich
Werth, W. (1987)
Federal State Government of Upper Austria
Morphology
Botany (structure of riparian vegetation)
Utility analytical approach
Riparian vegetation, vegetation and landuse surroundings,
hydrology, flow behaviour, channel geometry, longitudinal profile,
cross section, substrate, riparian acclivities, types of river training
structures
Homogeneous reaches depending on parameters, <100m
possible
The natural condition respectively the imagined natural condition
4 main classes, 3 intermediate classes (= 7 classes)
Maps (scale 1:50,000), additional descriptive part
Hydraulic engineering projects (flood protection, water body
management,F)
Suggestions of measurements
Table 3: Typenspezifische ökomorphologische Bewertungsmethode.
Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Typenspezifische ökomorphologische Bewertungsmethode
Muhar, S., Muhar, A., Schmutz, S. (1993)
Federal Ministry for the Environment
Identification of near-natural river stretches in Austria
Morphology: river, banks, Vegetation: river, banks, surroundings
Definition of target systems for single river types
Flow conditions, artificial structures/human impacts, channel
morphology, riparian structures, vegetation active channel,
substrate, riparian vegetation, floodplain vegetation, tributaries,
landuse and vegetation surroundings
< 1km not expedient, short heterogeneous reaches are combined
and the dominant character is evaluated ( nevertheless, the
different situations have to be documented)
Reference conditions according to river type for the
characterization of the target system
Not near-natural, near-natural with slight anthropogenic influence,
near-natural with heavy anthropogenic influence
Maps, verbal description with explanation of evaluation
The method was used for the designation of preserved river type
6
2
specific stretches in Austria from 1994-1998 (Muhar et al. 1998);
illustration of the lack of near-natural river landscapes and the
danger for special water body types, Information and
argumentation for protection measurements concerning running
waters.
Table 4: Strukturkartierung
NÖMORPH.
ausgewählter
Fließgewässer
Niederösterreichs
-
(translated from freiland Umweltconsulting 2001)
Working Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Other
NÖMORPH – Strukturkartierung ausgewählter Fließgewässer
Niederösterreichs (see 4.2.1 NÖMORPH – Ecomorphological
Mapping of Selected Running Waters in Lower Austria
(Strukturkartierung
ausgewählter
Fließgewässer
in
Niederösterreich)
freiland Umweltconsulting
Federal Government of Lower Austria
Reference conditions: River type region, morphological river type,
morphology and vegetation river, banks, surroundings
Analysis of the deviation of the current status from the natural
and characteristic status
Channel geometry and flow characteristics, riverbed, connectivity
water - land, banks/acclivities, vegetation
Reach ends when an assessed parameter changes, reaches at
least 100m long
Reference condition based on morphological river type and river
type region
4 main classes, 3 intermediate classes (= 7 classes)
Maps (1:25,000), verbal description, integration of the data into
the Wasserdatenverbund
First report and basis of evaluation of water ecological aspects
during water management projects
Planning principles for projects improving the ecological
functionality, determination of the worthiness of protection of
running waters, documentation of changes, etc.
Table 5: Evaluierung flussbaulich-ökologischer Maßnahmen an Lech und Zubringern.
(translated from Preis et al. 2008)
Working Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Evaluierung flussbaulich-ökologischer Maßnahmen an Lech und
Zubringern
im
Rahmen
des
Life-Natur
Projektes
„Wildflusslandschaft Tiroler Lech“
Preis, S., Muhar, S., Hesse, A., et al (2001-2008)
Federal Government of Tyrol
Evaluation of ecological engineering measurements along the
river Lech
Mapping before and after the implementation of measurements to
assess the effects on aquatic and terrestrial habitats
Water body system elements: main channel, side channels,
oxbows, vegetated and unvegetated sediment banks
Mesohabitats: 6 types (3 classes of water depth combined with 2
7
2
Investigation unit
Reference condition
Evaluation
classes of flow velocity)
Choriotopes: substrate size classes (see Appendix B)
Woody debris, artificial structures active channel
Whole reaches where measurements were implemented
(reaches were divided into areas with homogeneous
characteristics)
Water body type specific general principle using reference status
(high ecological status)
Assessment for the comparison of the status before and after the
implementation of measurements using 5 condition classes
according to the WFD
Maps, graphs, verbal description
River restoration projects
Germany
Table 6: LAWA-Field Survey.
(Weiß et al. 2007)
Title
Development
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Other
LAWA-FS (field survey)
German Working Group on water issues of the Federal States
and the Federal Government
Federal Government, Federal Environment Ministry
Assessment of the current state compared to a reference state
Field survey for small to medium-sized rivers
Channel: geometry, curvature, river course structures, profile
depth, variation of width, substrate (bed-fixing, substrate types),
channel vegetation and organic debris (bottom structures macrophytes, wood), erosion/deposition character (bars, river
course, width variation, erosion due to curvature), migration
barriers;
Banks: vegetation, impairments;
Floodplain: vegetation, land-use; River valley type
width <1m: 50m length, 1-10m: 100m, 5-10m: 200m, >10m: 500m
Reference state = “potential natural state”
7 classes
Maps, tables, verbal description
River restoration projects, implementation of WFD in Germany
Features do not have the same indicative power, some are rated
higher than others; 3 methods: LAWA - Field Survey (1-10m
width and >10m width), LAWA - Overview Survey (follows the
minimum principle)
8
2
Czech Republic
Table 7: EcoRivHabitat.
(Weiß et al. 2007)
Working Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Other
EcoRivHabitat
Matouskova, M. (2003, 2007)
Ministry of the Environment
Assessment of river habitats in open countryside and in urban
areas
Based on field investigation but recommends processing of
available data
Channel: channel character and shape, natural/artificial steps,
profile stability (deepening, width), bed-fixing, substrate types,
bottom structures (macrophytes, diversity of microhabitats),
erosion and accumulation forms, flow character (human
influences);
Banks: impairments, vegetation;
Floodplain: land-use, retention, flood protection;
River valley type, connection to groundwater, surface water
quality, sewage outlets
Catchment <100km²: 100 or 200m; catchment >100km²: 2001000m
Definition of a potential reference status
Score system: 1-5 points
Maps, graphs, verbal description
Ecohydromorphological
monitoring
and
evaluation
of
morphological quality
Riverbank features, riparian belt, and floodplain separately
assessed, but the final assessment is calculated jointly for both
sides.
Great Britain
Table 8: SERCON (System for Evaluating Rivers for Conservation).
(Smith 2009 and Boon et al. 1996)
Working Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
SERCON (System for Evaluating Rivers for Conservation)
Boon, P.J., Wilkinson, J., and Martin, J. (1998); Boon, P.J.,
Holmes, N.T.H., Maitland, P.S., and Fozzard, I.R. (2002)
Scottish Natural Heritage, Countryside Council for Wales, English
Nature
Evaluation of the conservation value of rivers
Attributes are not assessed in isolation - each one (sometimes in
various forms) is used to build up a picture of the river in terms of
accepted conservation (e.g., data on freshwater fish are used for
4 criteria: naturalness, representativeness, rarity, species
richness)
6 attributes: physical diversity, naturalness, representativeness,
rarity, species richness, and ‘special features’ (34 indicators are
used to measure these attributes).
Evaluated Catchment Sections (ECS): 10-30km, uniform physical
9
2
Reference condition
Evaluation
characteristics of geology, slope, size, etc.
Reference data are used for scoring riverine features
Data is converted into a series of scores on a 0-5 scale for each
of the identified attributes. Scores are weighted and combined to
produce separate indices of conservation value (0-100) for the 6
criteria.
Tables, verbal description
Conservation agencies, river managers and others
Table 9: River Habitat Survey (RHS).
(Raven et al. 1998, Scottish Environmental
http://www.environment-agency.gov.uk 2011)
Working Title
Development
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Other
Protection
Agency
2003,
and
River Habitat Survey (RHS)
Environment Agency (1997/2003)
Environment Agency
Characterization and assessment of the physical structure of
rivers and freshwater streams
4 distinct components:
- a standard field survey method;
- a computer database, for entering results from survey sites and
comparing them with information from other sites throughout the
UK and Isle of Man
- a suite of methods for assessing habitat quality
- a system for describing the extent of artificial channel
modification
Valley: shape, valley floor, land-use in the river corridor
Artificial features
Count: pools, riffles, bars
Channel: channel dimensions, substrate, flow type, modifications,
vegetation types, habitat features
Banks: material, modifications, vegetation structure, land-use,
habitat features, bank profile
500m
“Outstanding sites” as reference sites
Rarity as a quality measure (features occurring less than 5% in
reference sites)
Habitat Quality Assessment Score
Habitat Modification Score
Graphs, maps, verbal description
Improve river basin habitats to achieve the good ecological status
(WFD), results are used in the National Ecosystem Assessment
for England; results of interest to river managers, freshwater
ecologists,
fisheries
and
conservation
organizations,
environmental planners etc.
First survey: 1995-1997
Second survey: 2006-2008
10
2
France
Table 10: SEQ-Physique: System for the Evaluation of the physical Quality of
watercourses.
(http://starwp3.eu-star.at 2011)
Working Title
Development
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Other
SEQ-Physique: System for the Evaluation of the physical Quality
of watercourses
Agences de l'Eau (1998)
Ministry of Environment and the Water Agencies
Morphological Degradation
Assessment of the hydromorphological status of floodplain, banks
and channel by weighted scores of about 50 different features.
Map-derived data: slope, geology, valley form, land use
Field data: valley form, hydrological regime, river continuity
(passability), channel dimensions, channel substrates, flow type,
channel features, channel vegetation, man-made channel
modifications, bank material, bank profile, bank features, bank
vegetation, extent of trees, man-made bank modifications, landuse
Variable (functionally homogeneous reaches)
Reference conditions based on expert judgment (each physical
attribute score is weighted according to the river type surveyed)
Index (100 - 0) subdivided into five quality classes
Reports (paper and digital); maps (paper)
The system provides an integrated appraisal of ecological
watercourse quality and additionally evaluates possible effects of
quality on natural functions and uses by man. One goal of the
system is to determine the action required for policy makers.
The SEQ provides a quality evaluation system for watercourses
in three parts: Water SEQ, Physical SEQ, and Biological SEQ;
applied to all stream types
USA
Table 11: Physical Habitat Characterization.
(Peck et al. 2006 and Kaufmann et al. 1999)
Working Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Physical Habitat Characterization (see 4.2.2 Physical Habitat
Characterization)
Basics developed by Kaufmann, P.R., Robison, E.G. (1994,
1998)
U.S. Environmental Protection Agency (USEPA)
Evaluation of physical habitat in wadeable streams
Quantitative assessment method for site classification and trend
interpretation
Stream Size - Channel Dimension
Channel Gradient
Channel Substrate Size and Type
Habitat Complexity and Cover for Aquatic Fauna
Riparian Vegetation Cover and Structure
Anthropogenic Alterations and Disturbances
11
2
Investigation unit
Reference condition
Evaluation
Other
Channel - Riparian Interaction
40 times the low flow wetted width, never less than 150m
Reference sites = least disturbed sites
see 4.2.2.5 Evaluation
Maps, graphs, statistics, verbal description
Combined data analyses (e.g., field-based physical habitat
measurements, water chemistry, temperature, and remote
imagery of basin land use and land cover) to describe additional
habitat attributes and larger scales of physical habitat or human
disturbance.
The Physical Habitat Characterization was part of the
Environmental Monitoring and Assessment program Western
Pilot Study (EMAP-W) that was executed from 2000 to 2004
2.1.1 Methods designed to fulfil the requirements of the Water Framework
Directive
As the Member States of the European Union are obligated to fulfill the requirements of the
Water Framework Directive to achieve the pre-defined objectives (see 3.1
The
European Water Framework Directive), every country has to design river assessment
methods based on the guidelines of the WFD.
Table 12 and Table 13 illustrate examples of hydromorphological inventory methods that
were developed to meet the requirements of the WFD:
France
Table 12: SYRAH-CE (Système relationnel d’audit de l’hydromorphologie des cours
d’eau.
(Chandesris et al. 2009)
Working Title
Development
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
SYRAH-CE (Système relationnel d’audit de l’hydromorphologie
des cours d’eau)
Cemagref (l’Institut de recherche en sciences et technologies
pour l'environnement, 2008)
Ministère de l’Écologie, du Développement durable, des
Transports et du Logement
Types of damage - disturbance of physical functioning and
structures
A multi-scale hierarchical framework assessment ("top down"
approach) of large scale "damage risk": damage to processes
(flow and sediment transport in particular) and structures
(resulting morphology).
Watershed scale analysis: land use and activities (urbanization,
agriculture, transport, energy), engineering works and uses
Reach scale analysis: processes alterations, structures
alterations, habitat alterations
Fourteen types of hydromorphological damage are processed
Large scale assessment and assessment of homogeneous
reaches respectively sub-reaches
Detection of hydro morphological damages of a "non-natural
origin" which can be clearly linked to deterioration of the
"Ecological state".
Indicator values for the identified "features and uses" of each
12
2
Other
analytical unit; delineation of sectors likely to be classified in
"High status" according to the WFD
Maps, georeferenced mapped databases, verbal description
Analysis tool for the hydromorphological functions of water
courses to achieve the objectives set by the European Water
Framework Directive; aid for management decision and functional
restoration.
The primary determinants on a regional scale (relief, climate,
geology) define the hydro morphological control variables
(hydrological and sedimentary regimes, width and gradient of
valley bottoms). The key factors of ecological status are
dependent on these variables, as well as on the structure of the
riparian vegetation and the correct state of the water course's
lateral and vertical connectivity: physical habitat, aquatic
"climate", food webs.
Italy
Table 13: Guidebook for the evaluation of stream morphological conditions by the
Morphological Quality Index (IQM)
(Rinaldi et al. 2009 and http://www.isprambiente.gov.it 2011)
Working Title
Authors
Customer
Thematic emphases
methodology
Mapped/evaluated
criteria/parameters
Investigation unit
Reference condition
Evaluation
Other
Guidebook for the evaluation of stream morphological conditions
by the Morphological Quality Index (IQM)
Rinaldi, M., Surian, N., Comiti, F., Bussettini, M. (2011)
Istituto Superiore per la Protezione e la Ricerca Ambientale
Evaluation of present conditions and future monitoring
Field survey and interpretation
Remote sensing and GIS analyses
Phase 1: General setting and segmentation (physiographic units,
confinement, channel morphologies, other discontinuities)
Phase 2: Evaluation of the current morphological conditions
(vegetation, morphology, continuity, hydrology) - functionality,
artificiality, morphological changes.
Phase 3: Monitoring (current trends, morphological recovery).
Segmentation into relatively homogeneous reaches (up to several
km)
Reference condition identified with: (a) functionality of the
processes, corresponding to dynamic equilibrium conditions; (b)
absence of artificiality; (c) absence of significant adjustments of
form, size and bed elevation in a time interval of the last decades.
Scoring system, result is one of 5 classes (1-5)
Maps, photo documentation, verbal description
The method is designed to fit with the requirements of the WFD,
but it is not exclusive for this scope. It evaluates the
morphological conditions (quality) independently from the
ecological state, it emphasizes processes and trends of channel
adjustments, and it represents an overall morphological
evaluation rather than a simple survey of morphological features.
The method, designed primarily for the hydromorphological
assessment in compliance with the WFD, is part of a wider
methodological framework (IDRAIM: system for stream
hydromorphological assessment, analysis, and monitoring)
13
3.1
The European Water Framework Directive
3
Legal Framework and the Implications on Assessment
Methods
Laws and regulations not only reflect the development of a society, they also have the
function to control and support further development. The new directives of the European
Union significantly influence the national legislation of the Member States, also in the field of
the protection and the sustainable use of natural resources.
3.1 The European Water Framework Directive
In December 2000, the European Water Framework Directive was established that requires
from the Member States the achievement of the good ecological status for all natural surface
water bodies which are not heavily modified. The purpose and the objectives of this directive
are precisely defined as illustrated by the following chapters (shortened and extracted from:
European Commission 2000):
3.1.1 Purpose
Article 1
“The purpose of this Directive is to establish a framework for the protection of inland surface
waters, transitional waters, coastal waters and groundwater which:
(a) prevents further deterioration and protects and enhances the status of aquatic
ecosystems and, with regard to their water needs, terrestrial ecosystems and wetlands
directly depending on the aquatic ecosystems;
(b) promotes sustainable water use based on a long-term protection of available water
resources;
(c) aims at enhanced protection and improvement of the aquatic environment, inter alia,
through specific measures for the progressive reduction of discharges, emissions and losses
of priority substances and the cessation or phasing-out of discharges, emissions and losses
of the priority hazardous substances;
(d) ensures the progressive reduction of pollution of groundwater and prevents its further
pollution, and
(e) contributes to mitigating the effects of floods and droughts
and thereby contributes to:
-
the provision of the sufficient supply of good quality surface water and
groundwater as needed for sustainable, balanced and equitable water use,
-
a significant reduction in pollution of groundwater,
-
the protection of territorial and marine waters, and
14
3.1
-
achieving the objectives of relevant international agreements, including those
which aim to prevent and eliminate pollution of the marine environment, by
Community action under Article 16(3) to cease or phase out discharges,
emissions and losses of priority hazardous substances, with the ultimate aim of
achieving concentrations in the marine environment near background values for
naturally occurring substances and close to zero for man-made synthetic
substances” (European Commission 2000).
3.1.2 Environmental Objectives
The environmental objectives of the Water Framework Directive concerning surface waters,
groundwater, and protected areas are specified in Article 4.
For surface waters the targets are as follows:
•
“The Member States are to implement necessary measures to prevent deterioration
of the status of all bodies of surface water.
•
All bodies of surface water have to be protected, enhanced and restored, subject to
artificial and heavily modified bodies of water (see 3.2.5 Identification and
Designation of Heavily Modified and Artificial Water Bodies), with the aim of achieving
good surface water status at the latest 15 years after the date of entry into force of
the Directive (see also Appendix A).
•
Protection and amelioration of all artificial and heavily modified bodies of water, with
the aim of achieving good ecological potential and good surface water chemical
status at the latest 15 years from the date of entry into force of the Directive (see
also Appendix A).
•
Implementation of the necessary measures with the aim of progressively reducing
pollution from priority substances and ceasing or phasing out emissions, discharges
and losses of priority hazardous substances” (European Commission 2000).
3.1.3 Measures and Procedures
The European Water Framework Directive consists of a complex system of rules concerning
procedures, measures and time limits. The following sections give an overview of the main
points with the focus on rivers and hydromorphology.
3.1.3.1 River Basin Districts
According to the Water Framework Directive Member States have to assign the river
catchments within their national territory to individual river basin districts. ‘River basin district’
is defined as “the area of land and sea, made up of one or more neighbouring river basins
together with their associated groundwaters and coastal waters, which is identified as the
main unit for management of river basins”.
In case of international river basin districts the involved Member States coordinate
appropriate administrative arrangements together. If “a river basin district extends beyond
the territory of the Community, the concerned Member States have to endeavour to establish
an appropriate coordination with the relevant non-Member States, with the aim of achieving
the objectives of the Water Framework Directive throughout the river basin district”.
15
3.1
The Water Framework Directive requires that “each Member State ensures that for each river
basin district or for the portion of an international river basin district falling within its territory:
-
an analysis of its characteristics,
a review of the impacts of human activity on the status of surface waters and on
groundwater, and
an economic analysis of water use is undertaken and that it is completed at the
latest four years after the date of entry into force of the Directive.
These analyses and reports have to be reviewed, and if necessary updated at the latest 13
years after the date of entry into force of the Water Framework Directive and every six years
thereafter” (European Commission 2000).
3.1.3.2 Characterization of Surface Water Body Types
After the identification of the location and boundaries of bodies of surface water, the Member
States have to carry out a first characterization of all these water bodies using the following
methodology (cf. European Commission 2000):
1. “The surface water bodies within a river basin district are assigned to one of the surface
water categories:
-
rivers, lakes, transitional waters or coastal waters
or artificial surface water bodies or heavily modified surface water bodies.
2. For each surface water category, the relevant surface water bodies within the river basin
district are differentiated according to types that are defined using either “system A” or
“system B“ ( see Table 14 and Table 15).
3. System A: First, the surface water bodies within the river basin district are allotted to the
relevant ecoregions. Then the water bodies within each ecoregion are differentiated by
surface water body types with the help of the descriptors listed in the tables for system A.
4. If system B is used, Member States must achieve at least the same degree of
differentiation as would be achieved using system A. The surface water bodies within the
river basin district are differentiated into types using the values for the obligatory descriptors
and such optional descriptors, or combinations of descriptors, as are required to ensure that
type specific biological reference conditions can be reliably derived.
5. For artificial and heavily modified surface water bodies the differentiation is undertaken in
accordance with the descriptors for whichever of the surface water categories most closely
resembles the heavily modified or artificial water body concerned.
6. Member States have to submit to the Commission a map or maps (in a GIS format) of the
geographical location of the types consistent with the degree of differentiation required under
system A” (European Commission 2000).
16
3.1
Table 14: Ecoregions and Surface Water Body Types: Rivers - System A.
(European Commission 2000)
Fixed typology
Descriptors
Ecoregion
Ecoregions shown on map A in Annex XI of
the Water Framework Directive
Type
Altitude typology
high: >800 m
mid-altitude: 200 to 800 m
lowland: <200 m
Size typology based on catchment area
small: 10 to 100 km2
medium: >100 to 1 000 km2
large: >1 000 to 10 000 km2
very large: >10 000 km2
Geology: calcareous, siliceous, organic
Table 15: Ecoregions and Surface Water Body Types: Rivers - System B.
Alternative characterisation
Physical and chemical factors that
determine the characteristics of the river
or part of the river and hence the
biological population structure and
composition
Obligatory factors
altitude
latitude
longitude
geology
size
distance from river source
energy of flow (function of flow and slope)
mean water width
mean water depth
mean water slope
form and shape of main river bed
river discharge (flow) category
valley shape
transport of solids
acid neutralising capacity
mean substratum composition
chloride
air temperature range
mean air temperature
precipitation
Optional factors
17
3.1
3.1.3.3 Type-specific Reference Conditions for Surface Water Body Types
“For each characterized surface water body type (see 3.1.3.2 Characterization of Surface
Water Body Types) type-specific hydromorphological and physicochemical conditions have
to be established representing the values of the hydromorphological and physicochemical
quality elements for that surface water body type at high ecological status (see Appendix A).
Furthermore, type-specific biological reference conditions are determined that illustrate the
values of the biological quality elements for that surface water body type at high ecological
status (see Appendix A).
If the procedures set out in this section are applied to heavily modified or artificial surface
water bodies they do not refer to the high ecological status but to the maximum ecological
potential (see Appendix A). The values for the maximum ecological potential for a water body
have to be reviewed every six years.
Type-specific reference conditions can either be spatially based or based on modelling, or
are derived using a combination of these methods. Where it is not possible to use these
methods, Member States can call on expert judgements to establish such conditions.
Where reliable type-specific reference conditions for a quality element in a surface water
body type cannot be established due to high degrees of natural variability in that element, not
just as a result of seasonal variations, it is possible to exclude that element from the
assessment of ecological status for that surface water type. In such circumstances Member
States have to state the reasons for this exclusion in the river basin management plan”
(European Commission 2000).
3.1.3.4 Protected Areas
“The Member States have to register all areas located within each river basin district which
are requiring special protection under specific Community legislation for the protection of the
surface water and groundwater or for the conservation of habitats and species directly
depending on water within four years after the date of entry into force of the Directive” (see
Appendix A, European Commission 2000).
3.1.3.5 Pressures and their Impacts
The Member States are bound to collect and store data about the type and the dimension of
significant anthropogenic pressures on surface water bodies which are:
-
pollution from urban, industrial, agricultural and other installations and activities
-
water extraction for urban, industrial, agricultural and other uses (including
seasonal variations, total annual demand, and the loss of water in distribution
systems)
-
water flow regulation and its impact on overall flow characteristics and water
balances (including water transfer and diversion)
-
morphological alterations
-
land use patterns
-
other significant anthropogenic impacts
18
3.1
This information, together with existing data, is used to assess the probability that the water
bodies do not attain the environmental quality objectives (cf. European Commission 2000).
3.1.3.6 Surface Water Status
For the assessment of the ecological status of surface water bodies a catalogue of quality
elements and definitions has been worked out (European Commission 2000, see Table A-2:
Normative definitions of ecological status classifications, Appendix A).
Table 16: Quality elements for the classification of the ecological status of rivers.
Biological elements
Composition and abundance of aquatic flora
Composition and
invertebrate fauna
abundance
of
benthic
Composition, abundance and age structure of
fish fauna
Hydromorphological
elements Hydrological regime:
supporting the biological elements - quantity and dynamics of water flow
- connection to groundwater bodies
River continuity
Morphological conditions:
- river depth and width variation
- structure and substrate of the river bed
- structure of the riparian zone
Chemical and physicochemical General:
elements supporting the biological - Thermal conditions
elements
- Oxygenation conditions
- Salinity
- Acidification status
- Nutrient conditions
Specific pollutants:
- Pollution by all priority substances identified as
being discharged into the body of water
- Pollution by other substances identified as being
discharged in significant quantities into the body of
water
19
3.1
3.1.3.7 Monitoring Programmes
The Member States have to control the ecological and chemical status of surface water,
groundwater and protected areas. For this purpose monitoring programmes are designed in
order to establish a coherent and comprehensive overview of water status within each river
basin district for the duration of a river basin management plan (see Appendix A):
Surveillance monitoring programmes:
The information of these monitoring programmes is used to develop future monitoring
programmes with a higher quality, to assess the longterm changes of natural conditions and
the changes caused by human activities, and to complete and validate the impact
assessment procedure.
Operational monitoring programmes:
Operational monitoring is executed to determine the status of water bodies that potentially
fail the environmental objectives and to evaluate the changes of the status of such water
bodies resulting from the programmes of measures.
Investigative monitoring programmes:
Investigative monitoring programmes are applied when the reason for transgression are
unknown and to observe the dimension and impacts of unintended pollution. Additionally,
where surveillance monitoring shows that the environmental objectives cannot be reached
and operational monitoring has not already been designed to detect the causes of a water
body failing to achieve the environmental objectives.
The frequencies of monitoring are depending on quality elements and the water body type.
The monitoring frequencies for hydromorphological quality elements of rivers are 6 years for
continuity, continuous for hydrology, and 6 years for morphology (cf. European Commission
2000).
3.1.3.8 Classification of Ecological Status and Ecological Potential
The ecological status of assessed and monitored surface water bodies is classified with the
help of a scale with 5 levels (see Table 17). The Member States have to prepare a map for
each river basin district presenting the ecological status with the help of the correct colour
code (European Commission 2000).
Table 17: Classification of ecological status and corresponding colour codes.
Ecological Status Classification
1: high
2: good
3: moderate
4: poor
5: bad
Colour Code
Blue
Green
Yellow
Orange
Red
20
3.1
In the case of heavily modified and artificial water bodies a scale with 4 levels is used for the
classification. The illustration on a map is carried out with different colour codes depending
on the type of water body:
Table 18: Classification of ecological potential and corresponding colour codes.
Ecological Potential
Classification
Good and above
Moderate
Poor
Bad
Colour Code
Artificial Water Bodies
Heavily Modified Water
Bodies
Equal green and light grey Equal green and dark grey
stripes
stripes
Equal yellow and light grey Equal yellow and dark grey
stripes
stripes
Equal orange and light grey Equal orange and dark grey
stripes
stripes
Equal red and light grey Equal red and dark grey
stripes
stripes
3.1.3.9 Programmes of Measures
Each Member State is obligated to establish a programme of measures for each river basin
district taking account of the results of the analyses and reviews mentioned before (see
3.1.3.1 River Basin Districts) in order to achieve the environmental objectives (see 3.1.2
Environmental Objectives) at the latest nine years after the date of entry into force of the
WFD and all the measures shall be made operational at the latest 12 years after that date.
The programmes of measures are reviewed, and if necessary updated at the latest 15 years
after the date of entry into force of the WFD and every six years thereafter (cf. European
Commission 2000).
3.1.3.10 River Basin Management Plans
The Member States have to develop river basin management plans for every river basin
district and publish them within nine years after the date of entry into force of the WFD. The
management plans are reviewed and updated every six years (see Appendix A).
Concerning river basin management plans the WFD provides a public information and
consultation which means that:
-
“a timetable and work programme for the production of the plan, including a
statement of the consultation measures to be taken,
an interim overview of the significant water management issues identified in the
river basin, and
draft copies of the river basin management plan”,
are published and made available. To afford active involvement and consultation, the public,
including users, can comment on those documents at least six months (cf. European
Commission 2000).
21
3.1
3.1.3.11 Commission Report
The Commission has to “publish a report on the implementation of the Water Framework
Directive at the latest 12 years after the date of entry into force of the Directive and every six
years thereafter that is submitted to the European Parliament and to the Council”.
This report includes:
-
“a review of progress in the implementation of the Directive
a review of the status of surface water and groundwater in the Community
undertaken in coordination with the European Environment Agency;
a survey of the river basin management plans including suggestions for the
improvement of future plans;
a summary of the response to each of the reports or recommendations to the
Commission made by Member States;
a summary of any developed proposals, control measures and strategies;
a summary of the responses to comments made by the European Parliament and
the Council on previous implementation reports”.
In case of “breaches of the national provisions” concerning the implementation of the WFD,
the Member States determine “effective, proportionate, and dissuasive penalties”.
The Water Framework Directive entered into force when it was published in the Official
Journal of the European Communities on 22 December 2000. The Member States had to
enforce the laws, regulations and administrative provisions necessary to comply with the
Water Framework Directive at the latest 22 December 2003 (cf. European Commission
2000).
“Member States may not always reach good water status for all water bodies of a river basin
district by 2015, for reasons of technical feasibility, disproportionate costs or natural
conditions. Under such conditions that have to be specifically explained in the RBMPs, the
Water Framework Directive offers the possibility to Member States to engage into two further
six- year cycles of planning and implementation of measures until 2021 respectively 2027”
(CIS 2002).
22
3.2
The Austrian Water Act and the European Water Framework Directive
3.2 The Austrian Water Act and the European Water Framework
Directive
The European Water Framework Directive was transferred into the Austrian Water Act with
an amendment that was published in August 2003 (cf. Bundesgesetzblatt 2003). Generally,
Austria is obligated to achieve the good ecological status respectively the good ecological
potential for all waters by 2015 (respectively by 2021 or 2027).
As a consequence a number of regulations have been adopted to ensure the implementation
of the processes and measurements necessary to achieve the aims of the WFD. In this
connection, the Qualitätszielverordnung as well as the Gewässerzustandsüberwachungsverordnung play a major role.
3.2.1 Regulation on Objectives for Quality Elements according to the WFD
(Qualitätszielverordnung)
The purpose of this regulation are: the determination of the target conditions and the values
for the biological, hydromorphological, and general physical-chemical quality elements for the
high, good, moderate, poor, and bad ecological status. Furthermore, the definition of the
conditions for surface water body types that are important with regard to the deterioration
prohibition. This procedure is carried out type specific, i.e., separately for river types and lake
types as they differ because of landscape and biotic factors. The Qualitätszielverordnung
applies to all surface water bodies except artificial and heavily modified water bodies. The
goal is the evaluation of the quality of surface water bodies (cf. BMLFUW 2010).
For the high ecological status a high biological, high chemical, and high hydromorphological
evaluation is needed. The high hydromorphological status is defined primarily by the
absence of significant anthropogenic impacts.
The assessment of the good ecological status consists of biological and chemical
evaluations. It is assumed that the hydromorphological conditions are sufficiently integrated
via the biological quality elements as the morphological and hydrological conditions crucially
determine the diversity of habitats in water bodies and as a consequence the ecological
status (for the evaluated quality elements see also Appendix A, cf. Mühlmann 2010).
“The evaluation of the different ecological status classifications is carried out with the help of
the following quality elements:
High ecological status:
• Biological quality elements
• Physico-chemical quality elements
• Hydromorphological quality elements
Good ecological status:
• Biological quality elements
• Physico-chemical quality elements
The good ecological status can be achieved even when the hydromorphological status is not
in good condition.
Moderate, poor, bad ecological status:
• Biological quality elements“
23
3.2
As a consequence, a hydromorphological evaluation including 5 condition classes is not
necessary for the implementation of the Water Framework Directive. The directive claims to
prohibit the deterioration of the ecological status of water bodies, therefore it is necessary to
estimate the effects of anthropogenic alterations on the hydromorphological status of a water
body. For this reason benchmarks have been established. If they are met, the good
biological status is achieved with “high probability” (see 3.2.4 Manual for Hydromorphological
Investigation of the Status of Running Waters, cf. Mühlmann 2010).
3.2.2 Regulation on Monitoring the Conditions of Water Bodies
(Gewässerzustandsüberwachungsverordnung)
The results of the Ist-Bestandsanalyse (see 3.2.3 Investigation of the Hydromorphological
Status Quo of Austrian Water Bodies) serve as an essential basis for the development of a
new nationwide monitoring and measuring network. With the help of the monitoring the
actual status of water bodies can be ascertained which leads to the decision if future
measurements are necessary or not. The evaluation of the ecological status of water bodies
is regulated in the Qualitätszielverordnung (see 3.2.1).
The Gewässerzustandsüberwachungsverordnung illustrates the principles for the monitoring
by defining:
“1. The criteria for the installation of monitoring stations, the observed parameters, the
periods, and the frequency of measurements,
2. the methods and procedures for the sampling and the sample analysis as well as for the
evaluation of the data,
3. the specifications for the data processing and the data transfer.
The Gewässerzustandsüberwachungsverordnung applies to all surface water bodies
including artificial and heavily modified water bodies and to determined groundwater bodies.
Monitoring programmes have to be established for every time period for which a River Basin
Management Plan (River Basin Management Plan, see Appendix A) is enacted” (translated
from BMLFUW 2006).
3.2.3 Investigation of the Hydromorphological Status Quo of Austrian Water
Bodies
(Erhebung des hydromorphologischen Ist-Bestandes der Gewässer, Mühlmann 2005)
Article 5 of the WFD requires an investigation of the natural, economic, and socio-economic
conditions that are important as a basis for the National River Basin Management Plan. In
addition, the consequences of significant anthropogenic impacts and the previous
developments have to be assessed and recorded.
The Austrian inventory of the status of water bodies with the focus on pollution, physical and
hydromorphological pressures took place between 2004 and 2007. Besides lakes and
groundwater, running waters with a catchment area > 10km² were surveyed. The aim was
the assessment and analysis of the “risk” of water bodies to fail the good ecological status.
Subsequently, the collected data were used to define the targets that have to be achieved,
and to create monitoring programmes and measurement plans to improve the status of water
bodies. This process, the results and perspectives are illustrated in the National River Basin
Management Plan (NGP, see Appendix A) that has been published in 2009.
24
3.2
If sufficient existing data were available, no additional field surveys were carried out. For the
investigation of the hydromorphological status of running waters in Lower Austria data from
the former NÖMORPH survey were used (see 4.2.1 NÖMORPH – Ecomorphological
Mapping of Selected Running Waters in Lower Austria).
As the data set especially for rivers with a catchment area between 10km² and 100km² were
incomplete, a standardized and cost-effective “Screening method” was developed (cf.
Mühlmann 2005). For an overview over the used field manual and the parameters see
section 3.2.4 Manual for Hydromorphological Investigation of the Status of Running Waters.
3.2.4 Manual for Hydromorphological Investigation of the Status of Running
Waters
(Hydromorphologische Zustandserhebung von Fließgewässern)
The manual for the assessment of the hydromorphological status has been developed
together with the federal states of Austria and published by the Austrian Federal Ministry of
Agriculture, Forestry, Environment and Water Management. It is based on the procedures as
well as the features for survey and assessment required according to the European Standard
EN 14614 “Water quality – Guidance standard for assessing the hydromorphological features
of rivers” (see Table 19, cf. Mühlmann 2010). The features for survey and assessment are
grouped within 10 categories and cover the three broad zones of river environments: (a)
channel; (b) river banks/riparian zone; (c) floodplain (CEN 2002):
Table 19: Assessment categories, features, and attributes comprising a standard
hydromorphological assessment.
(CEN 2002)
No
1
2
Assessment
Categories
CHANNEL
Channel geometry
Substrates
Generic Features
Examples
Assessed
Planform
Braiding, sinuosity
Modification to natural planform
Longitudinal section
Gradient, long section profiles
Cross-section
Variations in cross-section shown
by depth, width, bank profiles, etc.
Concrete, bed-fixing
Artificial
Natural substrate types
3
Channel vegetation
&
Organic debris
of
Attributes
Embedded(non-movable boulders,
bedrock, etc.)
Large (boulders and cobbles)
Coarse (pebble and gravel)
Fine (sand)
Binding (silt and clay)
Organic (peat, etc.)
Management/catchment
Degree of siltation, compaction
impacts
Structural
form
of Emergent, free-floating, broadmacrophytes present
leaved submerged, bryophytes
Leafy and woody debris
Type and size of feature/material
25
3.2
4
Erosion/deposition
character
5
Flow
6
7
Vegetation management
Weed cutting
Features in channel and at Point bars, side bars, mid-channel
base of bank
bars and islands (vegetated or
bare);
Stable or eroding cliffs; slumped or
terraced banks
Flow patterns
Free-flow, rippled, smooth
Effect of artificial structures
(groynes, deflectors)
Flow features
Pools, riffles, glides, runs
Discharge regime
Off-takes, augmentation points,
water transfers, releases from
hydropower dams
Weirs, sluices across bed, culverts
Longitudinal
Artificial barriers affecting
continuity
as continuity of flow, sediment
affected by artificial transport and migration for
biota
structures
RIVER BANKS/ RIPARIAN ZONE
Bank structure and Bank materials
Gravel, sand, clay, artificial
modifications
Types of revetment/bank
Sheet piling, stone walls, gabions
protection
Bank profiles
8
Vegetation
type/ Structure of vegetation
structure on banks
and adjacent land
Vegetation management
Cliffs, berms, re-graded, trampled,
eroding, depositing
Vegetation types, stratification,
continuity
Bank mowing, tree felling
Types of land-use, extent Agriculture, urban development
and types of development
FLOODPLAIN
9
10
Adjacent land-use Types of land-use, extent Floodplain
forest,
and
and types of development
urban development
associated features
agriculture,
Types
of
open Ancient fluvial/floodplain features
water/wetland features
(cut-off
meanders,
remnant
channels, bog)
Artificial water features (irrigation
channels, fish ponds, gravel pits)
Degree of constraint to Embankments
and
levees
potential mobility of river (integrated with banks or set back
channel and water flow from river), flood walls and other
across floodplain
constraining features
Degree
of
(a)
lateral connectivity
of
river
and
floodplain;
(b)
lateral movement of
river channel
Continuity of floodplain
Any major artificial structures
partitioning the floodplain
26
3.2
The following section gives an overview of the manual used for the
hydromorphological investigation of the status of running waters in Austria
(translated from Mühlmann 2010):
Stretches with a length of 500m are assessed with the help of existing data, aerial photos
and field surveys. The method uses 5 condition classes only for the evaluation of the
morphological parameter groups. Hydrological impacts and impacts caused by transverse
structures are assessed with the help of reference values without using a system with 5
classes.
3.2.4.1 Parameter Groups
3 assessed parameter groups are decribed in the manual: Hydrology, Transverse Structures,
and Morphology.
Hydrology
Residual Flow Water Stretches
The assessment of significant impacts on the hydromorphological condition caused by water
diversion is carried out with the help of the following criteria. If one of them occurs, the good
ecological status is failed:
•
•
•
•
Mean water discharge of residual stretch < Mean daily natural low water discharge
per year or
Low water discharge of residual stretch < Natural daily low water discharge
Mandatory water input for the residual flow stretch absent or only periodical
Water diversion in a residual flow stretch
Stretches that are dry periodically or all-the-year because of too little residual water
The Qualitätszielverordnung (QZVO, 2010) contains reference values for residual water
stretches to obtain the high respectively the good ecological status with “high probability”
(translated from Mühlmann 2010).
Stretches influenced by Hydropeaking
Small and medium running waters are significantly influenced by hydropeaking when the
hydropeaking ratio is > 1:5. In the case of large rivers every hydropeaking operation is seen
as a significant impact.
Parameters:
-
Actual hydropeaking ratio
Frequency of hydropeaking operations
Velocity of water flow fluctuations
Length of impact (% of 500m stretch)
The Qualitätszielverordnung (QZVO, 2010) contains reference values for stretches
influenced by hydropeaking to obtain the good ecological status with “high probability”
27
3.2
Impounded Stretches
The impact of an impoundment is significant and the good ecological status is missed when:
-
anthropogenic reduction of the mean flow velocity to 0.3m/s during mean discharge
conditions (is the length of the impounded reach shorter than 5 times the wetted
width, the impact is not significant)
impoundment length > 100m, catchment area < 100km²
impoundment lenght > 500m, catchment area > 100km²
The Qualitätszielverordnung (QZVO, 2010) contains reference values for residual water
stretches to obtain the high respectively the good ecological status with “high probability”
Transverse Structures
For the hydromorphological evaluation transverse structures stretching across the whole
river width are investigated. They interrupt the river continuum and therefore act as migration
barrier for organisms.
Types of Transverse Structures:
-
Hydropower Plants (Dams, Weirs)
(Flood) Protection Structures (e.g., sills, river bottom ramps, drop structures, bedload
barriers)
Transverse Structures for other aims (e.g., pipes, water diversion structures not for
hydropower)
Natural drops > 1m high
Chain of at least 5 sequent drop structures
The manual distinguishes between structures passable and not passable for potential
existing fish species using reference values (every species has to be able to swim over or
through a barrier or it is assesses as not passable):
-
Drop structure with detached water jet, not passable for fishes
Drop structure with detached water jet, fishes able to swim through
Drop structure with clinging water jet, not passable for fishes
Drop structure with clinging water jet, fishes able to swim through (translated from
Mühlmann 2010)
Morphology
River morphology is assessed using main and operational parameters that are evaluated
using attributes assigned to a scale of 5 levels according to the WFD:
Main Parameters
•
•
Riparian Dynamic Processes
Riverbed Dynamic Processes
Optional Parameters
•
•
•
•
Morphological River Type - Course
Substrate Composition
Riverbed Morphology
Riparian Vegetation” (translated from Mühlmann 2010)
28
3.2
3.2.4.2 Evaluation of the High Hydromorphological Status
“According to the QZVO a high hydromorphological status is reached, if no or only very
insignificant pressures and impacts are influencing a water body” (translated from Mühlmann
2010).
Table 20: Scheme for the evaluation of the high hydromorphological status according
to the “Qualitätszielverordnung” (stretch 500m).
(translated from Mühlmann 2010)
Parameter
Evaluation
Parameters Morphology
Riparian dynamic processes (5 classes)
Riverbed dynamic processes (5 classes)
1
1
Parameters Hydrology
Stretch influenced by water diversion
Stretch influenced by hydropeaking
Stretch influenced by impoundment
River Continuum
Interruptions of river continuum
Water diversion < 20% of the annual discharge
or
Water diversion < 10% of the lowest daily low
water (NQt) when:
- from October to March the discharge is lower
than the mean water discharge
or
- from April to September the discharge is
lower than the mean annual water discharge
No artificial hydropeaking
Only isolated anthropogenic reduction of flow
velocity along very short stretches
Only transverse structures that allow
undisturbed migration of aquatic organisms
and natural sediment transportation
29
3.2
3.2.4.3 Designation of the Good Hydromorphological Status
“The hydromophological preconditions to reach the good ecological status are defined using
the conditions needed to reach the reference values for the good biological status.
The Qualitätszielverordnung (see 3.2.1) describes in detail the conditions and values
necessary to achieve the good ecological status for the biological quality elements with a
“high probability”. The reference values are also important to estimate the consequences of
artificial river alterations in the future” (translated from Mühlmann 2010) .
Table 21: Scheme for the evaluation of the good hydromorphological status according
to the “Qualitätszielverordnung” (stretch 500m).
(translated from Mühlmann 2010)
Parameter
Evaluation
Parameters Morphology
Riparian dynamic processes (5 classes)
Riverbed dynamic processes (5 classes)
2
2
Parameters Hydrology
Water diversion
The defined minimum discharge has to be
constantly existent.
The determined values for the minimum
water depth and the minimum flow velocity
relevant for fish habitats have to be
maintained.
Hydropeaking
Impoundment
Transverse Structures
Interruptions of the river continuum
A near-natural and dynamic water flow
ensures
- the natural rearrangement of the riverbed
and thus a typical substrate composition,
- the necessary current during the spawning
season,
- a habitat diversity that fulfils the
requirements of species of different ages
during different seasons,
- the typical oxygen and water temperature
conditions.
Ratio of downsurge:surge < 1:3 and during
downsurge at least 80% of the river bottom is
covered with water that is wetted during
surge.
Impacts of hydropeaking on large rivers have
to be assessed individually.
Anthropogenic reduction of the mean flow
velocity < 0.3m/s only along very short
stretches
- Existent transverse structures passable for
fishes throughout the whole year.
- The connections between habitats are not
heavily disturbed.
30
3.2
3.2.5 Identification and Designation of Heavily Modified and Artificial Water
Bodies
(Ausweisung von „künstlichen“ und „erheblich veränderten“ Oberflächenwasserkörpern)
According to the Water Framework Directive surface water bodies are assigned to 3
categories:
-
natural surface water bodies
artificial surface water bodies (AWB, created by human activity)
heavily modified surface water bodies (HMWB)
“HMWB are bodies of water which, as a result of physical alterations by human activity, are
substantially changed in character and cannot, therefore, meet "good ecological status"
(GES). The CIS guidance “On the identification and designation of heavily modified and
artificial water bodies” defines a water body as artificial when it “has been created in a
location where no water body existed before and which has not been created by the direct
physical alteration or movement or realignment of an existing water body". Water bodies that
have been modified and moved to another location are regarded as HMWB.
Instead of the good ecological status, the environmental objective for HMWB and for AWB is
the good ecological potential (GEP), which has to be achieved by 2015. However, the
achievement of the good chemical status and the deterioration prohibition are also obligatory
for AWBs and HMWBs.
The designation of HMWB and AWB is optional. Member States do not have to designate
modified water bodies as HMWB or AWB. Where modified or artificial waters are not
designated the objective is be the good ecological status” (CIS 2002).
According to the WFD [Art. 4(3)] a body of surface water is designated as artificial or
heavily modified, when:
“(a) the changes to the hydromorphological characteristics of that body which would be
necessary for achieving good ecological status would have significant adverse effects on:
-
the wider environment
navigation, including port facilities, or recreation
activities for the purposes of which water is stored, such as drinking-water supply,
power generation or irrigation
water regulation, flood protection, land drainage, or
other equally important sustainable human development activities
(b) the beneficial objectives served by the artificial or modified characteristics of the water
body cannot, for reasons of technical feasibility or disproportionate costs, reasonably be
achieved by other means, which are a significantly better environmental option.
Such designation and the reasons for it shall be specifically mentioned in the river basin
management plans required under Article 13 and reviewed every six years” (European
Commission 2000).
31
3.2
3.2.6 Evaluation of Artificial and Heavily Modified Water Bodies - Definition of
the Ecological Potential
“Once designated as HMWB or AWB, the environmental objectives are “good ecological
potential” (GEP) and good chemical status. Where the results of risk assessments indicate
that a HMWB or AWB is likely to fail to achieve GEP, Member States must establish an
appropriate set of measures to improve the ecological potential of a water body with the
aim of achieving GEP by 2015” (CIS 2002).
“The ecological targets for natural, artificial and heavily modified water bodies are set in
relation to reference conditions. For HMWB and AWB the reference is the maximum
ecological potential (MEP)” (CIS 2002). See Appendix A for the definitions for maximum,
good and moderate ecological potential for heavily modified or artificial water bodies with
regard to the quality elements.
3.2.6.1 Guidance for the Evaluation of Heavily Modified Water Bodies
The Austrian guidance for the evaluation of heavily modified water bodies (Eberstaller et al.
2009) describes as “fundamental biological objective a self-perpetuating fish population with
a sufficient biomass that comes to some extent close to the population typical for a water
body. As a consequence, fish stocks are used to define the ecological potential (see
3.2.6.1.1 Methodical Procedure to establish the Maximum and the Good Ecological
Potential). Even though stocking measures are not necessary, severe episodic population
drops can occur due to critical events” (translated from Eberstaller et al. 2009).
“The requirements for a self-perpetuating fish population are described as follows:
-
Availability of appropriate habitats for every age respectively needs of particular fish
species,
Linkage of habitats to allow migration (spawning gounds, juvenile habitats, etc.),
Minimum stock size of the individual species to be self-perpetuating in a river stretch,
Minimum quantity of adult fishes respectively connections to other populations to
ensure genetic diversity” (translated from Eberstaller et al. 2009).
Table 22: Biological Definition of the maximum, good, moderate, poor, and bad
ecological potential.
(translated from Eberstaller et al. 2009)
Biological Definition of the Maximum Ecological Potential
The maximum fish-ecological potential differs only slightly from the good fish-ecological
status. The majority of the flagship species defined in the general principle and at least a
moderate part of the typical secondary species is able to develop independent populations
with sufficient case-specific biomass.
Biological Definition of the Good Ecological Potential
A water body is in the condition of good ecological potential, when at least an essential part
of the flagship species and at least a (minor) part of the typical secondary species is able to
maintain a self-perpetuating stock with sufficient case-specific biomass. Existing species,
species composition, and population structure differ significantly from the good ecological
status and slightly from the maximum ecological potential.
32
3.2
Biological Definition of the Moderate Ecological Potential
A water body is in the condition of moderate ecological potential, when at least a moderate
part of the flagship species and at least a very low part of the typical secondary species is
able to develop self-perpetuating populations.
Biological Definition of the Poor Ecological Potential
A water body is in the condition of poor ecological potential, when at least a minor part of the
flagship species is able to develop self-perpetuating populations. Self-perpetuating
populations of the typical secondary species are barely existent.
Biological Definition of the Bad Ecological Potential
A water body is in the condition of bad ecological potential, when self-perpetuating
populations of the flagship species and the typical secondary species are absent.
3.2.6.1.1 Methodical Procedure to establish the Maximum and the Good
Ecological Potential
“If the biological objective (the good ecological potential) cannot be reached due to local
limiting factors, the maximum and the good potential have to be identified with the help of
feasible measurements. The main purpose of the measurements is to achieve the good
ecological potential through creation and linkage of habitats. This means migration
possibilities for the fish fauna in the main channel, side channels, and tributaries, appropriate
structures in the river bed, and roughly natural discharge conditions.
Basically the following steps have to be carried out to establish the maximum respectively
the good ecological potential:
1. Determination of the technically feasible measurements for the respective water
body/stretch that do not have significant adverse effects on the usage.
2. Biological effects of determined measurements: Estimation of the developing habitat
conditions and the resulting improvements for characteristic groups of typical fish populations
( = biological definition of the maximum ecological potential).
3. Specification of the tolerable marginal deviation from the biological conditions of the
maximum potential ( = biological definition of the good ecological potential).
4. Selection of the measurements (measurement combinations) necessary to reach the good
ecological potential” (translated from Eberstaller et al. 2009).
33
3.3
Assessment of Surface Waters in the USA
3.3 Assessment of Surface Waters in the USA
“The Federal Water Pollution Control Act, or Clean Water Act (CWA), is the principal law
governing pollution of the surface waters of the USA. Originally enacted in 1948, it was totally
revised by amendments in 1972 that gave the act its current shape. The 1972 legislation
declared as its objective the restoration and maintenance of the chemical, physical, and
biological integrity of the nation’s waters. Two goals also were established: zero discharge of
pollutants by 1985 and, as an interim goal and where possible, water quality that is both
“fishable” and “swimable” by mid-1983. While those dates have passed, the goals remain,
and efforts to attain them continue. The ambitious programs for water quality improvement
have since been expanded and are still being implemented by industries, municipalities and
others. The Congress made fine-tuning amendments in 1977, revised portions of the law in
1981, and enacted further amendments in 1987” (Copeland 2010).
“A critical section (305[b]) of the CWA calls for periodic accounting of the success or failure
of efforts to protect and restore US waters. Over the years, several groups have reviewed the
available data and concluded that they do not adequately describe the condition of US
waters” (Shapiro et al. 2008).
3.3.1 Wadeable Streams Assessment
“The Wadeable Streams Assessment (WSA) presents the first set of results from what will be
a long-term partnership between the US Environmental Protection Agency (USEPA), the
individual states, tribal nations, and other federal agencies. The goal of this partnership is to
fill critical information gaps that remain a deterrent to the ability to determine whether policies
and investments have resulted in improvement of US water resources (Shapiro et al. 2008).
The WSA is a first-ever statistically-valid survey of the biological condition of small streams
throughout the USA. The EPA worked with the states to conduct the assessment in 20042005. The WSA is designed like an opinion poll: that is, 1,392 sites were selected at random
to represent the condition of all streams in regions that share similar ecological
characteristics” (http://www.epa.gov 2011).
“The WSA collaboration began as a partnership among 12 western states, EPA Regions 8,
9, and 10, and EPA’s Western Ecology Division (Environmental Monitoring and Assessment
program Western Pilot Study, EMAP-W - see 3.3.3 Environmental Monitoring and
Assessment Program Western Pilot Study) before it was expanded to include the entire
United States (USEPA 2006). The assessment utilized data from EMAP-W and a new field
survey in the eastern 36 States. The same sample survey design and the same protocols
were used for the eastern States as were used for EMAP-W” (USEPA 2004).
“The Environmental Monitoring and Assessment Program (EMAP) was a research program
run by EPA’s Office of Research and Development (ORD) to develop the tools necessary to
monitor and assess the status and trends of national ecological resources. EMAP collected
field data from 1990 to 2006. EMAP's goal was to develop the scientific understanding for
translating environmental monitoring data from multiple spatial and temporal scales into
assessments of current ecological condition and forecasts of future risks to natural
resources” (http://www.epa.gov 2010).
“The WSA highlighted significant problems affecting streams and established a nationally
consistent baseline that can be used to compare to results fom future studies”
(http://www.epa.gov 2011).
The assessment is now combined with a second continuative national survey of streams: the
National Rivers and Streams Assessment.
34
3.3
3.3.2 The National Rivers and Streams Assessment (NRSA)
“The National Rivers and Streams Assessment (NRSA) is a study of the condition of the
flowing waters. It is the first-ever baseline statistical survey of the US’ larger rivers (including
the Great Rivers).
The NRSA is one of a series of water surveys being conducted by the U.S. Environmental
Protection Agency, states, tribes, and other partners. In addition to rivers and streams,
partners are also studying coastal waters, wetlands and lakes in a revolving sequence. The
purpose of these surveys is to generate statistically-valid and environmentally relevant
reports on the condition of the Nation’s water resources.
The NRSA is designed to answer three key questions:
1. What percentage of the Nation’s rivers and streams are in good, fair, and poor condition
for key indicators of ecological and human health?
2. What is the relative importance of key stressors such as nutrients and habitat condition?
3. What are the trends in stream condition since the Wadeable Streams Assessment?
The sampling design for this survey is a probability-based network that provides statisticallyvalid estimates of condition for the population of rivers and streams with a known confidence.
A total of 2,400 sample sites were sampled in 2008 and 2009 to represent the condition of
rivers and streams across the country, 1,200 in each of the two categories of waters
(wadeable and non-wadeable). Of the wadeable sites, 450 were selected from the original
2004 Wadeable Streams Assessment” (USEPA 2011)
“Data are now being validated and analyzed, and the final NRSA report is expected in 2012.
The results from this survey will also be used to compare more recent water quality
conditions in small streams with the findings of the Wadeable Streams Assessment” (USEPA
2011).
3.3.3 Environmental Monitoring and Assessment Program Western Pilot Study
The Physical Habitat Characterization, executed and analyzed for this thesis, was part of the
Environmental Monitoring and Assessment Program Western Pilot Study (EMAP-W) that
was executed from 2000 to 2004. The procedures of the EMAP-W included collecting field
measurement data and/or acceptable samples for several response and stressor indicators,
such as aquatic vertebrate assemblages, benthic macroinvertebrate assemblages,
periphyton assemblages, water chemistry, physical habitat, invasive riparian plants, and fish
tissue contaminants. The Physical Habitat Characterization approach used for the Western
Pilot Study was applied nationally in the course of the NRSA. The data from these habitat
characterizations is used to calculate the summary indicators of physical habitat quality in the
national assessments.
The basics of the Physical Habitat Characterization procedure had been developed before by
Philip R. Kaufmann and E. George Robison (1994, 1998) and constitute the standardmethod used by the U.S. Environmental Protection Agency (USEPA) for the EMAP, by
various Regional Environmental Monitoring and Assessment Programs (R-EMAPs) in many
states and EPA Regions, by several National Parks, and by private industries. Some
changes and ameliorations were made for the Western Pilot Study (cf. Peck et al. 2006 and
Kaufmann et al. 1999).
“The U.S. EPA Environmental Monitoring and Assessment Program (EMAP) assembled
crews to collect over 1500 samples on 1340 perennial streams throughout the western U.S.
The project included both wadeable streams and non-wadeable rivers, and sampled sites
that were either randomly chosen to be representative of the entire population of flowing
waters in the West, or hand picked to represent the best possible condition (“reference
35
3.3
sites”). This ambitious project was carried out in partnership with twelve western states
(Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South
Dakota, Utah, Washington and Wyoming), the U.S. Geological Survey (USGS), multiple
universities, and Environmental Protection Agency (EPA) Regions 8, 9 and 10.
The results respectively the obtained information fill an important gap in meeting
requirements of the Clean Water Act” (CWA, see 3.3 Assessment of Surface Waters in the
USA, Stoddard et al. 2005).
The EMAP-W had 4 purposes:
-
-
“Report on the ecological condition of all perennial flowing streams and rivers with the
exception of those considered “Great Rivers,” (the lower Columbia, Snake, Missouri
and Colorado Rivers).
Describe the ecological condition of western streams and rivers with direct measures
of plants, fish, and other aquatic life.
Identify and rank the relative importance of chemical, physical and biological
disturbances affecting stream and river condition.
Encourage states to include these design and measurement tools as a portion of their
State monitoring programs, so that future condition assessments will be ecologically
and statistically comparable both regionally and nationally” (Stoddard et al. 2005).
“The ecological condition of streams and rivers was estimated by analyzing the composition
and relative abundance of key biotic assemblages - in the case of EMAP-W, the emphasis
was on aquatic vertebrates (fish and amphibians) and macroinvertebrates (larval insects,
crustaceans, worms and mollusks). The center of attention was biological integrity, because
of the inherent capacity of biological organisms and assemblages to integrate the chemical
and physical stressors that affect them over time” (Stoddard et al. 2005).
The approach in collecting the data for this assessment has two key characteristics:
“First, it focuses on the direct assessment of biological indicators, and on the chemical and
physical properties of streams and rivers that are most likely to have effects on biological
communities. Second, it uses an innovative statistical design that ensures that the results are
representative of the region, and that allows to extend this statistical certainty in the results to
subregions of the West (e.g., to major ecological regions) where desired.
The assessment is divided into two major categories:
- The documentation of the ecological conditions of streams and rivers in the West,
through the use of direct measures of their resident biological assemblages: aquatic
vertebrates and benthic macroinvertebrates.
- The assessment of the relative importance of potential stressors on those
assemblages, based on direct measures of their chemical, biological and physical
habitat” (Stoddard et al. 2005).
3.3.3.1 Physical Habitat Stressors
There are many stressors influencing aquatic organisms when river habitats are altered or
modified. EMAP-W focused on four specific aspects of physical habitat (from Stoddard et al.
2005):
Streambed stability - “streams and rivers adjust their channel shape and streambed particle
size in response to the supply of water and sediments from their drainage areas. One
measure of this interplay between sediment supply and transport is relative bed stability
36
3.3
(RBS). The measure of RBS used in this assessment is a ratio comparing the particle size of
observed sediments to the size sediment each stream can move or scour during its flood
stage, based on the size, slope and other physical characteristics of the stream channel. The
RBS ratio differs naturally among regions, depending upon landscape characteristics that
include geology, topography, hydrology, natural vegetation, and natural disturbance history.
Values of the RBS Index can be either substantially lower (finer, more unstable streambeds)
or higher (coarser, more stable streambeds) than those expected based on the range found
in least disturbed reference sites - both high and low values are considered to be indicators
of ecological stress. Excess fine sediments can destabilize streambeds when the supply of
sediments from the landscape exceeds the ability of the stream to move them downstream.
This imbalance results from numerous human uses of the landscape, including agriculture,
road building, construction and grazing. Lower than expected streambed stability may result
either from high inputs of fine sediments (from erosion) or increases in flood magnitude or
frequency (hydrologic alteration). When low RBS results from fine sediment inputs, stressful
ecological conditions can develop because fine sediments begin filling in the habitat spaces
between stream cobbles and boulders. The instability (low RBS) resulting from hydrologic
alteration can be a precursor to channel incision and arroyo formation. Perhaps less well
recognized, streams that have higher than expected streambed stability can also be
considered stressed - very high bed stability is typified by hard, armored streambeds, such
as those often found below dams where fine sediment flows are interrupted, or within
channels where banks are highly altered” (e.g., paved or lined with rip-rap, Stoddard et al.
2005).
Habitat complexity - “the most diverse fish and macroinvertebrate assemblages are found
in streams and rivers that have complex forms of habitat: large wood, boulders, undercut
banks, tree roots, etc. Human use of streams and riparian areas often results in the
simplification of this habitat, with potential effects on biotic integrity. For this assessment, a
measure is used that sums the amount of in-stream habitat consisting of undercut banks,
boulders, large pieces of wood, brush, and cover from overhanging vegetation within a meter
of the water surface” (Stoddard et al. 2005).
Riparian Vegetation - “the presence of a complex, multi-layered vegetation corridor along
streams and rivers is a measure of how well the stream network is buffered against sources
of stress in the watershed. Intact riparian areas can help reduce nutrient and sediment runoff
from the surrounding landscape, prevent bank erosion, provide shade to reduce water
temperature, and provide leaf litter and large wood that serve as food and habitat for stream
organisms. The presence of canopy trees in the riparian corridor indicates longevity; the
presence of smaller woody vegetation typically indicates that riparian vegetation is
reproducing, and suggests the potential for future sustainability of the riparian corridor. For
this assessment a measure of riparian vegetation complexity is used that sums the amount
of woody cover provided by three layers of riparian vegetation: the ground layer, woody
shrubs, and canopy trees” (Stoddard et al. 2005).
Riparian Disturbance - “the vulnerability of the stream network to potentially detrimental
human activities increases with the proximity of those activities to the streams themselves. A
direct measure of riparian human disturbance tallies eleven specific forms of human activities
and disturbances (e.g., roads, landfills, pipes, buildings, mining, channel revetment, cattle,
row crop agriculture, silviculture) along the stream reach, and weights them according to how
close to the stream channel they are observed” (Stoddard et al. 2005).
37
3.3
Ranking of Stressors
“An important prerequisite to making policy and management decisions is an understanding
of the relative magnitude or importance of potential stressors. There are multiple ways to
define “relative importance” with stressors. One aspect to consider is how common each
stressor is, i.e., what is the extent, in kilometers of stream, of each stressor and how does it
compare to the other stressors? Or the consideration of the severity of each stressor, i.e.,
how much effect does each stressor have on biotic integrity, and is its effect greater or
smaller than the effect of the other stressors?” (Stoddard et al. 2005).
Relative Extent
“EMAP-W ranked chemical, biological and physical stressors according to the proportion of
stream and river length for each that is in most-disturbed condition. The results were
presented for all of the West and for each climatic region, with the stressors ordered
according to their relative extent west-wide. Riparian disturbance was the most pervasive
stressor west-wide, and in each of the climatic regions. Across all of the West, fully 47% of
the stream length showed significant signs of riparian disturbance.
The least common stressors were the two non-native macroinvertebrate groups (non-native
crayfish and Asian clam), where only 2% of stream length west-wide were affected. Between
these two extremes (riparian disturbance vs. non-native macroinvertebrates), the different
types of stressors (chemical, physical and biological) ranked without any particular pattern.
The top three stressors west-wide were representatives of the physical (riparian
disturbance), biological (non-native vertebrates) and chemical (nitrogen) classes of stressor”
(Stoddard et al. 2005).
Relative Risk
“In order to address the question of severity of stressor effects, EMAP-W used the concept of
“relative risk”: How much more likely is a stream to have poor biotic integrity if a stressor is
present (or found in high concentrations) than if it is absent (or found in low concentrations)?
In technical terms, the relative risk ratio represents the proportional increase in the likelihood
of finding a biological indicator in the most-disturbed class when the stressor's condition in
the same stream is also in the most-disturbed class. As different biological assemblages and
different aspects of those assemblages (e.g., biotic integrity vs. taxa loss) are expected to be
affected by different stressors, relative risk was calculated separately for each of the
ecological conditions indicators presented in the EMAP-W assessment” (Stoddard et al.
2005).
3.3.3.2 Reference Conditions
“Because of the difficulty of estimating historical conditions for many indicators, EMAP-W
used “Least-Disturbed Condition” as reference. “Least Disturbed Condition” is found in
conjunction with the best available physical, chemical and biological habitat conditions given
the present state of the landscape. It is described by evaluating data collected at sites
selected according to a set of explicit criteria defining what is “best” (or least disturbed by
human activities). These criteria vary from region to region, and were developed iteratively
with the goal of identifying the least amount of ambient human disturbance in each ecoregion
of the West. The range of conditions found in these “reference sites” describes a distribution
of values, and extremes of this distribution are used as thresholds to distinguish sites in
relatively good condition from those that are clearly not.
A collection of least disturbed sites was identified in each region - either probability sites or
handpicked sites - and was sampled using methods identical to those used at the sites
assessed for the EMAP-W” (Stoddard et al. 2005).
38
3.3
3.3.3.3 Extent of Resource - Sampling Sites
“The sampling frame used to select the sites for sampling in EMAP-W was based on the
perennial stream network contained in EPA’s River Reach file (known as RF3). RF3 is a
digitized version of 1:100,000 scale USGS topographic maps, showing both perennial and
non-perennial streams. The total length of the RF3 stream network in the EMAP West region
that is labeled perennial is 628,625 km. A significant proportion of this total (207,770 km, or
33%) was found through site evaluation and sampling to be either non-perennial, or nontarget in some other way (e.g., wetlands, reservoirs, irrigation canals). The remaining “target
stream length” (420,855 km) represents the portion of the sampling frame that meets the
criteria for inclusion in this assessment (i.e., perennial streams and rivers). A part of the
target stream length (73,967 km, or 18%) was not accessible to sampling because crews
were denied access by landowners. An additional portion of the target stream length (42,344
km, or 11%) was physically inaccessible due to physical barriers or other unsafe local
conditions. The remainder of the sampling frame constitutes the assessed length of stream
for the EMAP-W 304,544 km, representing 48% of the original frame length.
The assessed sites were chosen according to a probability design, where each site had a
known probability of being selected for sampling, and collectively the sites were statistically
representative of the population of flowing waters in the region. Within the EMAP-W region,
several special interest areas were identified for additional site selection. The higher density
probability design in these areas allowed to make future, stand-alone, assessments of each
area” (Stoddard et al. 2005).
39
4.2
Characterization Survey Methods
4 Methodology
4.1 Approach
In the course of this project the Austrian NÖMORPH (Strukturkartierung ausgewählter
Fließgewässer in Niederösterreich) and the Physical Habitat Characterization that was part
of the EMAP-W (see 3.3.3 Environmental Monitoring and Assessment Program Western
Pilot Study) have been executed and analyzed. The field work took place in the catchment
area of the river Traisen in Lower Austria (see 5 Study Area).
As the Physical Habitat Characterization is a complex assessment method, a voyage to the
USA made it possible to get a better understanding of the field application, the following
processing of the data, and the working procedures in the Pacific Northwest. The beginning
of the journey was a stay in Corvallis, Oregon. There the introduction to the field survey was
carried out by Philip R. Kaufmann who had participated in the development of the Physical
Habitat Characterization and is a principal investigator of the Western Ecology Division that
provides information to the Environmental Protection Agency.
Philip Kaufmann also established contacts with several field crews for further field practice.
This trainings included field surveys with a crew from the Oregon Department of
Environmental Quality in the Trask river watershed and the John Day River watershed, and
with a co-worker of Demeter Design, a private environmental research firm, in the Tillamook
river watershed.
4.2 Characterization Survey Methods
The field survey as well as the evaluation procedures of the NÖMORPH method and the
Physical Habitat Characterization method differ from one another. This chapter descibes the
methods, their application in the field, and the calculations of the collected data.
4.2.1 NÖMORPH – Ecomorphological Mapping of Selected Running Waters in
Lower Austria
(Strukturkartierung ausgewählter Fließgewässer in Niederösterreich)
The following sections concerning the characterization of the NÖMORPH method and
its procedures have been extracted from Amt der NÖ Landesregierung (2002) and
from freiland Umweltconsulting (2001):
4.2.1.1 Background, Tasks and Aims
In November 1998 the Department of Water Management (Abteilung Wasserwirtschaft) of
the federal government of Lower Austria commissioned the “freiland Umweltconsulting” with
the ecomorphological mapping of selected running waters in Lower Austria. From the
beginning until the end of the project in June 2001, 2000 river kilometers were surveyed in
Lower Austria.
40
4.2
The main aims of the NÖMORPH method were:
-
“To provide a first report and basis of evaluation of water ecological aspects during
water management projects, in particular concerning flood protection works and
hydropower utilization
Planning principles for projects improving the ecological functionality of impacted and
degraded streams
Determination of the importance of the protection of running waters on the basis of
region transcending comparisons
Documentation of changes (preservation of evidence)
Illustration of correlations between hydromorphological water body condition and
biological water quality
The following tasks were set for this project:
-
Mapping at a scale of 1:25,000 (ÖK 25) and description of 2000 kilometers of river
stretches
Creation of a database for the administration of the collected data
Integration of the data into the Wasserdatenverbund (WDV - an information system
that registers, manages, and evaluates the water data of Lower Austria)
Possibility of an independent mapping and computerized processing by employees of
the regional government authority of Lower Austria” ( translated from Amt der NÖ
Landesregierung 2002)
The following sections concerning the characterization of the NÖMORPH method and
its procedures have been translated from freiland Umweltconsulting 2001:
4.2.1.2 Characterization
Basically, the NÖMORPH method analyzes the deviation of the current status from the typespecific status - the target state that is represented by reference conditions.
Two methods are the basis for the NÖMORPH method:
-
Ökomorphologische Gewässerbewertung in Oberösterreich (Ecomorphological
evaluation of water bodies in Upper Austria) according to Werth with the focus on
morphology (river bed, riparian structure), and riparian vegetation. The value benefit
analytical approach uses selected parameters to assess the difference to the
unaffected water body condition. As the reference conditions are not defined, it is the
surveyor’s responsibility to create an image of the natural and type-specific
conditions. The inventory includes the inspection of the whole stream and the
evaluation is carried out with the help of 4 main condition classes and 3 intermediate
condition classes.
-
Ökomorphologische
Kartierung
der
Hauptgewässer
in
Hartberg
(Ecomorphological mapping of the main water bodies in Hartberg, Styria), edited by
freiland in 1996. This method is adapted according to Werth. The emphasis is the
value benefit analytical examination in consideration of river types.
The “Ökomorphologische Kartierung der Hauptgewässer in Hartberg” was adopted and
adapted corresponding to the regional government authority of Lower Austria (freiland
Umweltconsulting 2001).
For the NÖMORPH method a river is surveyed continuously from mouth to source during
mean or low flow conditions. Therefor, it is devided into single river reaches - for each reach
pre-defined attributes that are assigned to 5 summarizing parameters are assessed and
41
4.2
estimated. If one parameter changes (irrespective of the change of the numerical value of
this parameter), a new reach, with a length of at least 100 m, begins and is surveyed with the
help of new forms.
Forms are numbered following the mapping procedure upstream - left and right banks are
assessed and numbered separately because they usually do not have the same
morphological structures (the imaginary division line runs in the middle of the channel) so
that the left-riparian stretch can be longer or shorter than the right-riparian stretch. Similarly,
they have to be recorded on the ÖK 25 (map scale 1:25,000). The stretch identification code
and the identification code of the single forms for the particular streams have to conform.
Impoundments and Residual Water Stretches
Impoundments and residual water stretches are also assessed to estimate their ecological
and morphological potential. Impoundments are surveyed from the head of the reservoir to
the impoundment structure but not evaluated.
The evaluation of residual water stretches is performed with the help of an imaginary meanwater level. It is reported as water abstraction stretch but the procedure of the allocation to a
condition class is the same as for free flowing stretches.
Structures interrupting the River Continuum
Natural and artificial structures that interrupt the river continuum are reported with an ID
number as punctual information on the additional form (see Appendix C) and marked on the
map.
Artificial structures are divided into 4 categories:
-
drop structure
river bottom ramp
sill
weir
Figure 1: Examples for structures interrupting the river continuum.
(freiland Umweltconsulting 2001)
Backwaters
Backwaters (e.g., oxbows) that are visible from the main water body are also reported as
punctual information on the additional form (see Appendix C) to get a deeper insight into the
transition area between a river and its environment. Tributaries are not seen as backwaters
and therefore not included in the assessment (freiland Umweltconsulting 2001).
42
4.2
4.2.1.2.1 Reference Conditions
The assessment is based on the recording and evaluation of morphological and structural
parameters in and around water bodies that are determinant for the role of water bodies as a
habitat.
The NÖMORPH method assumes that the best biological conditions exist in anthropogenic
undisturbed habitats (equals to condition class 1). Therefore, the “natural” status before the
beginning of the systematically river training is the basis of the evaluation. If this is no longer
given, an “imaginary natural” status is represented by reference conditions. These reference
conditions, the potential natural status, are required for the field mapping and ensures the
comparability of the results. The reference conditions are defined with the help of the River
Type Region and the Morphological River Type (cf. freiland Umweltconsulting 2001).
All river type regions of Lower Austria and the morphological river types are described in
detail in the NÖMORPH Field Manual. The river type regions and morphological river types
concerning the surveyed sites for this work are illustrated in the Study Area section (see 5
Study Area).
River Type Region
For the typification rivers with a watershed area > 10km² are included. The standardization of
types, following abiotic criterias, includes several parameters for the zoning and the
characterization of the river type region:
-
Stream order (according to Strahler) at the mouth
Hydrological regime
Altitudinal belt of the headwaters and the mouth
Geology (coarse)
River landscape
Ecoregions according to Illies
The 9 River Type Regions of Lower Austria are (see Figure 2):
B
F
G
H
I
J
K
L
M
N
O
Water body of the Unglaciated Central Alps (Gewässer der unvergletscherten
Zentralalpen)
Water body of the South-Eastern Foreland (Gewässer des südöstlichen Vorlandes)
Waterbody of the Southern Vienna Basin (Gewässer des südlichen Wiener Beckens)
Water body of the North-Eastern Foothills of the Central Alps (Gewässer der
Nordostausläufer der Zentralalpen)
Water body of the Weinviertel and the Marchfeld (Gewässer des Weinviertels und
Marchfeldes)
Water body of the Northern Foreland (Gewässer des nördlichen Vorlandes)
Water body of the Granite- and Gneiss-Highlands (Gewässer des Granit- und
Gneishochlandes)
Water body of the Flysch- and Sandstone-Pre-Alps (Gewässer der Flysch- und
Sandsteinvoralpen)
Water body of the Limestone-Pre-Alps (Gewässer der Kalkvoralpen)
Water body of the high Limestone Alps (Gewässer der Kalkhochalpen)
Water body of the Grauwackenzone (Gewässer der Grauwackenzone)
On the basis of 5 summarizing parameters (channel geometry and flow characteristics,
riverbed, connectivity water - land, banks/acclivities, vegetation surroundings) the
characteristics of the 9 river type regions of Lower Austria are illustrated (see also 6
Reference Conditions and Results, freiland Umweltconsulting 2001).
43
4.2
Figure 2: The River Type Regions of Lower Austria.
(freiland Umweltconsulting 2001)
Morphological River Type
The morphological river type enables the characterization of a river stretch concerning the
dynamic restructuring processes of the riverbed and the environment (potential floodplain). It
is formed by the interaction of various abiotic parameters like geology of the watershed, bed
load, substrate ratios, runoff and so on.
Based on the natural channel geometry the mapped streams are assigned section by section
to a morphological river type (see Figure 4). When necessary, historical maps are used
because in Austria most rivers have been altered by human activities. The original channel
geometry is reconstructed with the help of the “Franziszeische Landesaufnahme” (land
surveying, 1806-1869, map scale 1:28.800). If this maps are missing maps from the
“Josephinische Landesaufnahme” (land surveying, 1764 bis 1785, map scale 1:28.800, see
Figure 3) are used instead (http://www.archivinformationssystem.at 2011). Additionally, the
valley form and the slope are included in this process if the river channel is heavily modified
(freiland Umweltconsulting 2001).
Figure 3: Example map “Josephinische Landesaufnahme”: Danube river between
Dobrohost and Bodiky downstream of Bratislava (1783-1784).
(http://www.gabcikovo.gov.sk 2011)
44
4.2
The morphological river type is also described with the help of the 5 summarizing parameters
(see also 6 Reference Conditions and Results).
stretched /constrained
- steep slope, mostly narrow valley form
- often sharp changes of direction
- the stream can oscillate locally by
sedimentations occur
what
alternating
braiding
- high bedload transport and a mean to steep slope lead to
numerous side channels
- no clearly defined banks
- often the whole valley bottom is influenced
- several subforms (e.g., braiding, anastomosing)
winding
-
transitional type between braiding and meandering
the channel already creates meander curves but is still locally
braiding creating islands
pendulous
- the valley bottom is wide enough for the stream to form inner
banks and outer banks
- the change of direction are mostly caused by valley sides,
alluvial fans, or terrace systems
- normally relative low bedload transport, slope too steep for
creation of meanders
meandering
- free meander develops in its own alluvion
- meanders in deep narrow valleys were formed by vertical
erosion
Figure 4: Morphological River Types.
(Jungwirth et al. 2003)
The reference conditions are determined before the field work begins because the surveyor
has to be familiar with them to be able to evaluate the morphological status.
Reference conditions are described for 5 summarizing parameters:
(see 6 Reference Conditions and Results)
-
Channel Geometry and Flow Characteristics: The original form of the channel is
researched with the help of
the “Franziszeische Landesaufnahme” or the
“Josephinische Landesaufnahme” (see Morphological river type and Figure 3). For
checking purposes the channel slope is contrasted with the valley form.
-
Riverbed: The substrate is determined using geological maps, the slope situation
and the valley form.
45
4.2
-
Connectivity Water - Land: Examination of the interactions between channel
geometry, valley form and substrate proportions.
-
Banks / Riparian Zone: The interactions between channel geometry, valley form,
substrate proportions and flow condition ( upper, middle, and lower course) are
described.
-
Vegetation: The following sources are used to investigate the potential natural
vegetation for the banks and for the vegetation of the adjacent area:
Die Pflanzengesellschaften Österreichs (Grabherr et al. 1993)
Wälder des Ostalpenraumes (Mayer 1974)
In the field the plausibility of the developed reference conditions is controlled and adapted if
necessary (freiland Umweltconsulting 2001).
46
4.2
4.2.1.2.2 General Characterization of the Assessed Parameters
(see Appendix B)
The first part of the field survey form includes general data and basic information of
the river stretch and its surroundings that are important for the orientation and the
assessment:
-
Name of the stream, bank (left or right), ID-number, film/photo number, name of
surveyor, date
-
River type (basis is the river type region), valley form (see Figure 5), altitudinal belt,
morphological river type, current water level, impact on flow conditions
-
Overview - characterization surroundings (rock, wood, forest, wetland, floodplain,
moor, grassland extensive, grassland intensive, agriculture, settlement area,
circulation area)
Valley plain
Gorge
-
no real valley form
channel running through ist own alluvion
-
profile is represented by vertical slopes and the river
bottom
river captures the whole valley bottom
V-shaped
valley
-
valley formed by water erosion, v-shaped profile
no real valley bottom or rather only local and narrow
combined forms possible, e.g., v-shaped valley incised in
u-shaped valley
-
slopes show clear characteristics of v-shaped valley
valley bottom present (Alluvion or glacial material)
-
definite differentiated wider valley bottom
slopes less steep
emerged from other valley form because of lateral
erosion or accumulation
Synclinal
valley
-
smooth transition from flat slopes to valley bottom
soft rock; areal washout plays an important role
often asymmetric valley profile
large alluvion not necessarily existent
U-shaped
valley
-
u-shaped profile form (just survives in solid rock)
soft rounded transition between valley bottom and
slopes; upper slopes get steeper again
glacial erosion form
V-shaped
valley with
narrow
bottom
Valley
with
distinctive
bottom
Figure 5: Valley Forms.
(Jungwirth et al. 2003, based on Wilhelmy 1990 and Mangelsdorf & Scheurmann 1980)
47
4.2
The second part of the field survey form is divided into a describing part
(characterization of summarizing parameters) and an evaluative part (evaluation of
summarizing parameters using single parameters, see Table 23).
Morphological and structural parameters that are mapped and evaluated concerning the
reference conditions in and along running waters are at the same time the 5 main sections of
the field survey forms (see Appendix B and Appendix C):
-
Channel Geometry and Flow Characteristics (characterization: current (see
4.2.2.4.2 Neutrally Buoyant Object Procedure), flow behaviour, evaluation: channel
geometry, flow pattern, dynamic component)
-
Riverbed (characterization: cross-section depth, depth variability, riverbed
stabilization, type of the riverbed stabilization, natural choriotopes (see Appendix B
for classes, size ranges, and description), evaluation: substrate-characteristic,
riverbed-relief, hyporheic interstitial)
-
Connectivity water - land (characterization: width-variability, shoreline stabilization,
type of shoreline stabilization (e.g., revetment), important woody debris
accumulations, important bed load accumulations, evaluation: connectivity,
structures)
-
Banks / Riparian Zone (characterization: cross-sections of the longitudinal course,
existence of dikes, riparian gradients, bank stabilizations (dimension, type), canopy
cover woods, shadowing of the water body, evaluation: bank/ acclivity characteristic,
species composition of vegetation, vegetation - layers and age)
-
Vegetation - including connectivity environment (characterization: total width of
woody riparian vegetation zone, canopy cover woods - environs, vegetation types
(surroundings, banks respectively acclivities), evaluation: buffer zone total, vegetation
species composition of environs, vegetation environs - layers and age)
4.2.1.3 Evaluation
When the evaluating part of the forms is filled out in the field, each of the 5 summarizing
parameters is assessed with the help of 4 main water body condition classes and 3
intermediate water body condition classes (see Appendix B for single parameters). Condition
class 1 stands for the best status, condition class 4 for the worst status. The condition class
for one summarizing parameter is calculated using the mean evaluation for the single
parameters (see Table 23).
Table 23: Example for the evaluation of a summarizing parameter.
SINGLE PARAMETER
Substrate-Characteristic
DESCRIPTION
typical, undisturbed
small scale alterations
definite homogenization
uniform, non-local material
EVALUATION
1
2
3
4
Riverbed-Relief
natural shape
local alterations
definite alterations
anthropogenic caused uniformity
1
2
3
4
48
4.2
Hyporheic Interstitial
unrestricted or naturally restricted
small scale restricted
existent just locally
restricted or rudimentary
1
2
3
4
(Location: Site 4/4, right bank. Summarizing parameter: Riverbed; Evaluation for single
parameters in bold letters; Result for condition class: 1-2)
The result is a 7-tier scale:
-
Condition class 1:
Condition class 1-2:
Condition class 2:
Condition class 3:
Condition class 4:
natural condition
natural - slightly modified condition
slightly modified condition
slightly modified - heavily modified condition
heavily modified condition
heavily modified - very heavily modified condition
very heavily modified condition
The total evaluation for the sample reach (point 6 on the form), which is the average of all 5
single summarizing parameters, is calculated when the field work is finished.
The condition classification of the NÖMORPH was transformed to the ecological status
classification and the corresponding colour code of the Water Framework Directive:
Table 24: Transformation scheme - NÖMORPH classification (7 classes) to the
classification of the WFD (5 classes).
Classes of NÖMORPH
1
1-2
2
2-3
3
3-4
4
Classes of Water Framework Directive
1
1
2
2
3
4
5
4.2.1.4 Used Forms
-
-
Main Form (two-sided)
(general data, overview – characterization surrounding area, channel geometry and
flow characteristics, riverbed, Connectivity water-land, banks respectively acclivities,
vegetation surroundings, overall evaluation, see Appendix C: Figure C-1 and Figure
C-2)
Additional Form 1: Structures interrupting the river continuum, point information (see
Appendix C: Figure C-3)
Additional Form 2: Backwaters, point information (see Appendix C: Figure C-4,
freiland Umweltconsulting 2001).
See Appendix C for forms and Appendix D for field work equipment.
49
4.2
4.2.2 Physical Habitat Characterization
The following sections concerning the characterization of the Physical Habitat
Characterization and its procedures have been extracted from Peck et al. (2006) and
from Kaufmann et al. (1999):
For this thesis 3 sections of the EMAP-W Field Operations Manual for Wadeable Streams
were executed in the field and analyzed:
-
Section 6: Stream Discharge (Philip R. Kaufmann)
Section 7: Physical Habitat Characterization (Philip R. Kaufmann)
Section 8: Invasive Riparian Plants (Paul L. Ringold, Teresa Magee, and Philip R.
Kaufmann)
4.2.2.1 Physical Habitat Components
Kaufmann assumes that there are 7 general physical habitat attributes essentially influencing
stream ecology (Kaufmann 1993):
-
Channel Gradient
Stream Size- Channel Dimension
The stream size is the major determining factor of habitat quantity in a stream. The general
size class of a stream, based on its watershed area, stream order or annual run-off, is
relatively stable. However, human alterations influence channel dimensions, floods, and low
flow discharges, hence changing the quantity and quality of aquatic habitat. Stream size
indicators measured in the course of the field survey are: thalweg depth, depth crosssections, wetted and bankfull width, and discharge.
Channel Gradient
The channel gradient influences water velocity, the potential energy in a stream, and bed
shear stress - characteristics that can be used to investigate the bedload transport capacity
and bed particle size that a stream can move under various flow conditions.
Channel Substrate and Type
The size of channel substrate, just as bedform (e.g., riffles and pools), influences the
hydraulic roughness and consequently the range of water velocities in a stream channel. In
addition, it has an effect on the size range of interstices that provide living space and cover
for macroinvertebrates, benthic fishes, and other organisms. Accumulations of fine substrate
particles reduce habitat space because they fill the interstices. In addition, they imped the
circulation of well oxygenated water.
The change of substrate size and its distributions is an indicator of upstream natural or
human catchment disturbances.
During the physical habitat characterization systematic substrate counts, visual assessments
of substrate embeddedness, and estimates of aquatic macrophyte and filamentous algal
cover are made.
50
4.2
As ecological interactions are complex, the quantification and evaluation of habitats and
cover is difficult. For the physical habitat characterization the following habitat components
were assessed: habitat type and distribution, large woody debris, in-channel cover for fish,
residual pools, channel complexity, hydraulic roughness, width variance, and bank sinuosity.
The riparian vegetation plays a major role in a river system because it influences the input of
nutrients, shading, channel structure, cover, large woody debris, wildlife corridors, buffer,
stream temperature, and bank stability.
The EMAP-W method recommends to use the measurements of a canopy densiometer to
evaluate channel shading.
Near- channel and riparian human alterations and disturbances like settlements and land use
(e.g., buildings, lawns, roads, pastures, orchards, and row crops) are distinguished from inchannel human activities and disturbances including channel revetment, pipes, straightening,
bridges, culverts, and trash. These human influences serve as habitat quality indicators and
diagnostic indicators of anthropogenic stress.
The channel-riparian interaction of rivers is often disordered or nearly absent because of
human alterations and activities. Concerning the quantification of this interaction the physical
habitat characterization uses measurements of channel sinuosity, channel incision, and
channel morphometric complexity (based on the spatial pattern and variability in channel
width and depth profile data, cf. Kaufmann et al. 1999).
4.2.2.2 Procedure of Physical Habitat Characterization
Although several field surveys on streams can be executed the whole year, the best time for
physical habitat characterization would be a low flow season after leaf out and not closely
following major flood events.
Surveyed stretches are chosen with the help of the „blue line stream“ – network, United
States Geological Survey – maps on a scale of 1:100,000. For the better orientation in the
field the location of the sampling point is marked with an X on 1:24,000-scale maps. As the
coordinates for the predetermined midpoints of the chosen reaches (X-sites) are on the site
information sheets in a dossier compiled for each sampling site, it is also possible to use a
GPS-receiver to find preselected survey sites in the field (Peck et al.2006).
As local habitat create typical repeating patterns of variation (e.g., riffle-pool structure,
meandering morphology), sample reaches should be 40 times their low flow wetted width (at
the time of sampling), but never less than 150m long to incorporate the local habitat-scale
variation (e.g., pools, riffles, meanders, etc.).
The method is designed in such a way that a trained crew of two is able to survey a
wadeable river stretch, regardless of whether it is broader than 10m and complex, within 4.5
hours. While one person makes the measurements in the channel, the other person records
these measurements and does the visuals estimations and counts for the channel and its
surroundings.
The surveyors measure upstream and downstream the distance of 20 times the wetted width
from a X-site to define the length of a sample reach. Furthermore, 11 transect positions are
set and flagged at 1/10th of the sample reach length, or four times the mean wetted channel
width apart.
The survey starts with the measurements and estimations at the first cross-section at the
downstream end of the sampling reach, transect A, and follows the river upstream to transect
K (see Figure 6).
51
4.2
Intermittent, ephemeral or dry streams
Even if a stream or a stretch is intermittent or ephemeral all assessable data should be
collected. This is important in order to characterize available aquatic habitat space and
quantify changes over time that might result from such influences as climate change and
irrigation withdrawal (cf. Kaufmann et al. 1999).
The Physical Habitat Characterization method consists of 5 main components to
assess the 7 general physical habitat attributes mentioned above:
- Thalweg Profile
- Woody Debris Tally
- Channel and Riparian Characterization ( including Invasive Riparian Plants)
- Assessment of Channel Constraint, Debris Torrents, and Major Floods
- Discharge
4.2.2.2.1 Thalweg Profile
Thalweg refers to the flow path of the deepest water in a stream channel.
After the measurements and estimations at transect A are finished (see Appendix C for
forms), the field crew starts at station 0 (equals transect A) and walks up the reach making
measurements of the maximum depth, classifying habitat (see Appendix B for channel unit
codes) and pool-forming features (see Appendix B for pool form codes), and checking the
presence of off-channel habitats (e.g., backwater pools, sloughs, alcoves), side channels and
loose, soft deposits of sediment particles (≤ 16mm diameter) at 10-15 equally spaced
intervals (100 or 150 individual measurements along the entire reach – increments
depending on the average wetted width) between each of 11 channel cross-section transects
(A to K).
In order for a channel habitat unit to be distinguished, it must be at least as wide or long as
the channel is wide (except for off channel backwater pools, which are noted as present
regardless of size).
Additionally, wetted width is measured and substrate particle size classes are evaluated at
the 11 regular channel cross-section transects and at 10 supplemental cross-sections
midway between them (21 width measurements and substrate cross-sections). The location
and estimation of the size class of the substrate particles (see Appendix B for substrate size
class codes) are carried out on the left channel margin and at positions 25%, 50%, 75%, and
100% of the distance across the wetted channel (see Figure 6 and Appendix C).
Determination of increments between thalweg profile measurements:
▪ Channel width < 2.5m → increment = 1.0m (150 measurements)
▪ Channel width 2.5 to 3.5 m → increment = 1.5m (100 measurements)
▪ Channel width > 3.5 m → increment = 0.01 x (support reach length), (100 measurements)
52
4.2
Figure 6: Support reach layout for physical habitat measurements (plan view).
(Peck et al. 2006)
4.2.2.2.2 Large Woody Debris Tally
Large Woody Debris numbers within and above the bankfull channel according to specified
length and diameter classes are tallied between each of the channel cross sections parallel
to the Thalweg Profile measurements (10 separate tallies; see Figure 6 and Appendix C).
Large woody debris is defined as woody material with a small end diameter of at least 10cm
and a length of at least 1.5m. The length and both end diameters are visually estimated in
order to place a large woody debris in one of the twelve diameter and length categories (see
Appendix B). The tally includes only pieces of large woody debris that are at least partially in
the baseflow channel (Zone 1), in the active channel (Zone 2, flood channel up to bankfull
stage), or spanning above the active channel (Zone 3) (see Figure 7). The active (or bankfull)
channel is defined as the channel that is filled by moderate sized flood events that typically
recur every one to two years.
53
4.2
Figure 7: Large Woody Debris influence zones.
(Peck et al. 2006, modified from Robison and Beschta 1990)
Each time the crew reaches a new cross-section transect, it does the Channel and Riparian
Characterization measurements and estimations of this cross-section before it starts filling
out a new copy of the Thalweg Profile and Woody Debris Form (Peck et al. 2006).
4.2.2.2.3 Channel and Riparian Characterization
At all 11 cross-section transects placed at equal intervals along the reach length the following
measurements, estimations, and observations are carried out (preferably in the presented
order, see Figure 6, Appendix B, and Appendix C):
•
Channel Cross Section Dimensions, Substrate Size Class and Embeddedness
(see Figure 8)
First, the Wetted Width is measured (if the cross-section is dry, measurements across the
unvegetated part of the channel are made).
Then the substrate sampling points are located at 0, 25, 50, 75, and 100 percent of the
wetted width, even if the channel is split by a mid-channel bar and a sample point is not
under water. At each of the sample points the depth is measured and the Substrate Size
Class code is recorded.
The Substrate Embeddedness, as percentage of the surface embedded, is estimated in a
10cm diameter circle around the rod of the surveyor.
In addition to the wetted width, the width of exposed mid-channel Bars of gravel or sand is
recorded.
54
4.2
Figure 8: Substrate sampling cross-section.
(Peck et al. 2006)
•
Bank Morphology
Bank Angle and Bank Undercut Distance are quantified on both banks (see Figure 9). The
angle is determined with a clinometer laying on a short pole (approximately 1m long) resting
on the ground for about 0.5m. The undercut distance should be at least 0.5m.
Figure 9: Determining bank angle under different types of bank conditions.
(A) typical, (B) incised channel, (C) undercut bank, (D) overhanging bank (Peck et al. 2006).
55
4.2
Bankfull Height is measured up from the level of the wetted edge of the stream (see Figure
10 and Figure 11).
The bankfull height is determined by the bankfull flow which occurs every 1 to 2 years and
erodes the riverbed and banks by what it also influences the width and depth of a channel.
The bankfull flow level can be estimated with the help of several indicators:
-
Obvious breaks in the slope of the banks
Changes from water-loving and scour-tolerant vegetation to more drought-tolerant
vegetation
Changes from well-sorted stream sediments to unsorted soil materials
drift debris
Level where deciduous leaf-fall is absent on the ground
Unvegetated sand, gravel or mud deposits from previous year’s flooding
Incision Height is the vertical distance from the wetted edge to the level of the first terrace
above the bankfull height (see Figure 10 and Figure 11). The bankfull channel height and the
incision height can be the same, if there is no great incision, but bankfull height is never
greater than the incision height. It is important to observe both banks to determine incision
height and bankfull height accurately. If the terraces do not have the same height, the lower
terrace is chosen. For this thesis incision was measured with a TruPulse 360°B Laser
Rangefinder.
Figure 10: Determining bankfull and incision heights for (A) deeply incised channels,
and (B) streams in deep V-shaped valleys.
(Stick figure included for scale, Peck et al. 2006)
56
4.2
Figure 11: Schematic showing relationship between bankfull channel and incision.
(A) not recently incised, and (B) recently incised into valley bottom. Note level of bankfull
stage relative to elevation of first terrace (abandoned floodplain) on valley bottom. (Stick
figure included for scale, Peck et al. 2006).
•
Canopy Cover Measurements
Canopy cover measurements are made with a spherical densiometer
(model A - convex type) in each of four directions at the center of the
stream - to estimate canopy cover over the channel - and one on each
bank at the wetted channel margins - to estimate cover of the riparian
zone.
Figure 12: Example of a Spherical Densiometer.
(http://www.dynamicaqua.com 2011)
The densiometer is marked with a marker or a tape to limit the number of square grid
intersections so that the readings can range from 0 (no canopy cover) to 17 (maximum
canopy cover, see Figure 13).
In the field, the densiometer measurements are taken at 0.3m above the water surface using
the bubble level. The 17 points of grid intersection within the taped “V” are observed if they
are overlain by vegetation and the number of those covered is recorded.
57
4.2
Figure 13: Schematic of modified convex spherical canopy densiometer.
10 of the 17 intersection points are covered by vegetation (Peck et al. 2006, from Mulvey et
al. 1992).
•
Areal Cover of Fish Concealment Features, Aquatic Macrophytes and
Filamentous Algae
This semi-quantitative evaluation uses the visual estimation of the areal cover of the fish
cover and other features in the water and on the banks 5m upstream and downstream of the
cross-section (see Figure 14 and Appendix B.):
-
Filamentous Algae
Aquatic Macrophytes ( including mosses and in-stream live wetland grasses)
Woody Debris ( >0.3m, possibly affecting stream morphology)
Brush/Woody Debris ( <0,3m, not affecting stream morphology)
Live Trees/Roots (under water)
Overhanging Vegetation ( within 1m of the surface)
Undercut Banks
Boulders (basketball- to car-sized)
Artificial Structures (all non-natural structures including channel stabilization, trash
etc.)
For the evaluation areal cover classes are used:
0 = Absent (0%)
1 = Sparse (<10%)
2 = Moderate (10-40%)
3 = Heavy (40-75%)
4 = Very heavy (>75%)
58
4.2
Figure 14: Riparian zone and instream fish cover plots for a stream cross-section
transect.
(Peck et al. 2006)
•
Riparian Vegetation Structure
The Visual Riparian Estimation is a semi-quantitative method to determine the cover class
and type (deciduous, coniferous, broadleaf evergreen, mixed, absent) of riparian vegetation
(e.g., trees, shrubs, grasses, etc.) in canopy, mid-layer and ground cover, using the same
areal cover classes as the fish cover method.
The area observed is an estimated 10m x 10m riparian plot (defined as if projected down
from an aerial view) on both banks (see Appendix B and Appendix C).
The calculation of the obtained data provides information on the health and the level of
disturbance of the stream corridor as well as on the present and future potential for various
types of organic inputs and shading.
59
4.2
•
Human Influences and Disturbances
11 categories of Human Influences are examined concerning their presence or absence with
the help of four proximity classes (not present, >10 away/outside of the riparian plot, within
the riparian plot, on the bank/ in the stream; see Figure 14 and Appendix B):
-
Walls, dikes, revetments, riprap, dams
Buildings
Pavements, cleared lots
Road, railroads
Pipes (inlet/outlet)
Landfill, trash
Parks, lawns
Row crops
Pastures, ranges, hay fields
Logging operations
Mining activities
An influence is recorded as present at every cross-section where it can be seen.
•
Riparian “Legacy” Trees
The Riparian “Legacy” Tree procedure is used to get an impression of possible historic
vegetation conditions and the potential for the riparian tree growth. For this, the largest tree
between a transect and the next transect upstream is located ( the tree must not necessarily
be an old “legacy” tree). After the type is recorded, the height, the diameter at breast height
and the distance from the wetted margin of the stream are estimated (see Appendix C). At
transect K, the surveyor looks upstream a distance of 4 channel widths to identify the
“legacy” tree.
•
Slope and Compass Bearing
The Slope of a river has different functions:
-
It is an indicator of potential water velocities and stream power.
It provides information concerning habitat complexity because of its variability that
influences water velocities, water depths and sediment sizes.
It is used to compute residual pool depths, volumes, and numbers.
It is necessary for calculating relative bed stability.
Compass Bearing together with the distance between transects is used to estimate the
sinuosity of a channel which is the ratio of the length of the reach divided by the straight line
distance between the two reach ends.
The water surface slope and bearing are measured by “backsighting” with a clinometer and a
compass downstream between each cross-section walking upstream or in reverse order
downstream (after the Thalweg, channel and riparian measurements).
It can happen that the surveyor cannot measure directly from one transect to the other
because of heavy thicket, sharp slope breaks or tight meander bends. Then it is necessary
to carry out supplemental slope and bearing measurements that are always located
upstream of the main observation. In addition, it is important to estimate the proportion of the
stream segment between transects included in each supplemental measurement (see Figure
15, Appendix B, and Appendix C ).
60
4.2
Figure 15: Water surface slope and bearing measurements.
(Peck et al. 2006)
Side Channels
If the estimated flow in a side channel is less than or equal to 15% of the total flow, its
presence is flagged on the thalweg profile form but no measurements are made. If an island
creates a major side channel with more than 15% of the total flow, an additional crosssection is determined and separate substrate, bank and riparian measurements and
estimations are made and written down on a separate cross-section form. No Thalweg or
other data are quantified for a side channel. Riparian plots established on the island for each
transect may overlap if the island is less than 10m wide at the transect (see Figure 16).
61
4.2
Figure 16: Riparian and instream fish cover plots for streams with minor and major
side channels.
(Peck et al. 2006)
4.2.2.2.4 Assessment of Channel Constraint, Debris Torrents, and Major Floods
After Thalweg and transect measurements and estimations are completed further
observations are made (see Appendix B and Appendix C):
The Channel Pattern is determined with the help of 3 classes (one can be chosen):
-
One channel (predominant single channel or a dominant main channel)
Anastomosing channel (major and minor channels, vegetated islands above bankfull
flow)
Braided channel (often no obvious dominant channel, unvegetated bars below
bankfull flow)
62
4.2
Description of the Channel Constraint (one can be chosen):
-
Channel is very constraint in V-shaped valley
Channel is in broad valley but constrained by incision
Channel is in narrow valley but is not very constrained
Channel is unconstrained in broad valley
For the identification of Constraining Features the surveyor has to chose one of several
alternatives: bedrock, hillslope, terrace, human bank alterations, no constraining features).
The percentage of the Channel Margin that is constrained is estimated for the whole sample
reach. The “Typical” Bankfull Width and the average Width of the Valley Floor is also
estimated.
Debris Torrents and Major Floods can change habitat and biota and thereby influence the
interpretation of measurements. Debris torrents are flood waves of high magnitude and short
duration, with a flow consisting of a dense mixture of water and debris.
In the field evidence of recent major floods and torrents is investigated by examining the
entire sample reach for torrent scouring and torrent deposits (locations where the motion of a
torrent stops and large amounts of sediment, boulders, logs, etc. are deposited) (Peck et al.
2006).
4.2.2.3 Invasive Riparian Plants
At the same time the measurements of the channel and the estimations of the surroundings
are executed at the eleven cross-sections, the 10m x 10m riparian plots on both banks are
examined for the presence of species of invasive plants (see Figure 14). The EMAP-W
presents twelve selected species as target species which are described in detail in Appendix
D of the EMAP-W Field Operations Manual for Wadeable Streams. The basis of this
selection were the ease of field identification by non-botanists, degree of economic or
ecological impact at a regional scale, preference for riparian habitats, lack of toxicity, and
variety within the list of target species. Different combinations of the twelve species were
developed for each individual state, so that the list of target plant taxa varies from state to
state (the presence of other invasive species not on the list is noted in the comment section
of the form - see Appendix C).
The selected species are:
Common burdock (Arctium minus)
Giant Reed (Arundo donax)
Cheatgrass (Bromus tectorum)
Musk Thistle (Carduus nutans)
Canada Thistle (Cirsium arvense)
Teasel (Dipsacus fullonum)
Russian-olive (Elaeagnus angustifolia)
Leafy Spurge (Euphorbia esula)
English Ivy (Hedera helix)
Reed Canarygrass (Phalaris arundinacea)
Himalayan Blackberry (Rubus armeniacus)
Salt Cedar (Tamarix spp.)
63
4.2
(Peck et al. 2006).
As these species are not invasive or even native in Austria, they were not included in the
field work and evaluation for this thesis. Instead the focus are riparian invasive alien plants in
Austria.
4.2.2.4 Stream Discharge
Stream discharge is equal to the product of the mean current velocity and vertical cross
sectional area of flowing water.
The stream discharge measurements are done after the other measurements and
estimations are finished. As no single method for measuring discharge is applicable to all
types of stream channels, EMAP-W published several procedures and activities providing
either the measurement data to calculate discharge or the calculated value for stream
discharge ( see Stream Discharge Form Appendix C).
4.2.2.4.1 Velocity-Area Procedure
The velocity-area procedure is implemented at one carefully chosen channel cross-section
within the sample reach that is as much like a canal as possible, preferably free of
obstructions. If necessary, rocks, woody debris et cetera should be removed. The flow
should be relatively uniform, with no eddies, backwaters, or excessive turbulence and depth
should mostly be greater than 15 cm, velocities mostly greater than 0.15 m/s.
The total wetted width of the cross-section is divided into 15 to 20 equal-sized intervals that
should not be less than 10 cm wide, even if this results in less than 15 intervals.
At each interval point the flow cross-sectional area and the velocity - with an electromagnetic
current meter or an impeller-type meter at 0.6 of the measured depth below the surface of
the water - are measured (see Figure 17). Each increment gives a subtotal of the stream
discharge, and the whole is calculated as the sum of these parts.
Figure 17: Layout of a channel cross-section for obtaining discharge data by the
velocity-area procedure.
(Peck et al. 2006)
64
4.2
4.2.2.4.2 Neutrally Buoyant Object Procedure
The required information are the mean flow velocity in the channel and the cross-sectional
area of the flow. This procedure is used in very small and shallow streams where a
measured segment of the sampling reach that is uniform and deep enough to float a neutrally
buoyant object freely is selected. Examples of suitable objects include small oranges, small
sponge rubber balls, or small sticks.
The channel cross-sectional area is determined with the help of depth measurements at 5
equally spaced points at one to three channel cross-sections, depending on the width
variance, within the measured segment. Then the time that the object needs to pass through
the segment is measured three times to calculate the mean time afterwards.
4.2.2.4.3 Timed Filling Procedure
In streams that are too shallow for the current velocity probe to be placed in the water, or
where the channel is broken up or irregular due to rocks and debris, and a suitable crosssection for using the velocity area procedure is not available, discharge can also be
determined directly by measuring the time it takes to fill a container of known volume.
First, a cross-section of the stream that contains one or more natural spillways or plunges
that collectively include the entire stream flow is chosen. If such a cross-section does not
exist, a temporary spillway using on-site materials can be constructed, or a portable weir
using a plastic sheet and on-site materials can be installed. Beneath the spillway a calibrated
container is positioned to capture the entire flow.
Then the time (in seconds) required to collect a known volume of water (in liters) is
determined using a stopwatch 5 times for each spillway that occurs in the cross-section.
4.2.2.4.4 Direct Determination of Discharge
The velocity-area procedure, the neutrally buoyant object procedure, and the timed filling
procedure provide data from which discharge (Q) is calculated by computer later. Some
current velocity meters have the capability to calculate discharge in the field immediately
after taking all of the measurements (Peck et al. 2006).
65
4.2
4.2.2.5 Evaluation
The result of the field work is an extensive amount of data that can be used for a multitude of
calculations and evaluations. As the aim of this thesis is the comparison and analysis of
methods assessing hydromorphology with regard to the European Water Framework
Directive, only calculations relevant in this context have been performed. Furthermore, some
evaluations have been excluded due to the lack of necessary biological data (e.g., data on
macroinvertebrates and fish).
Consequently, the following parameters have been calculated in the scope of this work (see
also section 6 Reference Conditions and Results, Kaufmann et al. 1999):
4.2.2.5.1 Habitat Characteristics
•
Channel Morphology Statistical Summaries
Channel dimension measurements were reduced to whole-reach habitat characterizations by
calculating their means. Because the data are systematically spaced, these averages are
estimates of the spatial distributions of the habitat characteristics measured.
-
Mean Wetted Width (m)
Mean Bankfull Width (m)
Mean Bankfull Height (m)
Mean Incision Height (m)
Mean Thalweg Depth (cm)
Mean Bank Angle - Left (°)
Mean Bank Angle - Right (°)
Mean Undercut Distance Left (m)
Mean Undercut Distance Right (m)
Mean Bar Width (m)
Mean Substrate Diameter (cm)
Mean Substrate Embeddedness (%)
Slope Total (%)
Mean Slope between transects (m)
Mean Canopy Cover left (%)
Mean Canopy Cover right (%)
•
Discharge and Flow Velocity
To calculate the discharge, the following calculations were executed:
Discharge (m³s−1) = Velocity x Cross-sectional area
The Flow Velocity (ms−1) within a reach was estimated using the Neutrally Buoyant Object
Procedure (see also 4.2.2.4.2 Neutrally Buoyant Object Procedure). Because of the
proportion of the surface velocity to the velocity of the whole water body, the estimated
velocity was reduced by the factor 0.85 with regard to the NÖMORPH method.
66
4.2
Then the Cross-sectional area was calculated:
Cross-sectional area (m²): A= [d1 x (w1+w2) + d2 x (w2 + w3) + d3 x (w3 + w4) + d4 x (w4+
w5) + d5 x (w5 + w6)] / 2
Figure 18: Sketch of a cross-section
The sketch illustrates width (w) and depth (d) measurements for the cross-sectional area.
•
Substrate Size and Composition
Substrate Classes
The systematic pebble counts were directly reduced to whole-reach substrate
characterizations by calculating percentages of observations within stated size classes.
Because the data are systematically spaced, these averages and percentiles are interpreted
as unbiased representations of the substrate characteristics measured.
Mean Substrate Diameter
The following algorithm for calculating the geometric mean substrate diameter (Dgm) was
used:
Essentially, to each particle a nominal diameter equal to the geometric mean of its upper and
lower bounds is assigned (i.e., the upper and lower bounds are log transformed and divided
by two). This is simplified by using the frequency-weighted class-midpoints as follows:
Dgm = Antilog of Sumi { Pi {[log10 (Diu) + Log10(Dil )]/2} }
Where:
Pi = Proportion of particle count within diameter class i (i.e., Frequency within
diameter class i / total number of particles in pebble count)
Diu = Diameter (mm) at upper limit of diameter class i
Dil = Diameter (mm) at lower limit of diameter class i
Sumi = Summation across diameter classes
The nominal size class midpoint diameters of 5660mm and 0.0077mm, respectively for the
largest and smallest (unbounded) diameter classes result from assigning an upper (nominal)
range value of 8000mm for bedrock and hardpan, and a (nominal) lower range diameter of
0.001 mm for "fines".
Wood, Organic Matter, and RC categories are excluded from the diameter calculation.
67
4.2
•
Slope
Slope measurements were carried out with the help of the TruPulse 360°B Laser
Rangefinder. As the tool does not measure vertical distance exactly to the centimeter, for the
estimations an interval of 5 centimeters was used.
•
Sinuosity
Sinuosity is measured as the distance along the channel “as the fish swims” divided by the
direct line-of-site distance “as the crow flies” up the valley between the two ends of the reach.
Running waters that flow directly downslope have a sinuosity index of 1, the more sinuous
the course of a river is the higher is the index.
Sinuosity = (Reach length) ÷ (“Crows” distance)
= [Σ(DT)] ÷ [(Σ“Northing”)2 + (Σ“Easting”)2]½
=
Σ DT
√ (Σ DT cos θ)² + (Σ DT sin θ)²
Where:
“Northing” and “Easting” are, respectively, the northern and eastern vector
components of the distance from the downstream starting point.
DT = Distance along channel between transects,
Σ = summation over transects,
θ = compass bearing in radians= 2π(degrees of bearing/360 degrees - for this thesis
400 degrees were used for the calculation as the compass was divided in gon).
•
Canopy Cover was visually estimated because a densiometer was not available. Estimations
were carried out for the left bank and the right bank at each transect at the mid-channel.
•
Large Woody Debris
For the calculation of the characteristic volume of each LWD class (see Appendix B) the
formula is:
Volume = pi * [(minDiam+(maxDiam-minDiam)/3)/2]² * [minLength+(maxLengthminLength/3)]
where the extra large diameter class maxes out at 2m, and the long length maxes out at 30
m.
68
4.2
The volumes from the formula as applied to each of the tallys in the diameter-length class
matrix are:
v1w=(rchwsdsl*0.058) + (rchwsdml*0.182) + (rchwsdll*0.436) +
(rchwmdsl*0.335) + (rchwmdml*1.047) + (rchwmdll*2.513) +
(rchwldsl*0.931) + (rchwldml*2.909) + (rchwldll*6.981) +
(rchwxdsl*3.016) + (rchwxdml*9.425) + (rchwxdll*22.62)
The variables like rchwsdsl are the reachwide tallys of the number of pieces in a particular
size class (in this case small diameter, small length).
Abbreviations:
sdsl: small diameter-small length; sdml: small diameter-medium length; sdll: small diameterlarge length; mdsl: medium diameter-small length; mdml: medium diameter-medium length;
mdll: medium diameter-large length; ldsl: large diameter-small length; ldml: large diametermedium length; ldll: large diameter-large length; xdsl: extra large diameter-small length;
xdml: extra large diameter-medium length; xdll: extra large diameter-large length.
For each reach volume calculations were executed for LWD all/part in bankfull channel (m³)
and LWD above bankfull channel (m³).
•
Habitat Classes
Habitat class data were used to calculate reach level percentages of each class (e.g., the
percentage of the reach length classified as plunge pool habitat).
•
Fish Cover
Field data estimating the presence and cover of fish concealment features consists of visual
estimates of the cover class category of eight specific types of features in 11 observation
plots distributed along each stream sample reach. The metric summaries calculated are
whole-reach averages, based on cover or presence estimates at 11 stations.
For each fish concealment type, the areal cover in four classes was estimated: absent (0),
sparse (0 to 10%), moderate (10 to 40%), heavy (40 to 75%) and very heavy (> 75%). Reach
fish cover metrics were then calculated by assigning cover class midpoint values (i.e., 0%,
5%, 25%, 57.5%, and 87.5%) to each plot’s observations and then averaging those cover
values across all 11 stations.
4.2.2.5.2 Riparian Vegetation Cover and Structure
Reach riparian cover metrics were calculated by assigning the cover class mid-point value,
as described for fish cover, to each riparian plot’s observations and then averaging those
cover values across all 11 stations, separately for the three cover layers (canopy, understory,
and ground cover) as well as for left and right banks. In addition, estimated percentages of
the reach riparian area with canopy and midlayer comprised of deciduous, coniferous,
broadleaf evergreen, or mixed vegetation types were calculated.
69
4.2
4.2.2.5.3 Human Disturbances and Influences
The presence and proximity of 11 predefined types of human land use or disturbance based
on 22 separate visual observations were recorded at both the left and right sides of the
channel at 11 transect locations. Observations were specified in three proximity categories:
“B” within the channel or on the stream bank, “C” within the 10 m × 10 m riparian sample
plots, and “P” behind or adjacent to the plots. Each observation was weighted according to
its proximity to the stream: Weightings were 1.5 for disturbance observations within the
channel or on the stream bank (“B”), 1.0 for observations within the 10 m × 10 m riparian
sample plots (“C”), and 0.667 for those behind or adjacent to the plots (“P”). Metric
summaries were calculated to get average whole-reach weightings for every type of human
land use or disturbance.
4.2.2.6 Used Forms
(Peck et al. 2006)
-
Channel/Riparian Cross-section Form (see Appendix C: Figure C-5)
Thalweg Profile and Woody Debris Form (see Appendix C: Figure C-6)
Riparian “Legacy” Tree and Invasive Alien Plants Form (see Appendix C: Figure C-7
and Figure C-8)
Slope and Bearing Form (see Appendix C: Figure C-9)
Stream Discharge Form (see Appendix C: Figure C-10)
Channel Constraint and Field Chemistry Form (see Appendix C: Figure C-11)
Torrent Evidence Assessment Form (see Appendix C: Figure C-12)
See Appendix D for field work equipment.
70
4.3
Comparison NÖMORPH - Physical Habitat Characterization
4.3
The NÖMORPH method and the Physical Habitat Characterization are both used to assess
three primary zones of running waters: channel, riparian zone, and surroundings.
The task of the qualitative Austrian method is the description and the visual evaluation of the
present hydromorphological status. This evaluation is based on the assignment of predefined
parameters to condition classes (see 4.2.1.3 Evaluation). The American Physical Habitat
Characterization is a mainly quantitative assessment method for site classification and trend
interpretation including various measurements and calculations.
4.3.1 Goals of the Surveys
NÖMORPH
- Goal: The NÖMORPH method (cf. freiland Umweltconsulting 2001) analyzes the deviation
of the current status from the natural and characteristic status - the target state which is
represented by reference conditions.
- Reference condition: Reference conditions or the potential natural status are derived from
the river type region, the morphological river type, as well as the morphology and the
vegetation of river, banks, and surroundings using information of historical maps if
necessary.
Field of application:
-
First report and basis for evaluation of aquatic ecology aspects in the course of water
management projects.
Planning principles for projects improving the ecological functionality, determination of
the worthiness of protection of running waters, documentation of changes, etc..
Illustration of correlations between structural water body condition and biological
water quality.
Physical Habitat Characterization
- Goal: The Physical Habitat Characterization is a predominantly quantitative method for the
assessment of physical habitat in streams. It focuses as much as possible on direct
measures of physical properties of running waters that are most likely to have effects on
biological communities respectively on the assessment of the relative importance of potential
stressors on those communities.
- Reference condition: Because of the difficulty of estimating historical conditions for many
indicators, least disturbed sites serve as reference sites.
Field of application:
-
Report on the ecological conditions of streams and rivers.
Identification and ranking of the relative importance of physical and biological
disturbances affecting stream and river conditions.
The data from the habitat characterizations were used to describe the ecological conditions
of western streams and rivers and to calculate the summary indicators of physical habitat
quality in the national assessments.
Furthermore, combined data analyses (e.g., field-based physical habitat measurements,
water chemistry, temperature, and remote imagery of basin land use and land cover) were
71
4.3
carried out to illustrate additional habitat attributes and larger scales of physical habitat or
human disturbance (cf. Stoddard et al. 2005).
“The Wadeable Streams Assessment (WSA) utilized data from EMAP-W and is now
combined with a second continuative national survey of streams: the National Rivers and
Streams Assessment (NRSA). Data are now being validated and analyzed, and the final
NRSA report is expected in 2012” (USEPA 2011).
4.3.2 Mapped and Evaluated Criteria and Parameters
NÖMORPH
The NÖMORPH method describes hydromorphological attributes and evaluates predefined
single parameters with the help of status classes (for attributes and parameters see
Appendix B). These attributes and parameters are assigned to 5 “summarizing parameters”.
Based on these 5 “summarizing parameters” the ecomorphological status of a river section is
assessed with regard to the reference conditions (cf. freiland Umweltconsulting 2001):
-
Channel geometry and flow characteristics
Riverbed
Connectivity water - land
Banks respectively Riparian Zone
Vegetation
Spatial scale / Reach length:
The field work and the assessment is carried out using maps at a scale of 1:25,000 (ÖK 25).
A river is surveyed from mouth to source, as soon as one of the parameters changes
(irrespective of the change of the numerical value of this parameter), a new sample reach
begins. Again, all 5 summarizing parameters are assessed and estimated with the help of
new forms. A river stretch has to be at least 100m long. Left and right banks are surveyed
and assessed separately so that a stretch can be longer or shorter than the opposite stretch.
7 general physical habitat attributes (for individual parameters see Appendix B) are
measured and estimated during the Physical Habitat Characterization procedure (cf.
Kaufmann et al. 1999):
-
Channel Gradient
Spatial scale / Reach length:
Surveyed stretches are chosen with the help of the „blue line stream“ – network, United
States Geological Survey – maps on a scale of 1:100,000. For the better orientation in the
field the location of the sampled reaches is marked with an X on 1:24,000-scale maps.
72
4.3
The length of sample reaches should be 40 times their low flow wetted width (at the time of
sampling), but never less than 150m long to incorporate the local habitat-scale variation
(e.g.,pools, riffles, meanders, etc.).
Detailed measurements and estimations are carried out at 11 transect positions that are set
and flagged at 1/10th of the sample reach length, or four times the mean wetted channel
width apart. Left and right banks are surveyed separately (cf. Peck et al. 2006).
4.3.3 Field Work
NÖMORPH
The mapping, that can be carried out by one experienced person, is executed during
“normal” or low flow conditions. In the field the plausibility of the developed reference
conditions is controlled and adapted if necessary.
The field survey starts with the documentation of general data and basic information of the
river stretch and its surroundings that are important for the orientation and the following
assessment.
The second part of the field survey is divided into a describing part (characterization of
summarizing parameters) and an evaluating part (evaluation of summarizing parameters
using single parameters, see Table 23, cf. freiland Umweltconsulting 2001).
The best time for physical habitat characterization is a low flow season after leaf out and not
closely following major flood events. The method is designed in such a way that a trained
crew of two is able to survey a wadeable river stretch, regardless of whether it is broader
than 10m and complex, within 4.5 hours. While one person makes the measurements in the
channel, the other person records these measurements and does the visuals estimations
and counts for the channel and its surroundings.
The survey starts with the measurements and estimations at the first cross-section at the
downstream end of the sampling reach, transect A, and follows the river upstream to transect
K including measurements between the transects (see Figure 6, cf. Kaufmann et al. 1999).
4.3.4 Evaluation
NÖMORPH
Each of the 5 single summarizing parameters is evaluated with the help of 4 main water body
condition classes and 3 intermediate condition classes. Condition class 1 stands for the best
status, condition class 4 for the worst status. The condition class for one summarizing
parameter is calculated using the mean evaluation for the single parameters (see Table 23).
The aggregated condition of a reach is the average of the condition of all 5 single
summarizing parameters (cf. freiland Umweltconsulting 2001).
Condition classes:
-
Condition class 1:
Condition class 2:
Condition class 3:
natural condition
natural - slightly modified condition
slightly modified condition
slightly modified - heavily modified condition
heavily modified condition
heavily modified - very heavily modified condition
73
4.3
-
Condition class 4:
very heavily modified condition
The condition classification of the NÖMORPH was transformed to the ecological status
classification and the corresponding colour code of the Water Framework Directive (see
Table 24).
Acquired data can be used for a multitude of calculations and evaluations (see 4.2.2 Physical
Habitat Characterization, 6 Reference Conditions and Results, and 3.3.3 Environmental
Monitoring and Assessment Program Western Pilot Study).
EMAP-W used chemical, physical and biological indicators to measure the stress to which
streams and rivers are exposed. Concerning physical habitat the focus was on four specific
stressors of physical habitat (streambed stability, habitat complexity, riparian vegetation, and
riparian disturbance) and how they indicate levels of stress on aquatic organisms (relative
extent and relative risk of stressors, cf. Stoddard et al. 2005).
Qualitative Physical Habitat Index (QTHP)
Hughes et al. (2010) executed and discussed four physical habitat indexes including the
Stream Visual Assessment Protocol (SVAP) Version 2 of the Natural Resources
Conservation Service, the Qualitative Habitat Evaluation Index (QHEI) of the Ohio
Environmental Protection Agency, the Rapid Bioassessment Protocol (RBP) of the United
States Environmental Protection Agency (USEPA), and a Qualitative Physical Habitat Index
(QTHP) based on USEPA quantitative physical habitat measurements as applied for this
work.
The QTPH is a qualitative index of channel and riparian habitat condition calculated from
quantitative habitat measurements and visual cover estimates or tallies. The index evaluates
the judged quality of the site with respect to eight dimensions of habitat structure, each
represented as the mean of 2-11 separate scored metrics:
(a) Riparian vegetation (complexity, cover)
(b) Riparian disturbances (sum of proximity-weighted tallies of 11 types of disturbances)
(c) Channel bed surface substrate (% silt, % sand, % fine gravel, % embeddedness, %
bedrock + hardpan, % macrophyte cover, % filamentous algae cover)
(d) Channel alteration (presence of pipes, revetment, or bed substrates composed of
concrete or asphalt; relative bed stability; deviation from residual pool volume predicted
from stream size and slope)
(e) Habitat volume (mean wetted width, mean channel cross-section area, mean residual
depth, %dry channel)
(f) Channel spatial complexity (CV thalweg depth, CV wetted width, fish-macroinvertebrate
cover variety)
(g) Cover magnitude (separate and sum of six cover types)
(h) Velocity and bed shear stress (mean slope, shear stress index)
Notes: Metric a = mean of subcomponents; metric b = mean of subcomponents; etc. for eight
metrics.
For example, the first dimension, riparian vegetation, is calculated as the mean of scored
metrics for riparian-structural complexity and cover. Before calculating the mean, the two
subcomponent metrics were scored with respect to their influence on biotic assemblage
integrity from 0 (‘‘lethal’’) to 1 (‘‘optimal’’), based on the collaborative professional judgement
of four aquatic ecologists and four aquatic resource managers.
74
4.3
The total QTPH score is computed as the geometric mean of the eight scaled habitat
dimensions, giving zero values to the total if only one of the dimensions is scored as lethal.
Like the metric scores, the QTPH index score for a site ranges from 0 (lethal) to 1.0
(optimal).
QTPH = (a b c d e f g h) (1/8) = geometric mean of subcomponents
4.3.5 Illustration and Documentation of the Results
NÖMORPH
The results of the NÖMORPH mapping were illustrated for whole river courses using maps
(with a scale of 1:50000). The condition of the 5 single summarizing parameters was
presented by means of tables and verbal description.
Data were integrated into the Wasserdatenverbund of Lower Austria - an information system
for the recording, administration, and evaluation of data concerning water (cf. freiland
Umweltconsulting 2001).
The Environmental Monitoring and Assessment Program Western Pilot Study (EMAP-W)
presented the results of the Physical Habitat Characterization with the help of maps, graphs,
tables, and verbal description.
For the presentation three different levels of geographic resolution were used:
-
West-wide (12 states)
Three major climatic/topographic regions – Mountains, Plains and Xeric
Ten ecological regions – aggregated from Omernik Level III (Omernik 1987)
ecoregions (cf. Stoddard et al. 2005)
75
5
Study Area
5
Study Area
During the preparation phase of the thesis it became apparent to focus on one river system
to get a consistent image after the evaluation and analysis of the data and the methods. As
the field work could not be done within a few days due to weather conditions and time
management, the watershed of the river Traisen was the first choice due to its proximity to
Vienna and its reachability.
After studying the ÖK 50 maps and an inspection in the field, sites of four different
headwaters and tributaries were chosen to be observed. The main decision criteria were on
the one hand to get an overview of the variety of the Traisen river system concerning
geology, altitude, morphological river types, valley shapes, stream orders and human
alterations. On the other hand, the survey stretches had to be not too remote and moreover
wadeable as the field work and the transportation of the equipment was done by only one
person. Of special interest was the applicability of the methods for the assessment of
residual water stretches.
The selected streams are all situated upstream of St.Pölten because there are hardly any
major Traisen tributaries along the lower course. The four sites were subdivided into four
reaches, each with a determined length of 150m to enable the comparison of the applied
inventory methods.
5.1
Traisen
Basic Data
Upper Course:
Geology: Limestone-Pre-Alps
Valley Type: V-shaped valley, V-shaped valley with narrow bottom, valley with distinctive
bottom
Middle Course:
Geology: Flysch Zone
Valley Type: Valley with distinctive bottom
Lower Course:
Geology: Molasse Zone
Valley Type: Valley with distinctive bottom, valley plain (NÖMORPH 2001)
Altitude: 1000m - 180m (NÖMORPH 2001)
Altitudinal Belt: montane, submontane, collin, planar (Ellenberg 1963)
Morphological River Type: diverse morphological river types are existent in the catchment
area of the Traisen (see Figure 4)
Stream Order at Mouth (Strahler): 6 (NÖMORPH 2001)
Catchment Size: 900km² (Muhar et al. 1998)
Hydrological Regime: Nival, Nivo-pluvial , Pluvio-nival (Preis and Schager 2000)
Mean Annual Discharge: 13.1 m³/s, 1981-1996, gauging station Windpassing (BMLFUW
1999)
Mean Annual Water Temperature: 8.9° C, 1981-1990, gauging station Windpassing
(BMLFUW 1994)
Biocoenotic Region: Epi-, Meta-, Hyporhithral, Epipotamal (BMLFUW 2009)
Mouth: Danube
The main source of the Traisen is the Traisenbach which flows into the Türnitzer-Traisen in
Türnitz. The Traisen itself has two main headstreams: the Türnitzer-Traisen and the
Unrechttraisen that join in Freiland. Downstream of the confluence the river flows northwards
to leave the Northern Limestone Alps near the market town Traisen.
76
5
Study Area
The middle course is characterized by the Flysch Zone. Coming from the East, the Gölsen,
the Traisen’s main tributary, flows into the river.
Downstream of Wilhelmsburg the Traisen flows in a wide valley through the Molasse Zone,
passing St.Pölten, the capital of Lower Austria , until its confluence with the Danube.
Figure 19: Map of Austria. Location of the Traisen catchment area in Lower Austria.
(BEV 2011, modified by Jochen Steindl)
Figure 20: Catchment of the Traisen and its tributaries upstream of St.Pölten.
The map illustrates the location of the 4 surveyed sites: Site 1 at the Retzbach, Site 2 at the
Steinpartztalbach, Site 3 at the Ramsaubach, and Site 4 at the Kreisbach (Eberstaller et al.
2007, modified by Jochen Steindl).
77
5
Study Area
5.2
Retzbach (Site 1)
Basic Data
ID surveyed reaches: Niederbach: 1/1, Retzbach: 1/2, 1/3, 1/4 (see Figure 21 and Figure
22)
Geology: Limestone-Pre-Alps (BMLFUW 2009)
Altitude: circa 555m
Altitudinal Belt: submontane (Ellenberg 1963)
Valley Shape: V-shaped valley
Morphological River Type: constrained
Stream Order (Strahler): Retzbach: 2, Niederbach: p (intermittent) (Umweltbundesamt
1994)
Catchment Size: >10km² (Eberstaller et al. 2007)
Hydrological Regime: Pluvio-nival (Preis and Schager 2000)
Biocoenotic Region: Epirhithral (BMLFUW 2009)
Mouth: Traisenbach
The Retzbach is dominated by a V-shaped valley until the valley widens in Weidenaurotte
and the stream joins the Traisenbach, the major Traisen headwater. Along its alternately
straight and sinuous course with local broadenings and side channels (Eberstaller et al.
2007) there are 6 small hydro power plants (cf. Wagner 2011, telephone interview).
In 2005, during a major flood event, the Retzbach destroyed the road upstream of
Weidenrotte when it tried to recapture the original river bed. As the valley of the Retzbach is
intensively used by hikers and for logging, the road has been rebuilt (cf. Wagner 2011,
telephone interview). Under natural conditions the river would partially influence the whole
valley bottom.
The survey reach 1/1 Niederbach is situated upstream of the impoundment of a small
hydropower station where the small river flows into the Retzbach. The hydro power station
belongs to the land owner who uses the energy for his villa in Niederbach (cf. Wagner 2011,
telephone interview). Three reaches were surveyed at the Retzbach, one at the Niederbach.
Figure 21: Location of Site 1, Retzbach.
78
5
Study Area
Figure 22: Location of the sample reaches of Site 1.
5.3
Steinpartztalbach (Site 2)
Basic Data
ID surveyed reaches: 2/1, 2/2, 2/3, 2/4 (see Figure 23 and Figure 24)
Altitude: circa 530 m
Altitudinal belt: submontane (Ellenberg 1963)
Valley shape: V-shaped valley
Morphological river type: pendulous
Stream order (Strahler): 1 (Umweltbundesamt 1994)
Catchment size: <10km² (Eberstaller et al. 2007)
Hydrological regime: Moderate nival (Preis and Schager 2000)
Biocoenotic region: Epirhithral (BMLFUW 2009)
Mouth: Unrechttraisen
The Steinpartztalbach is a left tributary of the Unrechttraisen in Hohenberg. It is incised in a
V-shaped valley with a steep slope and insular broadenings until it enters the settlement area
of Hohenberg where the valley floor widens and the river is heavily altered because of
regulations and impoundments. Through the valley runs a gravel road up to the mountains
that is used for logging and by excursionists.
79
5
Study Area
Although the river bed along the sample reaches is sporadically influenced by human
alterations such as riprap and small bridges, it mostly has a near-natural character. What is
noticeable are accumulations of grit supposably caused by the input of fine gravel and fines
from the road.
Figure 23: Location of Site 2, Steinpartztalbach
Figure 24: Location of the sample reaches of Site 2.
80
5
Study Area
5.4
Ramsaubach (Site 3)
Basic Data
ID surveyed reaches: 3/1, 3/2, 3/3, 3/4 (see Figure 25 and Figure 26)
Altitude: circa 450m
Altitudinal belt: collin (Ellenberg 1963)
Valley shape: Valley with distinctive bottom
Morphological river type: pendulous
Stream order (Strahler): 4 (Umweltbundesamt 1994)
Catchment size: >10km² (Eberstaller et al. 2007)
Hydrological regime: Pluvio-nival (Preis and Schager 2000)
Mouth: Gölsen
The Gölsen river is the major tributary of the Traisen, it is joined by the Ramsaubach in
Hainfeld. The Ramsaubach flows through a V-shaped valley with a sectional broad valley
floor (cf. Eberstaller et al. 2007) The adjacent area of the river is characterized by agriculture,
settlements, industry and forestry.
Downstream of the surveyed site there are 4 small hydro power stations. One of them
influences the surveyed site because water is diverted at sample reach 3/3 into a canal and
piped through a hill to the hydro power station so that the residual water stretch is dry during
low flow periods (Municipal Office of Hainfeld 2011, telephone interview).
Reach 3/4 is also a residual water stretch, the water extraction is not as devastating as
downstream.
Figure 25: Location of Site 3, Ramsaubach (BEV 2011, modified by Jochen Steindl).
81
5
Study Area
Figure 26: Location of the sample reaches of Site 3 (BEV 2011, modified by Jochen
Steindl).
( A large amount of water is abstracted at reach 3/3 and only partly flows back into the river
at reach 3/1, most of the water runs through the hill to a small hydropower station)
5.5
Kreisbach (Site 4)
Basic Data
ID surveyed reaches: Münichwaldgraben: 4/1, Kreisbach: 4/2, 4/3, 4/4 (see Figure 27 and
Figure 28)
Geology: Flysch- and Sandstone-Pre-Alps (BMLFUW 2009)
Altitude: circa 350m (ÖK)
Phytosociological units / altitudinal belt: collin (Ellenberg 1963)
Valley shape: V-shaped valley incised in a synclinal valley (Preis and Schager 2000)
Morphological river type: constrained
Stream order (Strahler): Kreisbach: 3, Münichwaldgraben: 2 (Umweltbundesamt 1994)
Catchment size: >10km² (Eberstaller et al. 2007)
Hydrological regime: Pluvio-nival (Preis and Schager 2000)
Mouth: Traisen
The Kreisbach, whose mouth lies in the urban area of Wilhelmsburg, is a right tributary at the
middle course of the Traisen. The river is incised in a synclinal valley with large-scale
broadenings that is heavily influenced by agriculture.
Three reaches were surveyed along the Kreisbach and one at the Münichwaldgraben, a left
tributary of the Kreisbach.
82
5
Study Area
Figure 27: Location of Site 4, Kreisbach
(BEV 2011, modified by Jochen Steindl).
Figure 28: Location of the sample reaches of Site 4
83
6.1
6
Reference Conditions and Results Retzbach (Site 1)
Reference Conditions and Results
This section of the thesis describes the reference conditions for the 4 survey sites on the
basis of the river type regions and the morphological river types. In addition, the results of the
data evaluation are presented.
Data have been calculated and processed with the help of the Microsoft Excel program for
each of the 16 reaches of the 4 survey sites. The results are illustrated using tables as well
as figures, generated with a GIS application, showing whole-reach averages, reach level
percentages, and condition classes.
For each sampled reach a recapitulatory presentation of the conclusions and the results
based on the 5 summarizing parameters of the NÖMORPH method is attached to
demonstrate correspondences between the results of the applied methods (see also
APPENDIX B. Assessed Parameters of the NÖMORPH method and the Physical Habitat
Characterization).
Furthermore, photo documentations are used to complete the characterization of the results.
For information concerning data evaluation and calculations see 4.2.1 NÖMORPH –
Ecomorphological Mapping of Selected Running Waters in Lower Austria and 4.2.2 Physical
Habitat Characterization.
6.1 Retzbach (Site 1)
6.1.1 Reference Conditions
The reference condition respectively the general principle of the Retzbach were defined with
the help of the River Type Region and the Morphological River Type:
River Type Region
The Retzbach and the Niederbach are water bodies of the Limestone-Pre-Alps (see Figure
2) for which the summarizing parameters are described as follows (translated from freiland
Umweltconsulting 2001):
“Riverbed
Spring areas: Springs emerge from screes. Several river stretches partially fall dry and the
river flows underground through the hyporheic interstitial.
The permeable substrate is mostly coarse and edged (Meso- and Makrolithal - see Appendix
B, hardly fine material).
Heavy movement and changing processes; few sediment banks. Small scale formations of
islands are possible at bends of the ground.
Banks / Riparian Zone
The bank vegetation is weakly developed because of erosion and changing processes. In
middle courses in parts limestone bedrock at outer banks.
Along middle and lower courses sinuous river stretches occur. The dominant substrate class
is Mikrolithal (see Appendix B), partially limestone bedrock at the bottom. There are no
backwaters.
84
6.1
Vegetation
Upper course: Beech woods (Fagus sylvatica) on the hillsides. The herbaceous bank
vegetation is limited to Butterbur (Petasites sp.) on gravel banks.
Middle course: Black Alder (Alnus glutinosa), Ash (Fraxinus excelsior), Willows (Salix sp.);
partially deciduous wood adjacent without transition.”
At the sample reaches the morphological type of the Retzbach and the Niederbach is
constrained which means that the slope is steep and the lateral dynamic development is
limited because of bedrock conditions (constrained channel). The constrained morphological
river type mostly appears in V-shaped valleys, gorges, and V-shaped valleys with a narrow
bottom (translated from freiland Umweltconsulting 2001):
“Channel Geometry and Flow Characteristics
- only narrow gravel and sediment banks
- little bottom width
- turbulent flow conditions
- no backwaters
Riverbed
Only few morphological differentiations because of the constraining features:
- limited width- and depth- variance
- substrate mainly cobbles and boulders, gravel on inner banks
- numerous natural riverbed drops, frequent slope changes (pool, riffle)
The connectivity between water and land is far less distinctive compared to braided
stretches.
- small-scale accumulations that can build fish cover during floods
- low width variability, smaller than 1:2
- wetted margin dominated by cobbles and boulders due to bedrock material, fish cover
in interstices and behind large boulders
Heavily eroded banks with many undercuts and narrow azonal vegetation often change over
to wooded hillsides. Inner banks with small-scale gravel banks and boulders overgrown with
moss. Behind it steep acclivities as a result of erosion.
Vegetation
- moss (water and land)
- pioneer plants on coarse substrate : Butterbur (Petasites sp.), Rush Skeletonweed
(Chondrilla sp.)
- Reedgras (Calamagrostis pseudophragmites) and Reed Canary Grass (Phalaris
arundinacea)
- tall herbaceous vegetation (often very narrow)
- floodplains dominated by Grey Alder (Alnus incana)
- floodplains dominated by Ash (Fraxinus excelsior)
- humid hillside-forests with the character of ravine forests, dominated by Sycamore
Maple (Acer pseudoplatanus) and Ash (Fraxinus excelsior)”
85
6.1
6.1.2 Results: NÖMORPH
The outcomes of the hydromorphological assessment with the NÖMORPH method are
presented using tables. The evaluated condition classes, calculated separately for the left
and the right banks, were transformed to the classification of the Water Framework Directive
and are mapped on an orthophoto (see Figure 29).
Table 25 illustrates the results of the calculated summarizing parameters for each of the 4
sample reaches of Site 1. In the last line are the corresponding condition classes. (L = left
bank, R = right bank).
Table 25: Results of the evaluation of the 5 summarizing parameters - Site 1.
1/1 L
1/1 R
1/2 L
1/2 R
1/3 L
1/3 R
1/4 L
1/4 R
1-2
2-3
2-3
1
1-2
1
2-3
1
2
2
1-2
1-2
1-2
1-2
1-2
1-2
Connectivity water land
1-2
2-3
2-3
1
2
1
2-3
1
Banks/Riparian Zone
1
2-3
2-3
1-2
2-3
1-2
2-3
1-2
Vegetation
Surroundings
1-2
2-3
2
1-2
1-2
2
2-3
1-2
Overall Condition
Class
1-2
2-3
2
1
2
1-2
2-3
1
Channel Geometry
and Flowability
Riverbed
Summarizing parameters are presented in detail with the help of the results of the Physical
Habitat Characterization - see Summarizing Presentation of Conclusions and Results
attached to the presentation of Physical Habitat Characterization outcomes for the individual
sample reaches.
Table 26 shows the evaluated condition classes for the NÖMORPH method and their
transformation to the classification of the Water Framework Directive (see also Table 24).
Table 26: NÖMORPH - Results of the total evaluation for Site 1.
Reach ID
1/1
1/1
1/2
1/2
1/3
1/3
1/4
1/4
Bank
Left
Right
Left
Right
Left
Right
Left
Right
Status NÖMORPH
1-2
2-3
2
1
2
1-2
2-3
1
Status WFD
1
2
2
1
2
1
2
1
86
6.1
Figure 29: NÖMORPH evaluation of Site 1, Retzbach.
The illustration shows the results of the total evaluation of the NÖMORPH survey for both
banks using the transformed figures of the Water Framework Directive. The blue colour
represents condition class 1, the green colour condition class 2. (Orthophoto by BEV).
The right bank at reach 1/1 (Niederbach) and the left banks of the reaches 1/2-1/4 are in
worse condition then the other banks of the reaches. The main reason for this is the heavy
influence of the gravel roads that run directly along the rivers because of the narrow valley
form. The transformed figures of the WFD represent the same conclusion, even though the
additional information of the intermediate classes is lost due to the transformation.
87
6.1
6.1.3 Results: Physical Habitat Characterization
The following tables and graphs illustrate the results for all four surveyed reaches of Site 1.
The outcomes for Habitat Characteristics, Large Woody Debris, “Legacy” Trees, and Alien
Plant Species are presented together. The results for Habitat Classes, Substrate Classes,
Fish Cover, Vegetation Cover, and Human Influences are displayed individually for the single
sample reaches.
Table 27: Results of the physical habitat measurements respectively estimations for
Site 1.
Reach 1/1
Reach 1/2
Reach 1/3
Reach 1/4
Flow Velocity Estimation (ms−1)
0.33
0.49
0.62
0.56
Discharge Estimation (m³s−1)
0.11
0.33
0.40
0.34
1.89
4.32
3.82
4.04
2.80
7.10
5.10
5
0.59
0.56
0.50
0.55
1.2
1.3
0.9
1.2
19
29
27
30
84
27
54
42
44
25
31
39
0.06
0
0.14
0
0
0
0
0
Mean Bar Width (m)
0
0.08
0
0
5.2
5.4
5.6
4.9
57
38
41
50
Slope Total (%)
27
15
16
17
0.45
0.25
0.25
0.25
Sinuosity
1.2
1.1
1
1
Mean Canopy Cover left (%)
85
56
53
52
Mean Canopy Cover right (%)
74
60
70
75
LWD all/part in bankfull channel (m³)
0
2.21
0.80
1.03
LWD above bankfull channel (m³)
0
0
0.12
0.18
Habitat Characteristics
As can be seen from Table 27, the calculations of the habitat characteristics measurements
indicate some noticeable results:
•
•
•
•
•
High flow velocity
Only a few minor undercuts
Hardly any sediment bars
Lower canopy cover on sides influenced by gravel roads
LWD nearly absent
88
6.1
•
Large Woody Debris
At the whole Site LWD is rare. Especially above the bankfull channel hardly any pieces could
be found and even within the bankfull channel only smaller pieces were counted as larger
pieces were missing. The volume of LWD is only higher at reach 1/2, at reach 1/1 LWD is
totally absent (see Figure 30 and Figure 31).
2.50
xdll
xdml
2.00
xdsl
Volume m³
ldll
1.33
1.50
ldml
ldsl
mdll
1.00
mdml
0.33
0.18
0.33
sdll
0.50
0.70
mdsl
0.70
0.46
sdml
sdsl
0.00
Reach 1/1
Reach 1/2
Reach 1/3
Reach 1/4
Figure 30: Large Woody Debris all/part in bankfull channel.
(sdsl: small diameter-small length; sdml: small diameter-medium length; sdll: small diameterlarge length; mdsl: medium diameter-small length; mdml: medium diameter-medium length;
xdml: extra large diameter-medium length; xdll: extra large diameter-large length)
2.50
xdll
xdml
2.00
xdsl
Volume m³
ldll
ldml
1.50
ldsl
mdll
1.00
mdml
mdsl
sdll
0.50
sdml
sdsl
0.00
Reach 1/1
Reach 1/2
0.12
0.18
Reach 1/3
Reach 1/4
Figure 31: Large Woody Debris above bankfull channel.
89
6.1
•
“Legacy” Trees and Alien Plant Species
Typical trees for this river type region could be found at all reaches. The domination of
Norway Spruce (Picea abies) at all reaches except reach 1/2 is obvious. Most reported
“Legacy” trees were trees within the height class 15-30m. Alien plant species were absent
(see Table 28).
Table 28: Largest visible potential “Legacy” Tree and Alien Plant Species.
Largest potential Legacy Tree visible
(quantity)
Height (quantity)
Mean Distance from wetted
margin (m)
Type (quantity)
Taxonomic Category
(quantity)
Reach 1/1 Reach 1/2 Reach 1/3 Reach 1/4
0 - 0.1m
0.1 - 0.3m
0.3 - 0.75m
0.75 - 2m
>2m
<5m
5 - 15m
15 - 30m
>30m
Coniferous
Deciduous
Picea abies
Acer
pseudoplatanus
Fagus sylvatica
2
9
10
1
9
2
2
8
1
11
1
10
1
10
3
8
3.9
7.3
8.5
3.8
8
3
8
5
6
5
9
2
9
11
1
1
2
5
11
2
90
6.1
6.1.3.1 Reach 1/1
The right tributary of the Retzbach flows
through a V-shaped valley. Its course is
heavily constrained by a gravel road and the
hillside. A fence hinders hikers to enter the
nearby private property.
Figure 32: Niederbach, reach 1/1.
Mouth of the Niederbach into the
the impoundment of a small
plant. The slow flowing water is
deep. The Niederbach has
sediment bank, mostly cobble
gravel.
Retzbach at
hydropower
about 2-3m
created a
and coarse
Figure 33: Impoundment of the Retzbach river.
Reach 1/1
3% 1%
7%
4%
4%
Cascade
Glide
Lateral Scour Pool
Even though the reach consists
of different types of habitats, it is
dominated by riffle sections,
followed by pools in a variety of
shapes.
Plunge Pool
Trench Pool
Riffle
81%
Reach 1/1
3%
3%
5%
12%
Bedrock (rough)
2%
9%
Boulders (large)
Boulders (small)
27%
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
21%
18%
Fines
Concrete
The major substrate classes are
gravel and cobble. Sand and
fines play an insignificant role.
Even
if
the
substrate
composition may appear natural
at the first sight, the impact of
the adjacent road must not be
neglected. A culvert under the
gravel road is made out of
concrete.
Figure 34: Reach 1/1 - Habitat classes and substrate classes.
91
6.1
Cover Percentage
20
15
16
10
12
8
4
2
4
0
0
0
0
0
St
ru
ct
ur
es
rs
Ar
tif
ic
ia
l
Bo
ul
de
an
ks
<1
m
Un
de
rc
ut
B
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
in
g
Tr
ee
s/
R
e
Li
v
y
Br
us
h/
W
oo
d
W
oo
dy
D
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
Fi
la
m
M
en
to
us
Al
ga
e
0
Figure 35: Reach 1/1 - Fish cover.
Fish find cover mainly under boulders and overhanging vegetation. In general, fish cover is
rare what could be observed during the field work when fish tried to find a place to hide.
55
52
50
40
43
33
25
15
Herbs/Grasses/Forbs
Shrubs/Saplings
Shrubs/Saplings
Small Trees <0.3m
Canopy >5m high
Herbs/Grasses/Forbs
5
10
0
Big Trees >0.3m
Percentage
30
20
Understory 0.5 - 5m high
Barren/Bare Dirt/Duff
70
60
Ground Cover <0.5m high
Canopy >5m high
9%
9%
27%
Deciduous
Mixed
Mixed
None
91%
None
64%
Figure 36: Reach 1/1 - Riparian vegetation cover - left bank.
92
6.1
The left bank of the reach is densely covered by trees of a mixed hillside forest. Trees higher
than 5m with a DBH >0.3m are as frequent as trees with a DBH <0.3m. The understory is not
significantly pronounced and mixed at 64% of the transects, at 27% of the transects it is
deciduous. Ground cover is dominated by herbs, grasses, and forbs, followed by barren,
bare dirt, and duff. Small shrubs and saplings play a minor role.
70
60
50
57
40
30
16
16
16
6
5
Canopy >5m high
Canopy >5m high
18%
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
20
10
29
9%
18%
Deciduous
Deciduous
Mixed
Mixed
None
None
18%
64%
73%
Figure 37: Reach 1/1 - Riparian vegetation cover - right bank.
Due to the gravel road riparian vegetation cover is not in good condition on the right bank.
Canopy cover, that is at some transects nearly absent, is dominated by mixed vegetation.
The understory is even less developed and characterized mainly by deciduous small trees
and shrubs. 57% of the ground cover is not vegetated and consists mainly of gravel.
93
6.1
Mean Weighting
1.5
1.2
0.9
0.6
0.5
0.3
0.3
Di
k
0.3
0
0
0
0
0
le
ar
ed
Pa
ve
m
en
t/C
Bu
ild
in
gs
e/
Re
ve
tm
en
t /R
ip
ra
p
0
0
0.1
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fil
/T
ra
sh
Pa
rk
/L
aw
n
Pa
R
st
o
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
ity
0.1
Figure 38: Reach 1/1 - Human disturbances and influences - left bank.
The left bank of the reach is not heavily influenced by human impacts. The upper section is
artificially altered because of a culvert under the gravel road.
1.5
Mean Weighting
1.4
1.2
1.1
0.9
0.6
0.3
0.3
0.2
0
0.3
0
0
0
0
0
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fil
/T
ra
sh
Pa
rk
/L
aw
n
Pa
R
st
o
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
ity
le
ar
ed
en
t/C
Bu
ild
in
gs
Pa
ve
m
Di
ke
/R
ev
et
m
en
t /R
ip
ra
p
0
Figure 39: Reach 1/1 - Human disturbances and influences - right bank.
The gravel road has led to heavy disturbances of the right bank and the adjacent area. Due
to logging transportation and regular maintenance measures a development of a near-natural
condition is not possible.
94
6.1
6.1.3.1.2
Summarizing Presentation of Conclusions and Results
This section demonstrates the correlations between the results of the NÖMORPH method
and the Physical Habitat Characterization method with the help of the detailed
characterizations of the 5 summarizing parameters (see Table 25 and section 7 Discussion).
Left bank
The left side of reach 1/1 is not heavily influenced by human impacts. This is illustrated by
the NÖMORPH results as well as by the measurements and estimations of the Physical
Habitat Characterization.
The riverbed evaluation resulted in condition class 2 due to occasional alterations along the
riverbed and of the substrate composition caused by concrete (substructure of a bridge) that
also influences the hyporheic interstitial (see also Figure 34).
The connectivity of water and the riparian area is sporadically disturbed by riprap and
concrete which leads to a slightly modified condition (1-2). Even though large woody debris is
absent (see Figure 30), Figure 35 shows that fish cover is present, mainly composed of
boulders, overhanging vegetation, and undercut banks.
Vegetation cover of the riparian zone and the surroundings is near-natural. This conclusion is
also affirmed by Figure 36 and Figure 38: Canopy, understory, and ground cover are
consisting of mixed and native plants. Logging operations and agricultural areas are absent.
Right Bank
The right bank is significantly influenced by a gravel road as illustrated by Figure 39. The
results are slightly to heavily modified conditions of the summarazing parameters (see Table
25).
Concerning channel geometry and flowability dynamic processes are limited and the river
course is restricted because of riprap (see Figure 39).
The riverbed evaluation resulted in condition class 2 due to occasional alterations along the
riverbed and of the substrate composition caused by concrete (substructure of a bridge) that
also influences the hyporheic interstitial (see also Figure 34).
The connectivity of water and land is characterized by the significant limitation of lateral
dynamic processes and the sporadical lack of natural structures.
The typical characteristics of the bank and the riparian zone are heavily altered because of
riprap and the gravel road. The vegetation cover is disturbed - canopy, understory, and
vegetated ground are nearly absent (see Figure 37).
The vegetation of the surroundings is also modified as there is no vegetation buffer and no
understory.
95
6.1
6.1.3.2 Reach 1/2
Mouth of the Retzbach into the impoundment.
There is a large-scale sedimentation of bed
load, mostly cobble and coarse gravel. The
road was rebuilt after a flood in 2005.
Figure 40: Retzbach, reach 1/2.
The whole left bank of the reach is influenced
by a gravel road used by hikers, local
residents, and for logging transportation. The
input of fines and sand is existent but not
significant as the transportation rate is high
due to flow velocity especially during flood
events.
Reach 1/2
12%
5%
4%
1%
Lateral Scour Pool
Plunge Pool
Trench Pool
Rapid
Riffle
78%
Reach 1/2
6%
14%
2% 1% 1%
4%
13%
Bedrock (smooth)
Bedrock (rough)
Boulders (large)
Boulders (small)
Cobbles
Gravel (coarse)
Typical for the whole site is the
pool-riffle-sequence: 78% of
the reach are characterized by
riffle sections, 21% by pools.
Some of the larger pools are
important habitats for adult
fish.
The substrate classes are
dominated by cobbles and
coarse gravel. 8% are fines
and sand, 14% fine gravel.
17% of the observed substrate
classes are large and small
boulders.
Gravel (fine)
25%
34%
Sand
Fines
96
6.1
Cover Percentage
24
21
20
16
12
8
5
4
0
0
5
2
1
0
2
Ar
tif
ic
ia
l
St
ru
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
e
Li
v
y
Br
us
h/
W
oo
d
W
oo
dy
D
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
Fi
la
m
M
en
to
us
Al
ga
e
0
Boulders are the only major cover for fish with 21%, followed by brush/small woody debris
and undercut banks with 5%.
70
60
50
40
26
25
20
19
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
Canopy >5m high
Herbs/Grasses/Forbs
7
6
Big Trees >0.3m
Percentage
30
20
10
0
60
Canopy >5m high
9%
27%
27%
Deciduous
Deciduous
Mixed
Mixed
None
64%
73%
Figure 44: Reach 1/2 left bank - Riparian vegetation cover.
97
6.1
Canopy and understory are artificially altered because of the gravel road. At most transects
the vegetation is mixed, at 27% of the transects the vegetation is deciduous at both layers canopy and understory. The ground cover is heavily altered: 60% are not vegetated.
70
46
43
35
28
5
5
Herbs/Grasses/Forbs
Shrubs/Saplings
20
Canopy >5m high
Canopy >5m high
9%
91%
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
60
50
40
30
20
10
18%
Coniferous
Deciduous
Mixed
Mixed
82%
Figure 45: Reach 1/2 right bank - Riparian vegetation cover.
The canopy cover of the right bank dominated by mixed vegetation as well as the vegetation
of the understory. Cover is not significant at both layers. The high percentage of barren at the
ground layer is the result of a large sediment accumulation at the mouth of the Retzbach into
the impoundment at the small hydropower station. 48% of the ground is overgrown, mostly
with herbs, grasses, and forbs.
98
6.1
1.5
Mean Weighting
1.5
1.5
1.2
0.9
0.6
0.3
0.1
0
0
0
0
0
Bu
i ld
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
f ill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
ity
0.3
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
0.3
0
Figure 46: Reach 1/2 left bank - Human disturbances and influences.
The left bank of the reach is heavily influenced and altered because of the gravel road. The
whole length is constrained by overgrown riprap that has sporadically been renewed.
Mean Weighting
1.5
1.2
0.9
0.6
0.3
0
0
0
0.3
0
0
0
0
0
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
0
Bu
ild
in
en
gs
t /C
le
ar
ed
Lo
R
t
oa
d/
Ra
Pi
ilr
pe
oa
s
d
( In
le
t/O
ut
le
t)
La
nd
fil
l/T
ra
sh
Pa
rk
/L
aw
n
P
Ro
as
tu
w
re
Cr
/R
op
an
s
ge
/H
ay
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
ity
0.1
Figure 47: Reach 1/2 right bank - Human disturbances and influences.
There are hardly any human disturbances along the right bank.
99
6.1
6.1.3.2.1
Left bank
The left bank of reach 1/2 is disturbed because of riprap and a gravel road (see Figure 46).
Along the riverbed there are occasional accumulations of small substrate caused by the input
from the gravel road (see Figure 42).
The result of the classification for channel geometry, flowability, and the connectivity of water
and land is condition class 2-3 because lateral dynamic processes are limited, the course of
the river is restricted, and natural structures are sporadically absent. Fish cover is frequent
due to boulders including riprap.
The typical characteristics of the banks are heavily altered which is illustrated mainly by the
modified vegetation cover: canopy and understory are nearly absent, the ground is
dominated by barren (see Figure 44).
Even though the vegetation of the surroundings is dense, due to the road plants as buffer
zone are nearly absent and the adjacent vegetation cover disturbed.
Right Bank
The conditions of the right bank are only slightly modified.
from the gravel road (see Figure 42).
The connectivity of water and land is natural, large woody debris is more frequent than along
other reaches (see Figure 30).
The vegetation cover of the riparian zone and the surroundings is sporadically disturbed.
100
6.1
6.1.3.3 Reach 1/3
The course of the Retzbach is straight as it
would be under undisturbed conditions. Here
the right bank is constrained by a hillside, the
left bank by an artificial accumulation of old
riprap and boulders that have been vegetated
over the years and led to a near-natural
status.
Along this reach the road does not run
directly on the bank of the Retzbach.
Boulders have been placed to hinder the river
from destroying the road as during a major
flood event in 2005. Sporadically, there are
trees and the boulders are overgrown with
grasses and young shrubs.
Reach 1/3
9%
5%
4%
2%
Glide
Lateral Scour Pool
Trench Pool
Rapid
Riffle
The habitat class composition is
dominated
by riffle sections.
Whereas pools are rare, there is
an important occurrence of
glides.
80%
Reach 1/3
6%
4%
7%
14%
21%
Bedrock (rough)
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
Coarse substrate sizes are very
frequent along this reach:
boulders 28%, cobbles 29%, and
coarse gravel 19%. There is also
a higher percentage of fines and
sand: 10%. Smooth or rough
bedrock is absent.
Sand
19%
Fines
29%
101
6.1
Cover Percentage
30
26
24
18
15
10
12
6
0
0
5
3
2
0
Ar
tif
ic
ia
l
St
ru
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
oo
ts
ov
er
ha
ng
in
g
Tr
ee
s/
R
e
Ve
ge
t
at
io
n
Br
us
h/
W
oo
d
Li
v
y
D
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
W
oo
dy
Fi
la
m
M
en
to
us
Al
ga
e
0
Compared to other reaches fish cover is quite frequent: boulders are dominating again, but
there is a major appearance of undercut banks and overhanging vegetation.
70
60
51
44
50
40
30
20
10
0
36
34
16
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Shrubs/Saplings
Canopy >5m high
Herbs/Grasses/Forbs
10
Small Trees <0.3m
Big Trees >0.3m
Percentage
19
27%
37%
Conif erous
Deciduous
Mixed
Mixed
None
27%
9%
100%
102
6.1
On the left bank and the adjacent area canopy cover is sparse and often nearly absent. At
most transects the vegetation was coniferous or mixed. The mixed vegetation of the
understory is characterized by shrubs, saplings, and grasses. Even if the ground is mostly
covered by plants, barren plays a major role.
71
41
35
22
22
20
Canopy >5m high
Canopy >5m high
9%
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
9
Big Trees >0.3m
Percentage
80
70
60
50
40
30
20
10
0
9%
18%
Coniferous
Deciduous
Mixed
Mixed
None
73%
91%
The canopy cover is not significant along the right bank, the understory is dominated by
shrubs and saplings. Herbs, grasses, and forbs cover a major part of the ground with an
average of 71% at the transects.
103
6.1
1.5
Mean Weighting
1.2
1.1
0.9
0.6
0.7
0.3
0.4
0.3
0
0.1
0
0
0
0
Bu
ild
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/ O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
R
st
ow
ur
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
it y
0
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
As the road does not run along the bank of this reach its influence is not as heavy as at the
other reaches but still obvious. Other present human impacts are: cleared lots, riprap, and
pipes.
Mean Weighting
1.5
1.2
0.9
0.6
0.3
0
0
0
0.1
0
0
0
0
0
Bu
il d
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
P
as
Ro
tu
w
re
Cr
/R
op
an
s
ge
/H
a
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
t iv
it y
0.3
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t /R
ip
ra
p
0
0
The right bank is not significantly disturbed by human influences and alterations.
104
6.1
6.1.3.3.1
Left bank
The left bank of reach 1/3 is in better condition than the left bank of reach 1/2 as the road
does not run exactly along the river. This is also represented by Figure 54: the influence of
the road is still present but weaker. Consequently, the status of most summarizing
parameters is higher valued.
Channel geometry and flowability: Dynamic processes are limited and there are occasional
human influences but the course of the river is still near-natural.
from the gravel road. Figure 50 illustrates that there is a higher percentage of fines.
The connectivity of water and land is slightly modified due to sporadical human disturbances
which lead to a reduction of lateral dynamic processes and a sporadical lack of natural
structures. Undercut banks are quite frequent compared to other sample reaches (see also
Figure 51).
The typical characteristics of the riparian zone are altered and vegetation cover is
significantly disturbed. Figure 52 shows that canopy cover was absent at some transects.
There is only a narrow vegetation buffer zone, vegetation cover of the surroundings is slightly
modified.
Right Bank
Channel geometry and flowability of the right side are in natural condition.
Substrate composition is slightly influenced by occasional accumulations of small substrate
caused by the input from the gravel road. Figure 50 illustrates that there is a higher
percentage of fines.
The connectivity of water and land is not modified by human alterations (see Figure 55). Fish
cover is diverse and frequent (see Figure 51).
The riparian zone is affected by minor alterations of the typical characteristics vegetation
cover is insignificantly disturbed (see Figure 53 and Figure 55).
The vegetation cover of the surroundings is significantly disturbed because of cleared lots
and a high percentage of coniferous trees (Picea abies).
105
6.1
6.1.3.4 Reach 1/4
The river is mostly straight flowing,
constrained alternately by it’s own incision
and a gravel road that is used for logging and
by hikers. Large boulders were used to
reduce lateral dynamic processes and to
prevent the river to spread over the narrow
valley floor.
Typical for the Retzbach are sequences of
shallow riffles with fast flowing water and
deep pools where the water is slowly flowing.
Sporadically, high and steep rock walls force
the river to make slight direction changes.
Reach 1/4
7%
1%
Lateral Scour Pool
Rapid
Riffle
Due to heavily constraining
features along this reach, riffle
habitats are very frequent with a
proportion of 92%. Pools are
represented by lateral scour
pools with 7%.
92%
Reach 1/4
11%
1%
6%
1%
10%
Bedrock (rough)
Boulders (large)
16%
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
15%
40%
Even though the substrate
composition is dominated by
coarse classes (cobbles and
coarse gravel with 55%) and
boulders with 11%, there is a
significant deposit of sand with
11%. This input originates mainly
from the gravel road.
Fines
106
6.1
Cover Percentage
36
28
30
24
18
14
13
12
6
0
0
4
2
0
0
Ar
tif
ic
ia
l
S
tr u
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
y
e
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
D
Br
us
h/
W
oo
d
Fi
W
oo
dy
la
m
M
en
to
us
Al
ga
e
0
Fish find cover primarily under boulders, overhanging vegetation, and undercut banks.
70
60
45
50
40
32
29
30
40
35
20
5
5
Canopy >5m high
Canopy >5m high
18%
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
18%
Coniferous
Deciduous
45%
Deciduous
Mixed
None
27%
Mixed
55%
37%
107
6.1
Canopy cover and understory are severely disturbed or absent. Generally, the vegetation is
dominated by deciduous species. The ground cover is characterized by grasses and barren
because of the road.
90
80
70
60
50
40
30
20
10
0
77
60
50
25
20
16
Canopy >5m high
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
Big Trees >0.3m
Percentage
8
9%
45%
Coniferous
Deciduous
Mixed
Mixed
55%
91%
Along the right bank canopy cover is denser than at the left bank. The predominance of
Picea abies is not natural. The understory provides a different picture with a mixed
vegetation of shrubs and saplings with an average cover of 60%. Examining the statistics of
the ground cover, the proportion of herbs, grasses, and forbs with 77% stands out.
108
6.1
Mean Weighting
1.5
1.2
1.1
1
0.9
0.8
0.8
0.6
0.3
0
0
0
0
0
0
0
Pa
Bu
ve
i ld
m
in
gs
en
t /C
le
ar
ed
Lo
R
t
oa
d/
Ra
Pi
il r
pe
oa
s
d
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
R
st
o
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
ity
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The left bank and its surroundings are seriously damaged mainly by 4 human impacts: the
gravel road, trash, riprap, and pastures.
Mean Weighting
1.5
1.2
0.9
0.6
0.3
0.3
0
0
0
0
0
0
0
0
Bu
il d
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
t iv
it y
0.1
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
0
The right bank is not significantly disturbed by human influences and alterations.
109
6.1
6.1.3.4.1
Left bank
As the gravel road runs on the edge of the river bank the left side is significantly affected.
Figure influence also shows that there is a higher influence of trash.
Channel Geometry and Flowability: Dynamic processes are barely possible and restriction of
the river course is restricted. The result is a lack of habitat diversity as illustrated by Figure
58.
from the gravel road. Figure 58 indicates that there is a higher percentage of sand.
The connectivity of water and land is significantly affected, dynamic processes are nearly
absent, and natural structures are sporadically absent.
Heavy alterations of the typical characteristics of the riparian zone are heavily alterated, a
natural development of vegetation does not existent. Canopy cover is sparse - see Figure 60.
Vegetation as buffer zone is nearly absent. The vegetation cover of the surroundings is
significantly disturbed, mainly because of hay field s and pastures (see Figure 62).
Right Bank
Figure 63 shows that there are hardly any human influences along the right bank and its
surroundings.
The summarising parameters of the right bank are natural or only slightly modified.
from the gravel road. Figure 58 indicates that there is a higher percentage of sand.
Undercut banks are present, fish cover is diverse and frequent (see Figure 59).
The vegetation cover of the riparian zone and the surrroundings is insignificantly disturbed.
110
6.2
Reference Conditions and Results Steinpartztalbach (Site 2)
6.2 Steinpartztalbach (Site 2)
The reference condition respectively the general principle of the Steinpartztalbach were
defined with the help of the River Type Region and the Morphological River Type:
River Type Region
The Steinpartztalbach is a water body of the Limestone-Pre-Alps. For the description of the
summarizing parameters see 6.1.1 Reference Conditions.
The Steinpartztalbach is pendulous along the surveyed stretches. In hilly regions already the
upper courses of small creeks (width <5m) are oscillating because the slope is not steep
enough for them to form a straight channel.
A pendulous stream uses the width of the whole valley bottom without creating curves
because the slope is still too steep and there is not enough space for a sinuous or
meandering course (see Figure 4, translated from freiland Umweltconsulting 2001):
“Channel Geometry and Flow Characteristics
The valley floor provides enough space for the river to diverge from the center line of the
valley creating outer bank- and inner bank-like characteristics. The direction of the channel
changes mostly at the flanks of a valley, alluvial fans, and terraces. The bedload transport is
relatively weak.
Riverbed
- varying relief of cross-sections, longitudinal profiles are characterized by riffle-pool
sequences, deep trenches at outer curves, and relatively short riffle stretches. The
depth variance is high
- alternating substrate sizes are dominated by gravel and sand mixed with small stones
and silt which prevail along riffles
- drops over rootstocks
- high width variability (ca. 1:2); outer and inner banks more obvious than in straight
channels
- outer banks: erosions, undercuts, washed out rootstocks, inner banks: gravel and
sand banks
- river vegetation: only pioneer vegetation along inner banks
- vertical to steep outer banks, often erosion and undercuts; typical are “root acclivities”
with free roots because of lateral erosion
- along middle and lower courses the vegetation is dominated by older succession stages Willows (Salix sp.), Black Alder (Alnus glutinosa), Grey Alder (Alnus incana), Ash
(Fraxinus excelsior); high amount of woody debris and vegetation hanging into the water
111
6.2
-
at inner banks flat slopes with typical succession sequences (fringe of herbaceous plants,
followed by pioneer woods, soft wood, and finally hard wood)
substrate mainly gravel; often accumulations in slack water areas
Vegetation
Along a pendulous river the conditions regarding location are similar to those of sinuous
stretches. As the dynamic is lower the characteristics are not as distinctive:
-
-
habitats for pioneer woods
habitats for soft wood (mostly not very broad): Almond Willow (Salix triandra), Common
Osier (Salix viminalis), European Violet-willow (Salix daphnoides), Grey Willow (Salix
cinerea), Black Alder (Alnus glutinosa), Grey Alder (Alnus incana), White Willow (Salix
alba), Crack Willow (Salix fragilis)
humid slope forests dominated by Sycamore Maple (Acer pseudoplatanus) and Ash
(Fraxinus excelsior)
zonal woods of English Oak (Quercus robur) and European Hornbeam (Carpinus
betulus)”
2/1 L
2/1 R
2/2 L
2/2 R
2/3 L
2/3 R
2/4 L
2/4 R
1
1-2
1
1-2
1
1
1-2
1-2
1-2
1-2
1-2
1-2
1-2
1-2
1-2
1-2
1
2
1
2
1
1
2
2
Banks/Riparian Zone
2-3
2-3
1-2
2-3
1-2
2
2
1-2
Vegetation
Surroundings
2-3
2-3
1-2
2-3
2
2-3
2
1-2
Overall Condition
Class
1-2
2
1-2
2
1-2
1-2
1-2
1-2
Channel Geometry
and Flowability
Riverbed
112
6.2
sample reaches.
Site ID
2/1
2/1
2/2
2/2
2/3
2/3
2/4
2/4
Bank
Left
Right
Left
Right
Left
Right
Left
Right
Status NÖMORPH
1-2
2
1-2
2
1-2
1-2
1-2
1-2
Status WFD
1
2
1
2
1
1
1
1
Figure 64: NÖMORPH evaluation of Site 2, Steinpartztalbach.
113
6.2
The adapted figures of the WFD demonstrate that the whole site has a high ecological status
concerning morphology. Exceptions are the right banks of the reaches 2/1 and 2/2 with good
status. According to the NÖMORPH results, no reach has a better status than 1-2 mainly
because of human impacts (gravel road, parking lot, riprap, logging) on banks, acclivities and
the vegetation of the surroundings (see Table 29).
Fish Cover, Vegetation Cover, and Human Influences are displayed for the single sample
reaches.
Table 31: Results of the Physical Habitat Measurements respectively Estimations for
Site 2.
Reach 2/1
Reach 2/2
Reach 2/3
Reach 2/4
0.47
0.25
0.18
0.31
Discharge Estimation (m³s )
0.08
0.05
0.04
0.08
2.75
3.03
2.29
2.33
3.8
4.1
3.4
3.7
0.54
0.50
0.46
1.09
1.7
1.4
1.6
1.2
14
19
19
20
27
51
46
61
49
74
31
60
0
0.17
0
0.08
0.04
0.35
0
0.10
0
0.12
0.09
0.06
4.8
5.8
4.9
6.7
43
52
54
48
Slope Total (%)
34
41
41
45
0.50
0.60
0.60
0.70
Sinuosity
1.1
1.3
1.1
1.1
Mean Canopy Cover Left (%)
83
91
89
80
Mean Canopy Cover Right (%)
67
87
88
93
0.41
1.10
1.71
0.81
0.47
1.16
0.06
0
−1
Flow Velocity Estimation (ms )
−1
Mean Bar Width (m)
114
6.2
•
•
•
•
•
•
Only a few minor undercuts
Hardly any sediment bars
High slope
Greater sinuosity compared to other sites
Dense canopy cover
LWD rare
•
Large Woody Debris
The amount of LWD all/part in bankfull channel is diverse at Site 2. Whereas hardly any LWD
could be found along reach 2/1, the volume is four times higher at reach 2/3. LWD with large
diameter respectively large length is totally absent (see Figure 65).
LWD above bankfull channel is rare/absent at reaches 2/3 and 2/4. At reach 2/2 there is a
greater volume of LWD with medium diameter and medium length (see Figure 66).
2.00
1.80
xdll
xdml
1.60
xdsl
Volume m³
1.40
ldll
0.73
ldml
1.20
ldsl
1.00
mdll
0.80
mdml
mdsl
0.60
0.40
0.20
1.10
0.99
0.18
sdll
0.81
sdml
sdsl
0.23
0.00
Reach 2/1
Reach 2/2
Reach 2/3
Reach 2/4
115
6.2
2.00
1.80
xdll
1.60
xdml
xdsl
Volume m³
1.40
ldll
ldml
1.20
ldsl
1.00
mdll
0.80
mdml
1.04
0.60
mdsl
sdll
0.40
0.18
0.20
sdml
sdsl
0.29
0.00
Reach 2/1
0.12
0.06
Reach 2/2
Reach 2/3
Reach 2/4
•
“Legacy” Trees and Alien Plant Species
Large trees with a DBH between 0.3m and 0.75m and a height of 15-30m are dominating at
Site 2. Again the mixed riparian forest is characterized by large trees of Norway Spruce
(Picea abies), but also deciduous trees. Generally, there is a frequent appearance of
European Beech (Fagus sylvatica). Even poplar is present. The alien plant species
Himalayan Balsam (Impatiens glandulifera) occurred at three transects (see Table 32).
Table 32: Largest visible potential Legacy Tree and Alien Plant Species.
Diameter at Breast
Height (quantity)
Height (quantity)
Mean Distance from
wetted margin (m)
Type (quantity)
Taxonomic Category
(quantity)
Alien Plant Species l+r
bank (quantity)
0 - 0.1m
0.1 - 0.3m
0.3 - 0.75m
0.75 - 2m
>2m
<5m
5 - 15m
15 - 30m
>30m
Coniferous
Deciduous
Picea abies
Pinus sylvestris
Acer pseudoplatanus
Fraxinus excelsior
Fagus sylvatica
Populus sp.
Impatiens glandulifera
4
7
11
11
1
10
3
8
11
11
1
10
3.9
3
3.5
3
6
5
6
6
5
6
9
2
8
1
11
3
2
2
10
1
3
1
1
3
116
6.2
6.2.3.1 Reach 2/1
Generally,
the
Steinpartztalbach
is
characterized by a high slope. In the riverbed
there are numerous boulders of different
sizes. Up the valley runs a gravel road used
for logging transportation, by neighbours, and
by hikers.
Figure 67: Steinpartztalbach, reach 2/1
The river is punctually restrained by riprap
(here on the right bank) to keep it from
destroying the road during floods. As there is
no substrate for trees or shrubs, vegetation
exists only on the ground and is dominated by
grasses.
Figure 68: Steinpartztalbach, reach 2/1
Reach 2/1
3%
3%
1%
Lateral Scour Pool
Plunge Pool
Trench Pool
The habitat composition is
dominated by riffle sections
with 93% that are interrupted
by different types of pools.
Riffle
93%
Reach 2/1
2% 2%
3%
16%
Boulders (large)
27%
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
15%
35%
19% of the substrate are
boulders, 36% cobbles, and
15% coarse gravel. There is
a large amount of fine gravel
with a proportion of 27%.
One major reason is the
gravel road that crosses the
Steinpartztalbach
several
times along its course.
Fines
117
6.2
Cover Percentage
36
31
30
21
24
18
12
6
5
6
0
1
0
1
0
A
rti
fic
ia
l
S
tr u
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
y
e
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
D
Br
us
h/
W
oo
d
Fi
W
oo
dy
la
m
M
en
to
us
Al
ga
e
0
Figure 70: Reach 2/1 - Fish cover
At reach 2/1 fish cover is frequent compared to other sites and reaches because there is a
section overgrown by vegetation. In addition, numerous large and small boulders provide
hiding places.
63
53
30
Canopy >5m high
Herbs/Grasses/Forbs
5
Shrubs/Saplings
Shrubs/Saplings
18
Canopy >5m high
18%
Herbs/Grasses/Forbs
12
Small Trees <0.3m
12
Big Trees >0.3m
Percentage
80
70
60
50
40
30
20
10
0
18%
Deciduous
Mixed
Mixed
None
64%
100%
118
6.2
Along the banks trees are rare. Sporadically there is no canopy cover at all. Instead, the
understory with deciduous and coniferous shrubs and saplings is distinct. Even the ground
cover is dominated by vegetation (herbs, grasses, and forbs).
70
54
60
50
41
40
20
20
10
5
0
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
32
28
30
Canopy >5m high
9%
27%
36%
Coniferous
Deciduous
Deciduous
Mixed
None
55%
73%
Along the right bank and its surroundings there are larger areas without canopy cover
because of the gravel roads and hay fields. Big trees with a DBH >0.3m are absent. The
understory consists mainly of shrubs, saplings, and grasses. Ground cover is primarily
characterized by herbs, grasses, forbs, and barren.
119
6.2
Mean Weighting
1.5
1.2
0.9
1
0.8
0.6
0.8
0.5
0.3
0
0
0
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fil
l/T
ra
sh
P
ar
k/
La
wn
Pa
R
st
ow
ur
e/
C
ro
R
an
ps
ge
/H
ay
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
ity
0
le
ar
ed
ui
ld
in
gs
P
D
ik
av
em
en
t/C
B
e/
Re
ve
tm
en
t /R
ip
ra
p
0
0.3
0.2
0.1
The left bank and its surroundings are affected by several human disturbances and
influences, mainly by trash, gravel roads and buildings: there are two small houses with
access roads. There is also an outlet that leads water to a small pond - from there the water
flows back again into the Steinpartztalbach.
Mean Weighting
1.5
1.2
1.2
0.9
0.8
0.6
0.6
0.3
0
0.4
0
0
0.1
0
Bu
i ld
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
f il
l/ T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
it y
0.3
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
0
Sporadically, the right bank is heavily influenced by the gravel road. Especially where it runs
along the edge of the bank riprap consisting of huge boulders prevents dynamic processes
and a natural forming of the bank and its vegetation. Furthermore, cleared lots and logging
operations disturb the natural development of vegetation.
120
6.2
6.2.3.1.1
Left bank
The left side of the river channel is not significantly influenced by human activities. The
channel geometry and flowability are in natural condition as well as the connectivity of water
and land. Fish cover is frequent, dominated by boulders and overhanging vegetation.
from the gravel road. Figure 69 indicates that there is a higher percentage of fine gravel.
The typical characteristics of the riparian zone are heavily alterated, vegetation cover is
significantly disturbed or absent (see Figure 71). There is only a narrow vegetation buffer
zone.
The vegetation cover of the surroundings is significantly modified, there is are houses with
gardens where non-native species grow (see Figure 73).
Right Bank
The right bank is influenced by a gravel road and riprap as illustrated by Figure 74.
Channel geometry and flowability: The course of the river is sporadically anthropogenic
influenced, but near-natural. Dynamic processes are limited.
from the gravel road. Figure 69 indicates that there is a higher percentage of fine gravel.
The connectivity of water and land is slightly modified, lateral dynamic processes are limited,
and natural structures sporadically absent. Fish cover is represented mainly by boulders,
including riprap (see Figure 70).
The typical characteristics of the banks and the riparian zone are heavily alterated,
vegetation cover significantly disturbed, single non-native species are present (see Figure
72). There is only a narrow vegetation buffer zone.
The vegetation cover of the surroundings is significantly disturbed, there are cleared lots
(see Figure 74) and non-native species.
121
6.2
6.2.3.2 Reach 2/2
There are several human alterations of the
river’s surroundings like gravel roads, a
parking area, a timber store, and logging
activities. Nevertheless, the course of the
river bed itself is natural/near natural because
of its incision into the valley floor.
Figure 75: Steinpartztalbach, reach 2/2.
Especially the right bank is influenced by
human influences. The photo shows the
results of logging operations. The gravel road
runs along the edge of the acclivity. Even
though the whole river is described as
straight, there are pendulous stretches with
direction changes along the surveyed site.
Reach 2/2
1% 3%
5%
1%
Cascade
Glide
Plunge Pool
Trench Pool
This
reach
is
mainly
characterized by riffle sections
with 90%. Pools are not as
frequent as at the other reaches.
Riffle
90%
Reach 2/2
6%
1% 2% 1%
23%
24%
Bedrock (smooth)
Boulders (large)
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
8%
Fines
35%
Whereas the proportion of
cobbles (35%) and boulders
(24%) is high, coarse gravel
plays a minor role. The reason
for the high percentage of fine
gravel and sand (30%) is
supposably the input from the
gravel road.
122
6.2
36
28
Cover Percentage
30
24
16
18
12
7
6
6
0
0
2
0
0
A
rti
fic
ia
l
St
ru
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
e
Li
v
y
Br
us
h/
W
oo
d
D
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
W
oo
dy
Fi
la
m
M
en
to
us
Al
ga
e
0
The distribution of the percentages concerning fish cover resembles that of reach 2/1. A
difference are the higher proportions of undercut banks and brush/woody debris.
90
80
70
60
50
40
30
20
10
0
77
Canopy >5m high
Canopy >5m high
11
10
Herbs/Grasses/Forbs
Shrubs/Saplings
12
Shrubs/Saplings
40
Herbs/Grasses/Forbs
40
Small Trees <0.3m
Big Trees >0.3m
Percentage
39
9%
9%
Coniferous
45%
Deciduous
Deciduous
Mixed
Mixed
46%
91%
123
6.2
The canopy cover on the left bank is dense as the surroundings are covered by a mixed
forest where beech (Fagus sylvatica) is very frequent. The understory is dominated by
shrubs and saplings. The vegetation on the ground consists primarily of grasses.
70
60
50
40
60
41
27
30
20
31
24
23
12
Canopy >5m high
Canopy >5m high
9%
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
Big Trees >0.3m
Percentage
10
0
9%
36%
Deciduous
Mixed
Deciduous
None
Mixed
64%
82%
On the right bank big trees that cover a large area are common. Whereas the understory is
moderately developed, the ground cover is dominated by a vast occurrence of herbs,
grasses, and forbs. Deciduous trees are more frequent as coniferous trees.
124
6.2
Mean Weighting
1.5
1.2
0.9
0.6
0.6
0.3
0
0.2
0.3
0.3
0.2
0.3
0.4
0
0
0
Bu
ild
in
en
gs
t /C
le
ar
ed
Lo
R
t
oa
d/
Ra
Pi
ilr
pe
oa
s
d
( In
le
t/O
ut
le
t)
La
nd
fil
l/T
ra
sh
Pa
rk
/L
aw
n
P
Ro
as
tu
w
re
Cr
/R
op
an
s
ge
/H
ay
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
ity
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The left bank is affected by several human influences of which none is standing out.
Mean Weighting
1.5
1.2
0.9
1
0.6
1
0.7
0.6
0.3
0.3
0
0
0
Pa
ve
m
ip
ra
p
e/
R
ev
et
m
en
t/R
D
ik
0.3
0.1
Bu
i ld
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
it y
0.1
0
The right bank and its surroundings is heavily affected by human disturbances and
influences. The gravel road and logging operations are the dominating impacts followed by
cleared lots and hay fields. Buildings, trash, and riprap are not significant.
125
6.2
6.2.3.2.1
Left bank
Along the left side of the river the condition class of the summarizing parameters is natural or
slightly modified (see Table 29).
Channel geometry and flowability are undisturbed.
from the gravel road. Figure 77 indicates that there is a higher percentage of fine gravel and
sand.
The connectivity of water and land is not modified.
Fish cover is frequent and divers consisiting of boulders, overhanging vegetation, and woody
debris (see Figure 78 and Figure 65).
The riparian zone is affected by minor alterations of the typical characteristics, vegetation
cover is insignificantly disturbed as illustrated by Figure 79 and Figure 81.
Vegetation cover of the surroundings is slightly influenced by a garden, a gravel road,
cleared lots and logging operations.
Right Bank
Channel geometry and flowability are slightly modified because of single alterations. The
development of the river course is near-natural.
from the gravel road. Figure 77 indicates that there is a higher percentage of fine gravel and
sand.
The connection between water and the adjacent area is sporadically restricted, lateral
dynamic processes are limited, and natural structures are sporadically absent.
The riparian zone is affected by minor alterations of the typical characteristics, vegetation
cover is insignificantly disturbed, non-native species are present. There is only a narrow
vegetation buffer zone.
The vegetation cover of the surroundings is significantly disturbed or absent, non-native plant
species are present (see Figure 80).
The influences of the mentioned human influences are illustrated by Figure 82.
126
6.2
6.2.3.3 Reach 2/3
Because of geology and the steep decline the
river dynamics create riffle - plunge pool
sequences interrupted by small cascades.
The ground is covered with grasses, forbs,
and moss.
On the left canopy cover of the surroundings
is interrupted because of logging activities, a
timber store, and a gravel road. A part of the
left bank is also influenced by a gravel road.
Whereas understory vegetation is often
absent, the ground is heavily overgrown.
Reach 2/3
2% 1% 3%
15%
Cascade
5%
Glide
Lateral Scour Pool
Plunge Pool
Rapid
Riffle
74%
Reach 2/3
6%
3%
4%
1% 1%
Bedrock (smooth)
23%
Bedrock (rough)
Boulders (small)
20%
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
Fines
12%
30%
Even if there is a higher
diversity of habitat classes
compared to other surveyed
stretches, riffle sections are still
dominant. Prominent is the
frequency of plunge pools.
Small boulders are frequent
with 23% as well as cobbles
and coarse gravel with 42%.
There are also accumulations
of sand and fines with an
occurrence of 9%. Wood has a
proportion of 4% (see Figure
65).
Wood
127
6.2
Cover Percentage
30
23
24
18
11
10
12
5
6
0
2
1
0
0
Ar
tif
ic
ia
l
S
tr u
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
e
De
br
.<
y
D
eb
ris
Br
us
h/
W
oo
d
W
oo
dy
la
m
Fi
0,
3m
>0
.3
m
ac
ro
ph
yt
es
M
en
to
us
Al
ga
e
0
The distribution of the percentages concerning fish cover is similar to that of reach 2/2. A
main difference is the higher proportion of woody debris with 10%.
77
51
40
Canopy >5m high
Shrubs/Saplings
14
9
Herbs/Grasses/Forbs
6
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
30
Big Trees >0.3m
Percentage
90
80
70
60
50
40
30
20
10
0
Canopy >5m high
9%
45%
Coniferous
Deciduous
Mixed
55%
Mixed
91%
128
6.2
Whereas canopy cover is mixed but with a higher percentage of coniferous species (Picea
abies), the understory vegetation is mixed too, but with a higher percentage of deciduous
species. Small trees, shrubs and saplings are dominant. The ground is heavily overgrown by
herbs, grasses, and forbs.
77
45
41
Canopy >5m high
Shrubs/Saplings
Canopy >5m high
6
10
Herbs/Grasses/Forbs
12
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
29
Big Trees >0.3m
Percentage
90
80
70
60
50
40
30
20
10
0
18%
9%
Coniferous
Deciduous
Mixed
Mixed
73%
100%
Along the right bank the disturbed canopy cover is dominated by big trees with a DBH >0.3m.
The composition of types is mixed with a high percentage of coniferous species. The mixed
understory vegetation consists mainly of woody vegetation. As on the left side, the ground is
heavily overgrown by herbs, grasses, and forbs.
129
6.2
Mean Weighting
1.5
1.2
0.9
0.9
0.9
0.6
0.5
0.3
0
0.3
0
0
0
0
0
0
Bu
il d
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
it y
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
A logging road and recent logging operations are heavily impacting the surroundings along
the left bank
Mean Weighting
1.5
1.2
0.9
0.9
0.8
0.6
0.3
0
0.1
0
0
0.1
0
Bu
il d
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
R
st
o
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
it y
0.2
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t /R
ip
ra
p
0
0.4
0.3
A multitude of human disturbances affect the river and the adjacent area along the right
bank. A major role play gravel roads and cleared lots (timber store, source protection area)
followed by hay fields.
130
6.2
6.2.3.3.1
Left bank
The left bank is not heavily influenced by human impacts (see also Table 29).
Channel Geometry and Flowability are valued with condition class 1. There is a typical pool
riffle sequence with manifold habitats (see Figure 85).
from the gravel road. Figure 85 indicates that there is a higher percentage of fines, sand, and
fine gravel.
The connectivity of water and land is natural. Fish cover is frequent and diverse due to
boulders, overhanging vegetation, large woody debris, and undercut banks. This is also
illustrated by Figure 86 and Figure 65.
The vegetation cover of the riparian zone (see Figure 87) is insignificantly disturbed,
sporadically non-native species are present. The vegetation buffer zone is narrow.
The vegetation cover of the surroundings is significantly disturbed because of lodging
operations, a gravel road, and cleared lots (see Figure 89).
Right Bank
Channel Geometry and Flowability are valued with condition class 1. There is a typical pool
riffle sequence with manifold habitats (see Figure 85).
fine gravel.
The connectivity of water and land is natural. Fish cover is frequent and diverse due to
boulders, overhanging vegetation, large woody debris, and undercut banks. This is also
illustrated by Figure 86 and Figure 65.
The vegetation cover of the riparian zone is significantly disturbed, sporadically non-native
species are present. There is only a narrow vegetation buffer zone.
The vegetation of the surroundings is significantly disturbed. Figure 90 shows that human
influences are mainly caused by a gravel road and cleared lots.
131
6.2
6.2.3.4 Reach 2/4
There are two small bridges crossing the river at
the surveyed site. At the bridges the input of fine
gravel, sand, and fines is higher due to the
absence of a buffer. The bridge on the photo is
made out of concrete that also covers partly the
river bottom. Below the bridge there is a deep pool
with a large accumulation of fine gravel.
Upstream of the bridge are no artificial
structures. Along the right bank the adjacent
area is vegetated by a mixed forest. On the left
bank the vegetation buffer is mixed too, with
sporadically dense understory. Here the gravel
road runs near the left bank.
Reach 2/4
7%
5% 3%
1%
Cascade
5%
1%
Glide
Backwater+Impoundment Pool
3%
Lateral Scour Pool
Plunge Pool
Trench Pool
Even
though
the
percentage of riffle with
75% is high, diverse habitat
classes are found at this
reach such as cascades,
glides, pools, and rapids.
Rapid
75%
Riffle
Reach 2/4
1%
4% 3%
3% 1% 2%
Bedrock (smooth)
18%
19%
Bedrock (rough)
Boulders (large)
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
10%
Sand
39%
Fines
Concrete
Boulders
are
again
frequent with a percentage
of 20%. The proportion of
cobbles is very high
compared to the proportion
of coarse gravel with 10%.
Prominent
is
the
abundance of fine gravel,
sand, and fines with 24%.
Due
to
the
bridge
construction concrete has a
proportion of 3%
132
6.2
Cover Percentage
30
25
24
17
18
10
12
5
6
0
0
2
0
2
Ar
t if
ic
ia
l
S
tr u
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
e
De
br
.<
y
D
eb
ris
Br
us
h/
W
oo
d
W
oo
dy
Fi
la
m
0,
3m
>0
.3
m
ac
ro
ph
yt
es
M
en
to
us
Al
ga
e
0
Compared to other reaches fish cover is frequent with a high percentage of boulders and
overhanging vegetation, followed by brush, woody debris, and undercut banks.
80
70
60
50
40
30
20
10
0
68
48
20
Shrubs/Saplings
10
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
Big Trees >0.3m
Percentage
Canopy >5m high
17
Herbs/Grasses/Forbs
34
23
Canopy >5m high
9%
27%
Coniferous
46%
Deciduous
Deciduous
Mixed
Mixed
None
36%
73%
9%
133
6.2
74
71
38
30
16
Canopy >5m high
Canopy >5m high
18%
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
8
6
Small Trees <0.3m
90
80
70
60
50
40
30
20
10
0
Big Trees >0.3m
Percentage
Along the left bank canopy cover, with a high proportion of coniferous vegetation, is not
distinctive because of the impact of the gravel road. The mixed understory is dominated by
shrubs and saplings. The ground is mainly overgrown with grasses and herbs, as well as
with shrubs and saplings. Barren, bare dirt, or duff are rare.
9%
Deciduous
Mixed
Mixed
None
73%
100%
Whereas the mixed canopy cover is sporadically absent, understory is dense with a high
proportion of deciduous and coniferous shrubs and saplings. Again, ground cover consists
mainly of grasses and herbs.
134
6.2
Mean Weighting
1.5
1.2
1.1
0.9
0.6
0.6
0.3
0.4
0.2
0.3
0.2
0.1
0
0
0
Bu
il d
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
t iv
it y
0
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The main reasons for disturbed conditions are again the gravel road and logging operations.
However, there are also several minor human disturbances and influences such as cleared
lots and pipes that must not be underrated.
Mean Weighting
1.5
1.2
0.9
0.9
0.6
0.3
0.2
0
0
0
0
0
0
0.2
0
Bu
ild
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/ O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
t iv
it y
0.1
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The adjacent area of the right bank is affected by a logging road that runs up the hillside.
135
6.2
6.2.3.4.1
Left bank
The left bank is influenced by different human activities and disturbances as a gravel road,
lodging operations, cleared lots, and a bridge that has a concrete substructure (see Figure
93 and Figure 97 for details).
Channel geometry and flowability are affected by single alterations, the development of the
river course is near-natural. Figure 93 illustrates that there is a high diversity of habitats.
fine gravel.
The connectivity of water and land is sporadically restricted, lateral dynamic processes are
limited, and natural structures are sometimes absent. Fish cover is frequent and diverse due
to boulders, overhanging vegetation, large woody debris, and undercut banks (see Figure 65
and Figure 94).
The typical characteristics of the riparian zone are modified due to minor alterations, the
vegetation cover is significantly disturbed or absent (see Figure 95).
There is only a narrow vegetation buffer zone. The vegetation cover of the surroundings is
significantly disturbed.
Right Bank
The right bank is mainly influenced by a gravel road and a bridge that has a concrete
substructure (see Figure 93 and Figure 98 for details).
river course is near-natural. Figure 93 illustrates that there is a high diversity of habitats.
fine gravel.
limited, and natural structures are sporadically absent. Fish cover is frequent and diverse due
to boulders, overhanging vegetation, large woody debris, and undercut banks (see Figure 65
and Figure 94).
The typical characteristics of the riparian zone are modified due to minor alterations, the
vegetation cover is significantly disturbed or absent (see Figure 96).
The vegetation cover of the surroundings is insignificantly disturbed (see Figure 98), nonnative species are present.
136
6.3
Reference Conditions and Results Ramsaubach (Site 3)
6.3 Ramsaubach (Site 3)
The reference condition respectively the general principle of the Ramsaubach were defined
with the help of the River Type Region and the Morphological River Type:
River Type Region
The Ramsaubach is a water body of the Limestone-Pre-Alps. For the description of the
summarizing parameters see 6.1.1 Reference Conditions.
The morphological river type of the Ramsaubach along the surveyed site is pendulous (see
6.2.1 Reference Conditions).
Table 33: Results of the evaluation of the 5 summarizing parameters -Site 3.
3/1 L
3/1 R
3/2 L
3/2 R
3/3 L
3/3 R
3/4 L
3/4 R
Channel Geometry
and Flowability
2-3
2
1-2
1-2
3
2-3
3
2-3
Riverbed
1-2
1-2
1-2
1-2
1-2
1-2
1-2
1-2
2
2
1-2
1-2
2-3
2
2-3
2-3
Banks/Riparian Zone
2-3
2-3
3
2-3
2-3
3
3
2
Vegetation
Surroundings
2-3
1-2
2-3
2-3
3
2-3
3-4
2
Overall Condition
Class
2-3
2
2
2
2-3
2-3
2-3
2
137
6.3
sample reaches.
Site ID
3/1
3/1
3/2
3/2
3/3
3/3
3/4
3/4
Bank
Left
Right
Left
Right
Left
Right
Left
Right
Status NÖMORPH
2-3
2
2
2
2-3
2-3
2-3
2
Status WFD
2
2
2
2
2
2
2
2
Figure 99: NÖMORPH evaluation of Site 3, Ramsaubach.
The illustration indicates the results of the total evaluation of the NÖMORPH survey for both
banks using the transformed figures of the Water Framework Directive. The green colour
represents condition class 2, turquoise illustrates the location of bypass canals. (Orthophoto
by BEV).
138
6.3
The situation at Site 3 is complex. The surroundings are affected by human disturbances as
agriculture, roads, gravel roads, and bike paths. The channel of the Ramsaubach is heavily
influenced by water withdrawal in a way that the river bottom is temporarily dry downstream
of the outlet at reach 3/3. At Site 3 the same procedures of the survey methods were carried
out for the morphology assessment as for the other sites. Parameters that could not be
evaluated or measured were omitted.
The composite parameters that were in worst condition are channel geometry and flowability,
banks respectively acclivities, and the vegetation of the surroundings. The riverbed itself was
mainly affected concerning substrate class composition. Condition class 2 for the whole site
is the result of the adapted figures of the WFD. According to the NÖMORPH-method reach
3/3 is in worst condition with condition class 2-3 for both banks.
reaches.
Table 35: Results of the physical habitat measurements respectively estimations for
Site 3.
Reach 3/3
Reach 3/4
0.11
0.74
0.96
Discharge Estimation (m³s )
0.03
1.54
1.55
2.51
5.36
6.40
6.4
8.5
8.3
0.65
0.64
0.63
1.6
1.5
1.8
11
29
41
31
30
46
45
28
31
0.10
0
0.05
0
0
0
Mean Bar Width (m)
0
0
0
4.2
1.2
2.1
46
53
45
Slope Total (%)
11
6
5
0.15
0.10
0.10
Sinuosity
1.1
1.1
1.1
73
86
59
Reach 3/1
−1
Flow Velocity Estimation (ms )
−1
Reach 3/2
7.6
58
139
6.3
85
80
70
70
1.23
1.43
0.94
0.47
0
0
0
0.55
•
•
•
•
•
No undercuts
No sediment bars
Small mean substrate diameter at reaches 3/3 and 3/4
Low slope
LWD rare
•
Large Woody Debris
Only LWD with small diameter was found within the bankfull channel. Generally, the volume
of LWD is not prominent, especially along reach 3/4 (see Figure 100).
2.00
1.80
xdll
1.60
xdml
xdsl
Volume m³
1.40
1.20
ldll
0.18
0.44
ldml
ldsl
1.00
mdll
0.18
0.80
0.60
mdml
0.36
mdsl
1.04
sdll
0.81
0.40
0.18
0.58
0.20
0.29
sdml
sdsl
0.00
Reach 3/1
Reach 3/2
Reach 3/3
Reach 3/4
Large woody debris above the bankfull channel is nearly absent at Site 3 (see Figure 101).
140
6.3
2.00
1.80
xdll
xdml
1.60
Volume m³
xdsl
1.40
ldll
1.20
ldml
ldsl
1.00
mdll
0.80
mdml
0.60
mdsl
sdll
0.40
sdml
0.55
0.20
sdsl
0.00
Reach 3/1
Reach 3/2
Reach 3/3
Reach 3/4
•
Legacy Trees and Alien Plant Species
(quantity)
Height (quantity)
Mean Distance from
wetted margin (m)
Type (quantity)
Taxonomic Category
(quantity)
bank (quantity)
0 - 0.1m
0.1 - 0.3m
0.3 - 0.75m
0.75 - 2m
>2m
<5m
5 - 15m
15 - 30m
>30m
Coniferous
Deciduous
Picea abies
Pinus sylvestris
Acer pseudoplatanus
Alnus glutinosa
Carpinus betulus
Fagus sylvatica
Fraxinus excelsior
Fagus sylvatica
Populus sp.
Quercus robur
Salix sp.
Fallopia japonica
2
9
5
6
5
6
2
7
2
1
10
2
9
6
5
11
1.9
0
0.8
9
11
11
11
11
1
1
2
2
2
7
4
1
2
3
6
8
1
4
17
20
21
19
141
6.3
Most “Legacy” trees recorded have a DBH of 0.1-0.3m or 0.3-0.75m. Two trees have a DBH
of 0.75-2m. No “Legacy” tree had a height <5m or >30m.
The mean distance from the wetted margin was not evaluated for reach 3/2 because of the
absence of water. Noticeable is the diversity of the mean distance from the wetted margin
concerning the single reaches: whereas the mean distance is 0.8m at reach 3/3, it is 9m at
reach 3/4.
Along the whole site all “Legacy” trees are deciduous: the most frequent species are willows
(Salix sp.), followed by European Ash (Fraxinus excelsior) and Black Alder (Alnus glutinosa).
Site 3 is heavily affected by an alien plant
species called Japanese Knotweed
(Fallopia japonica) that has overgrown
large areas along reach 3/2 and reach
3/3. Sporadically, there is hardly any
water left in the river during low flow
periods.
Figure 102: Ramsaubach: Alien plant species Fallopia japonica.
142
6.3
6.3.3.1 Reach 3/1
Looking upstream: The channel of the
Ramsaubach coming from the right is nearly
dry due to the water withdrawal upstream.
Water input originates from groundwater and
a sluice constructed to release the bypass
canal during flood events.
Figure 103: Ramsaubach, reach 3/1.
Looking downstream: residual flow reach
characterized by a low flow, boulders and fine
sediments. There is little water in the river bed
because the canal that leads to the small
hydro power station is leaking and the ground
water level is quite high. On the left side runs
a bike path, along the right side of the valley a
main road.
Reach 3/1
2%
24%
Dry
Glide
Lateral Scour Pool
Trench Pool
6%
64%
Riffle
4%
The diversity of the habitat
classes is not as high as along
other sites. At reach 3/1 riffle is
dominant with 64%. The
proportion
of
glides
is
prominent with 24%. Pools
were
recorded
with
an
occurrence of 10%.
Reach 3/1
2% 2% 1%
23%
25%
Hardpan
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
14%
Sand
Coarse gravel is the dominant
substrate class with 33%,
followed by fine gravel with
25%, small boulders with 23%,
and cobbles with 14%.
Fines
33%
143
6.3
Cover Percentage
18
13
11
12
6
4
5
4
0
2
1
0
Ar
t if
ic
ia
l
St
ru
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
ov
er
ha
ng
i
Tr
ee
s/
R
e
Ve
ge
t
at
io
n
Br
us
h/
W
oo
d
Li
v
y
D
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
W
oo
dy
Fi
la
m
M
en
to
us
Al
ga
e
0
Fish cover is present mainly under boulders with 13% and overhanging vegetation with 11%.
Less frequent are live trees/roots with 5%, and brush/woody debris and filamentous algae in
each case with 4%.
70
59
60
50
42
40
30
26
21
11
Canopy >5m high
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
22
19
20
10
18%
Deciduous
Deciduous
None
82%
100%
144
6.3
Because of the bike path and agricultural areas at the edge of the acclivity, there is not a lot
of space for trees to grow. Therefore, the deciduous canopy cover and the understory is
heavily disturbed or absent. Even the ground vegetation is degenerated illustrated by the
high proportion of barren and bare dirt.
70
57
60
50
40
30
40
37
44
33
24
15
20
Canopy >5m high
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
9%
Deciduous
Deciduous
None
91%
100%
At the right bank canopy cover is denser than on the left bank due to deciduous trees that
grow on the steep acclivity. Vegetation of the understory is deciduous as well represented
mainly by shrubs and saplings. On the ground the proportion of bare dirt is high with 57%.
145
6.3
Mean Weighting
1.5
1.4
1.2
0.9
0.8
0.6
0.5
0.3
0.8
0.5
0.3
0
0
0.3
0
0
Bu
i ld
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
f il
l/ T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
it y
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The left bank is heavily affected by human alterations and influences: trash pollutes the bank
and the river bed and there is a high pressure through riprap, cleared lot and a bike path.
Mean Weighting
1.5
1.4
1.2
0.9
0.9
0.6
0.3
0.3
0.3
0.3
0.3
0
0
0
0
0
Bu
ild
in
en
gs
t /C
le
ar
ed
Lo
R
t
oa
d/
Ra
Pi
ilr
pe
oa
s
d
( In
le
t/O
ut
le
t)
La
nd
fil
l/T
ra
sh
Pa
rk
/L
aw
n
P
Ro
as
tu
w
re
Cr
/R
op
an
s
ge
/H
ay
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
ity
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
Trash is also a major problem along the right bank. Other disturbances are the main road
that runs up the valley and riprap.
146
6.3
6.3.3.1.1
Left bank
The condition of most summarizing parameters is classified as slightly modified to heavily
modified (see also Table 33). Figure 109 illustrates the main human disturbances and the
weighting of their influence.
river course is near-natural, flow characteristics are heavily affected, and dynamic processes
are barely possible.
The substrate composition and the riverbed relief are sporadically not typical respectively
disturbed due to the heavily modified discharge conditions.
The connection between water and land is sporadically restricted, lateral dynamic processes
are limited, and natural structures are occasionally absent. Fish cover is frequent and diverse
due to boulders, overhanging vegetation, large woody debris, filamentous algae, and roots
(see Figure 100 and Figure 106).
The characteristics of the left bank and the riparian zone are heavily altered, non-native
species are present (see Table 36). Vegetation cover is significantly disturbed or absent (see
Figure 107). There is only a narrow vegetation buffer zone.
The vegetation of the surroundings is significantly disturbed.
Right Bank
The condition of most summarizing parameters is classified as slightly modified to heavily
modified (see also Table 33). Figure 110 illustrates the main human disturbances and the
weighting of their influence.
river course is near-natural, flow characteristics are affected, and dynamic processes are
limited.
The substrate composition and the riverbed relief are sporadically not typical respectively
disturbed due to the heavily modified discharge conditions.
are limited, and natural structures are occasionally absent. Fish cover is frequent and diverse
due to boulders, overhanging vegetation, large woody debris, filamentous algae, and roots
(see Figure 100 and Figure 106).
The characteristics of the bank and the riparian zone are influenced. The vegetation cover is
significantly disturbed or absent (see also Figure 108) and invasive plant species are
dominating (see Table 36). There is only a narrow vegetation buffer zone.
The vegetation cover of the surroundings is insignificantly disturbed.
147
6.3
6.3.3.2 Reach 3/2
Totally dry river stretch - a few days before
there still had been some pools left and water
had been flowing in between coming from the
ground. The bank vegetation is dominated by
an invasive alien plant species (Fallopia
japonica) which is a typical alien plant species
at this site.
Sporadically, water is seeping through the
porous concrete. Trash, mostly plastic, forms
accumulations when it gets caught up in
branches or woody debris. Large willows are
frequent at this site.
Reach 3/2
1%
As the reach has been nearly dry
during the field work, no habitat
class evaluation is possible.
5%
Dry
Lateral Scour Pool
Riffle
94%
Substrate
composition
is
dominated by coarse and fine
gravel, followed by cobbles.
Boulders are very rare.
Figure 113: Reach 3/2 - Habitat classes.
Fish cover could not be assessed due to the absence of water.
148
6.3
70
60
57
52
50
35
40
30
20
34
17
11
2
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
Canopy >5m high
9%
9%
Deciduous
Deciduous
None
None
91%
91%
Whereas canopy cover is not heavy and often absent at the left bank, cover of the
understory, that consists mainly of herbs, grasses, and forbs, is sporadically very dense.
Both vegetation layers are composed mainly of deciduous vegetation types. Ground cover is
dominated by bare dirt followed by grasses and forbs.
149
80
70
60
50
40
30
20
10
0
65
60
57
27
17
16
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Big Trees >0.3m
Percentage
8
Small Trees <0.3m
6.3
Canopy >5m high
9%
Deciduous
Deciduous
Mixed
91%
100%
The canopy cover is composed primarily by small deciduous trees. The understory is
sporadically mixed because of planted Picea abies. The alien plant species Fallopia japonica
covers large areas of the right bank. On the ground bare dirt is common.
Mean Weighting
1.5
1.2
0.9
1.1
1
0.6
0.6
0.3
0
0
0
0.3
0
0
Bu
ild
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
it y
0.1
Pa
ve
m
D
ik
e/
R
ev
et
m
en
t/R
ip
ra
p
0
0.3
150
6.3
The left bank and its surroundings are heavily influenced by trash and cleared lots. An
asphalted bike path that passes through the valley crosses the Ramsaubach several times
and sporadically runs directly on the edge of the river bank.
Mean Weighting
1.5
1.2
1.2
0.9
0.8
0.6
0.3
0.3
0.1
0
0
0
0
0
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
0.1
Bu
ild
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
it y
0.1
On the right bank the major human influences and impacts are trash and the main road.
6.3.3.2.1
Left bank
As the channel was dry during the field survey (see Figure 113)., the assessment was
carried out with the help of an imagined mean discharge.
Flow characteristics slightly differ from the natural status, dynamic processes are limited.
Sporadically, the substrate composition is not typical respectively disturbed due to the
heavily modified discharge conditions.
are slightly limited.
The characteristics of the bank and the riparian zone are influenced. Vegetation cover is
heavily disturbed because of human impacts, invasive plant species are dominating (see
also Figure 114 and Figure 116). The result of the evaluation for the banks was condition
class 3 (heavily modified). There is only a narrow vegetation buffer zone.
The vegetation of the surroundings is significantly disturbed mainly by cleared lots and a
road, non-native species are present (see Figure 116 and Table 36).
151
6.3
Right Bank
Flow characteristics slightly differ from the natural status, dynamic processes are limited.
heavily modified discharge conditions (see Figure 113).
are slightly limited.
The characteristics of the bank and the riparian zone are influenced. Vegetation cover is
significantly disturbed because of human impacts, invasive plant species are dominating (see
also Figure 115 and Figure 117). There is only a narrow vegetation buffer zone.
The vegetation of the surroundings is significantly disturbed by a road and cleared lots, nonnative species are present (see Figure 117 and Table 36).
152
6.3
6.3.3.3 Reach 3/3
A small concrete dam impounds the water
that flows into a bypass canal. The canal runs
parallel to the river and then through a hill to a
small
hydropower
station.
As
the
constructions along the canal are sporadically
porous, water is seeping back into the river
channel. During low flow periods there is no
water flowing over the impoundment
structure.
Compared to other sites the water flow is
uniform and the slope is low along this
stretch. On the left bank there is a vegetated
dike, behind it the bike path and agricultural
areas. On the right bank runs the main road
behind willows that are common at this site.
Reach 3/3
33%
Glide
Lateral Scour Pool
Plunge Pool
53%
Riffle
As the water is mostly deep and
uniformly flowing glides are very
frequent with a proportion of
53% as well as riffles with 33%.
Prominent is the occurrence of
lateral scour pools with 12%.
2%
12%
Reach 3/3
10%
7%
3% 1%
4%
5%
Hardpan
11%
Boulders (large)
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
30%
29%
Substrate classes are divers with
a secondary percentage of large
diameter classes. Gravel is
dominating: fine gravel with 30%
and coarse gravel with 29%.
Noticeable is the proportion of
sand with 7% and fines with
10%.
Fines
Other
153
6.3
Cover Percentage
30
23
24
18
12
9
7
7
6
0
0
0
2
0
Ar
tif
ic
ia
l
S
tr u
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
y
e
De
br
.<
eb
ris
D
Br
us
h/
W
oo
d
W
oo
dy
la
m
Fi
0,
3m
>0
.3
m
ac
ro
ph
yt
es
M
en
to
us
Al
ga
e
0
Generally, fish cover is not common. Overhanging vegetation was the most recorded cover
class, followed by live trees, roots, boulders, and woody debris.
70
60
60
50
40
30
51
42
43
29
24
14
20
Canopy >5m high
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
Big Trees >0.3m
Percentage
10
0
9%
Deciduous
Deciduous
Mixed
91%
100%
154
6.3
Canopy cover and understory cover are mixed. Whereas canopy cover is dominated by small
trees, understory is equally composed by shrubs and saplings as by herbs, grasses, and
forbs. The ground is not heavily vegetated and mostly covered by bare dirt and duff.
70
60
53
50
40
30
28
21
Canopy >5m high
Shrubs/Saplings
Shrubs/Saplings
Canopy >5m high
Herbs/Grasses/Forbs
8
Herbs/Grasses/Forbs
14
Small Trees <0.3m
Percentage
10
0
30
Big Trees >0.3m
30
20
9%
18%
Deciduous
Deciduous
None
Mixed
82%
91%
Due to the main road canopy cover is rare or sporadically absent along the right bank and is
deciduous. Understory is not dense as well with mostly deciduous vegetation and single
coniferous plants. Ground cover has a high proportion of barren, bare dirt, and duff.
155
6.3
1.5
Mean Weighting
1.5
1.2
0.9
0.6
0.8
0.7
0.3
0.4
0.8
0.4
0
0
0
0
0
Bu
il d
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
R
st
o
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
it y
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t /R
ip
ra
p
0
The left bank and its surroundings are heavily affected by trash. A multitude of other human
disturbances and impacts have a high percentage too: the bike path, agricultural areas. Even
though settlements are not dense at the surveyed site, they have an adverse affect on the
Ramsaubach.
1.5
Mean Weighting
1.5
1.4
1.2
1.1
0.9
1
0.6
0.6
0.3
0.4
0
0
0
0
0
Bu
il d
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
t iv
it y
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The right bank is heavily influenced by trash and cleared lots as well as by revetment and the
main road. Sporadically, the bank is used by neighbors as parking place or for leisure time
activities.
156
6.3
6.3.3.3.1
Left bank
As the channel was partly dry during the field survey (see Figure 120), the assessment was
carried out with the help of an imagined mean discharge.
The river course is significantly disturbed, flow characteristics differ from the natural status,
dynamic processes are limited.
heavily modified discharge conditions. Figure 120 indicates a high percentage of fines, sand,
and fine gravel.
The connection between water and land is restricted, lateral dynamic processes are barely
possible due to a dike (see Figure 124). Natural structures are sporadically absent.
The characteristics of the bank and the riparian zone are heavily influenced caused by the
disturbed vegetation cover and invasive plant species (see Table 36).
The vegetation cover of the surroundings is significantly disturbed due to agricultural landuse
and roads (see Figure 124), invasive plant species are dominating.
Right Bank
The right bank and the adjacent area are affected by divers human disturbances with heavy
influences such as riprap, cleared lots, and a road (see also Figure 125).
The river course is significantly disturbed, flow characteristics heavily differ from the natural
status, and dynamic processes are limited (see also Figure 120).
Substrate composition is significantly disturbed due to the heavily modified discharge
conditions. Figure 120 indicates a high percentage of fines, sand, and fine gravel.
The connection between water and land is restricted and lateral dynamic processes are
limited. Natural structures are sporadically absent.
The characteristics of the bank and the riparian zone are heavily influenced, vegetation cover
is heavily disturbed or sparse (see Figure 123) as a buffer zone is barely developed. Invasive
plant species are present.
The vegetation cover of the surroundings is disturbed or absent, invasive plant species are
frequent.
157
6.3
6.3.3.4 Reach 3/4
Looking downstream: reach 3/4 is a residual
water stretch, constrained by overgrown
riprap on the left bank. Sporadically, there is
riprap on the right bank. A new bike path
follows the course of the stream on the edge
of the left bank.
Looking upstream: the adjacent area of the
right bank is covered with mixed forest. There
is a narrow vegetation buffer on the left side
where Fallopia japonica is very common. The
water flow is uniform and rapid.
Reach 3/4
28%
Glide
Lateral Scour Pool
Riffle
Even though riffles are more
frequent than at reach 3/3, the
proportion of glides is high with
28%. Pools, represented by
lateral pools, are rare with 6%.
6%
66%
Reach 3/4
1%
6%
3%
13%
7%
Hardpan
6%
Boulders (large)
Boulders (small)
2%
Cobbles
Gravel (coarse)
Gravel (fine)
22%
Sand
Fines
20%
Substrate composition is very
diverse dominated by a mixture
of coarse and fine gravel and
cobbles. Boulders have a
proportion of 13%. Noticeable is
the proportion of fines with 13%.
“Other”
substrate
means
concrete and revetment other
the bridge (see Figure 126).
Wood
20%
Other
158
6.3
Cover Percentage
24
18
18
10
12
4
6
4
0
5
3
2
0
Ar
t if
ic
ia
l
St
ru
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
y
e
De
br
.<
eb
ris
D
Br
us
h/
W
oo
d
W
oo
dy
Fi
la
m
0,
3m
>0
.3
m
ac
ro
ph
yt
es
M
en
to
us
Al
ga
e
0
Especially on the right bank fish find cover under overhanging vegetation. Live trees and
roots are not very common. Woody debris, filamentous algae, undercut banks, and boulders
are existent but rare. Even artificial structures can be used as fish cover.
60
48
50
39
40
36
30
24
20
6
Canopy >5m high
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
16
14
9%
Deciduous
Deciduous
None
91%
100%
159
6.3
Canopy cover is deciduous and dominated by small trees with a DBH <0.3m. At some
transects it was absent. The understory is not dense and deciduous along the whole reach.
Frequent are grasses and forbs. The ground is not heavily vegetated: the proportion of
barren and bare dirt is high.
38
Canopy >5m high
24
Shrubs/Saplings
Shrubs/Saplings
Small Trees <0.3m
Big Trees >0.3m
Percentage
23
32
30
27
Herbs/Grasses/Forbs
38
Herbs/Grasses/Forbs
50
45
40
35
30
25
20
15
10
5
0
Canopy >5m high
9%
9%
Deciduous
18%
Deciduous
Mixed
Mixed
None
36%
None
55%
73%
At the right bank canopy cover is sporadically absent but dense where existent. Deciduous
and coniferous small trees are more frequent than big trees. The understory is dominated by
deciduous species, mainly shrubs and saplings. The ground cover is mixed: vegetation is
more common than at the other reaches of site 3.
160
6.3
Mean Weighting
1.5
1.2
1.2
0.9
1.1
1
0.9
0.8
0.6
0.7
0.5
0.3
0
0
0
0
Bu
il d
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
ity
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The main human influences are the bike path, trash, and riprap/revetment. At the bridge are
drainage-pipes under the road. There are no buildings directly at the river but they are
affecting the adjacent area as well as cleared lots and agricultural areas.
1.5
Mean Weighting
1.2
0.9
1
0.6
0.7
0.6
0.3
0.7
0.3
0.2
0
0
0
0
0
ct
iv
ity
M
in
i
ng
A
tio
ns
d
O
pe
ra
ay
Lo
Pa
s
tu
gg
in
g
/H
re
/R
an
ge
Ro
w
C
ro
Fi
el
ps
La
w
n
Pa
r
La
nd
f
k/
as
h
t)
ill /
Tr
ut
le
d
/O
Pi
pe
s
( In
le
t
d/
R
R
oa
re
d
/C
le
a
en
t
ai
lro
a
Lo
t
s
ng
ld
i
Bu
i
Pa
ve
m
Di
ke
/
R
ev
et
m
en
t/ R
ip
ra
p
0
The right bank is not as heavily influenced: trash, cleared lots, the main road and
riprap/revetment are the major human impacts.
161
6.3
6.3.3.4.1
Left bank
The left bank and the surroundings are heavily influenced by human alterations. Figure 132
illustrates the major disturbances: Riprap, roads, and agricultural landuse. This leads to the
worst condition classes at Site 3 (see also Table 33).
The river course is significantly disturbed, flow characteristics slightly differ from the natural
status, and dynamic processes are barely possible. Figure 128 indicates a lack of habitat
diversity .
The condition of the substrate composition and the riverbed relief is sporadically not typical
respectively disturbed which is also apparent from Figure 128: There is a high percentage of
fines and fine gravel.
The connectivity of water and land is significantly restricted, lateral dynamic processes are
barely possible, and natural structures are sporadically absent due to riprap (see Figure
132). Overhanging vegetation as fish cover is frequent, undercut banks are rare (see Figure
129).
The characteristics of bank and riparian zone are heavily influenced. Vegetation cover is
significantly disturbed or absent - see Figure 130. Invasive plant species are dominating (see
Table 36). A vegetation buffer zone is barely existent.
The vegetation of the surroundings is heavily disturbed or absent, invasive plant species are
dominating.
Right Bank
The right bank and its surroundings are not as heavily influenced by human alterations as the
left bank (see Figure 133).
Nevertheless, parts of the river course are significantly disturbed, the flow characteristics
slightly differ from the natural status, and dynamic processes are barely possible.
The condition of the substrate composition and the riverbed relief is sporadically not typical
respectively disturbed which is also apparent from Figure 128: There is a high percentage of
fines and fine gravel.
The connectivity of water and land is significantly restricted, lateral dynamic processes are
barely possible, and natural structures are sporadically absent due to riprap (see Figure
133). Overhanging vegetation as fish cover is frequent, undercut banks are rare (see Figure
129).
The characteristics of the bank and the riparian zone are slightly influenced, vegetation cover
is sporadically disturbed or absent (see Figure 131), non-native plant species are present.
The vegetation buffer zone is narrow.
Vegetation cover of the surroundings is insignificantly disturbed, non-native plant species are
present.
162
6.4
Reference Conditions and Results Kreisbach (Site 4)
6.4 Kreisbach (Site 4)
The reference condition respectively the general principle of the Kreisbach were defined with
the help of the River Type Region and the Morphological River Type:
River Type Region
The Kreisbach is a water body of the Flysch- and Sandstone-Pre-Alps (see Figure 2) for
which the summarizing parameters are described as follows (translated from freiland
Umweltconsulting 2001):
“Riverbed
Characterization Upper Course: Broad channel despite low flow; fine loose gravel; partial frail
Flysch- and Sandstone- Bedrock. In wooded regions accumulations of undecomposed
anorganic material on the river bottom. Minor variability of depth because of substrate.
In V-shaped valleys the dominant substrates sizes are Makro- and Mesolithal (see Appendix
B); at cut banks only fine substrate can be found.
The banks with adjacent steep wooded hillsides are partially formed by bedrock bare of
vegetation.
Vegetation
Willows (Salix sp.), Black Alder (Alnus glutinosa), Ash (Fraxinus excelsior); Beech woods
(Fagus sylvatica) on the hillsides. The thick Beech vegetation partially reaches down to the
stream and causes a weak herbaceous understory on the banks.”
The morphological river type of the Kreisbach and the Münichwaldgraben at the sample
reaches is constrained (see 6.1.1 Reference Conditions).
163
6.4
4/1 L
4/1 R
4/2 L
4/2 R
4/3 L
4/3 R
4/4 L
4/4 R
1
1
2-3
2-3
1-2
2
2
1-2
1-2
1-2
2-3
2
1-2
2
1-2
1-2
2
2
2
2
2
2
1-2
1
Banks/Riparian Zone
1-2
1-2
2-3
2-3
2
2-3
2-3
2
2
1-2
3
3-4
2
3
3
3-4
1-2
1-2
2-3
2-3
2
2-3
2
2
Channel Geometry
and Flowability
Riverbed
Vegetation
Surroundings
Overall Condition
Class
sample reaches.
Site ID
4/1
4/1
4/2
4/2
4/3
4/3
4/4
4/4
Bank
Left
Right
Left
Right
Left
Right
Left
Right
Status NÖMORPH
1-2
1-2
2-3
2-3
2
2-3
2
2
Status WFD
1
1
2
2
2
2
2
2
164
6.4
Figure 134: NÖMORPH evaluation of Site 4, Kreisbach.
Reach 4/1 is situated upstream of the mouth of the Münichwaldgraben that is a left tributary
of the Kreisbach . The ecological status of this reach is high according to the adapted figures
of the WFD.
The other reaches are in worse condition but the ecological status is still good. Diverse
human impacts affect the Kreisbach, its banks, and its surroundings. At the surveyed site
human influences are buffered to a certain degree because of the rivers incision into the
valley bottom and riparian vegetation.
165
6.4
reaches.
Table 39: Results of the Physical Habitat Measurements respectively Estimations for
Site 4.
Reach 4/1
Reach 4/2
Reach 4/3
Reach 4/4
Flow Velocity Estimation (ms−1)
0.23
0.07
0.33
0.2
Discharge Estimation (m³s−1)
0.01
0.02
0.1
0.09
2.16
3.71
4.87
4.43
5.2
5.4
9.6
7.1
0.48
0.48
0.55
0.5
4
3.6
2.7
3.5
15
18
28
24
28
37
26
29
23
22
20
18
0
0.04
0
0.04
0
0
0
0
Mean Bar Width (m)
0.08
0.18
0.25
0.14
6.7
9.9
2
3.1
61
68
64
38
Slope Total (%)
39
12
26
10
0.60
0.20
0.40
0.15
Sinuosity
1.1
1
1.1
1.1
94
73
65
70
92
81
66
64
0.24
1.14
0.06
0.23
0
0
0
0.24
• Low flow velocity
• Large incision heights compared to the other sites
• Undercuts nearly absent
• Sediment bars are rare
• Mean substrate diameter not uniform
• High slope at reach 4/1
• Canopy cover heavy along reach 4/1
• LWD rare
166
6.4
•
Large Woody Debris
Generally, LWD all/part in bankfull channel is very rare at Site 4. All LWD recorded belongs
to the sdsl-class or the sdml-class. Most LWD was found along reach 4/2 (see Figure 135).
Above bankfull channel large woody debris is only present at reach 4/4 but even here it is
very rare (see Figure 136).
1.50
xdll
xdml
1.20
xdsl
Volume m³
ldll
ldml
0.90
ldsl
mdll
0.91
0.60
mdml
mdsl
sdll
0.30
sdml
0.18
0.00
0.23
0.06
Reach 4/1
0.23
sdsl
0.06
Reach 4/2
Reach 4/3
Reach 4/4
1.00
0.90
xdll
0.80
xdml
xdsl
Volume m³
0.70
ldll
ldml
0.60
ldsl
0.50
mdll
0.40
mdml
0.30
mdsl
sdll
0.20
0.18
sdml
sdsl
0.10
0.06
0.00
Reach 4/1
Reach 4/2
Reach 4/3
Reach 4/4
167
6.4
•
Legacy Trees and Alien Plant Species
At reach 4/1 (Münichwaldgraben) most “Legacy” trees are deciduous mainly with a DBH of
0.1-0.3m and a height between 15m and 30m. The dominant species is sycamore maple
(Acer pseudoplatanus). Alien plant species are absent.
Along the assessed reaches of the Kreisbach recorded “Legacy” trees are diverse
concerning DBH and height but also dominated by deciduous species as sycamore maple
(Acer pseudoplatanus), willows ( Salix sp.), and pedunculate oak (Quercus robur).
At reaches 4/3 and 4/4 the following alien plant species were found: Japanese Knotweed
(Fallopia japonica), Himalayan Balsam (Impatiens glandulifera), and a Thuja hedge (see
Table 40).
Diameter at Breast
Height (quantity)
Height (quantity)
Mean Distance from
wetted margin (m)
Type (quantity)
Taxonomic Category
(quantity)
bank (quantity)
0-0.1m
0.1 - 0.3m
0.3- 0.75m
0.75 - 2m
>2m
<5m
5 - 15m
15 - 30m
>30m
Coniferous
Deciduous
Abies alba
Picea abies
Pinus sylvestris
Acer pseudoplatanus
Alnus glutinosa
Alnus incana
Betula pendula
Carpinus betulus
Fagus sylvatica
Fraxinus excelsior
Populus alba
Quercus robur
Salix sp.
Fallopia japonica
Impatiens glandulifera
Thuja (hedge)
10
1
3
8
2
9
5
6
3
8
5
6
2
9
6
3
2
4.6
4
6.4
4.6
2
9
1
10
1
2
9
2
1
10
2
4
1
1
7
1
1
1
1
1
1
1
1
1
1
2
3
1
1
2
5
6
1
1
5
3
2
168
6.4
6.4.3.1 Reach 4/1
The creek created a small narrow V-shaped
valley with steep slopes that is a few meters
deep. The vegetation is mainly deciduous
dominated by sycamore maple (Acer
pseudoplatanus). The valley bottom is
covered with bed load substrate.
An artificial sill, not very high but overflown by
very shallow water, disrupts the river
continuum.
Figure 137: Münichwaldgraben, reach 4/1.
At the upper part of the reach the small river flows
over a sequence of cascades and deep plunge pools.
Here bedrock and gravel are the dominating
substrate classes.
Amongst others, the vegetated hillslopes serve also
as a buffer zone against the agricultural landuse at
the edge of the narrow valley.
Figure 138: Münichwaldgraben, reach 4/1.
Reach 4/1
3%
24%
Cascade
Glide
Lateral Scour Pool
Plunge Pool
3%
58%
Trench Pool
Riffle
7%
The diversity of habitats is higher
than at other surveyed reaches.
Again the proportion of riffle is
prominent with 58%, followed by
glides with 24%, and pools with
15%.
5%
Reach 4/1
7%
9%
14%
Bedrock (smooth)
2%
3%
6%
Bedrock (rough)
Boulders (large)
Boulders (small)
Cobbles
Gravel (coarse)
37%
Gravel (fine)
22%
Fines
Coarse gravel is very common
with 37% as well as cobbles with
22%. Compared to other sites
the percentage of bedrock with
16% and of fines with 9% is
noticeable. Fine gravel and
boulders are rare.
169
6.4
3
3
2
1
1
1
1
0
0
St
ru
ct
ur
es
an
ks
<1
m
V
eg
et
at
io
n
A
Un
de
rc
ut
B
ng
oo
ts
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
y
e
De
br
.<
0,
3m
>0
.3
m
eb
ris
D
W
oo
dy
Br
us
h/
W
oo
d
M
ac
ro
ph
yt
es
Al
ga
e
en
to
us
la
m
Fi
0
ia
l
0
rti
fic
0
0
Bo
ul
de
rs
Cover Percentage
4
Fish cover is nearly absent along reach 4/1.
100
88
85
80
60
40
24
13
20
5
0
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
0
Canopy >5m high
36%
45%
Deciduous
Deciduous
Mixed
55%
Mixed
64%
170
6.4
Whereas canopy cover, represented by small trees with a DBH <0.3m, is dense, understory
is nearly absent consisting of shrubs and saplings. The vegetation of both layers is mixed deciduous and coniferous. The ground is mostly unvegetated dominated by bare dirt and
duff.
77
75
33
16
3
14
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
90
80
70
60
50
40
30
20
10
0
Canopy >5m high
18%
27%
Deciduous
Deciduous
Mixed
Mixed
82%
73%
The situation on the right bank is similar to the left bank: small trees are dominating canopy
cover and understory is rare. Different is the higher proportion of deciduous vegetation in
both layers. The mostly unvegetated ground is also dominated by bare dirt and duff.
171
6.4
Mean Weighting
1.5
1.2
0.9
0.8
0.6
0.7
0.6
0.3
0.3
0
0
0
0
0
0
0
Bu
ild
in
en
gs
t /C
le
ar
ed
Lo
R
t
oa
d/
Ra
Pi
ilr
pe
oa
s
d
( In
le
t/O
ut
le
t)
La
nd
fil
l/T
ra
sh
Pa
rk
/L
aw
n
P
Ro
as
tu
w
re
Cr
/R
op
an
s
ge
/H
ay
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
ity
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
Human influences on the banks and the surroundings derive from agricultural land use,
buildings, trash, and revetment.
Mean Weighting
1.5
1.2
0.9
1
0.6
0.7
0.3
0.9
0.7
0.4
0
0
0
0
0
0
Bu
ild
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
it y
Pa
ve
m
D
ik
e/
R
ev
et
m
en
t/R
ip
ra
p
0
Along the right river bank the kinds of human influences and their extent are similar to those
on the right bank. Additionally, a road is affecting the surroundings.
172
6.4
6.4.3.1.1
Left bank
Figure 143 indicates that there are no heavy human influences directly along the left side of
the Münichwaldgraben.
Channel geometry and flowability are nearly unaffected. Figure 139 illustrates that there is a
high habitat diversity.
The riverbed relief and the hyporheic interstitial are sporadically disturbed due to a sill and
revetment at the confluence with the Kreisbach.
limited, natural structures are occasionally absent.
The characteristics of the bank and the riparian zone are only slightly influenced. Canopy
cover is dense, consisting mainly of small trees (see Figure 141).
The vegetation cover of the surroundings is significantly disturbed due to settlements and
agricultural landuse (see Figure 143).
Right Bank
Figure 144 indicates that there are no heavy human influences directly along the right side of
the Münichwaldgraben.
Channel geometry and flowability are nearly unaffected. Figure 139 illustrates that there is a
high habitat diversity.
The riverbed relief and the hyporheic interstitial are sporadically disturbed due to a sill and
revetment at the confluence with the Kreisbach.
limited, natural structures are occasionally absent.
The characteristics of the bank and the riparian zone are only slightly influenced. Canopy
cover is dense, consisting mainly of small trees (see Figure 142). A reduced vegetation
buffer zone does exist.
The vegetation cover of the surroundings is disturbed due to a house, agricultural landuse,
and a road (see Figure 144).
173
6.4
6.4.3.2 Reach 4/2
Looking upstream: downstream of the bridge
the river bottom is paved with huge boulders
vegetated with filamentous algae. Canopy
cover is sparse as well as understory. The
ground is mainly overgrown with grasses. The
slope is low and the slow flow is uniform.
Figure 145: Kreisbach, reach 4/2.
The transverse structure in the background is
about 3m high and makes migration for
organisms impossible. In addition, it retains a
lot of bed load. In sections, the Kreisbach
has incised down to bedrock. Due to the lack
of soil vegetation is rare along the wetted
margin.
Reach 4/2
1%
24%
Cascade
Glide
Lateral Scour Pool
4%
Plunge Pool
Trench Pool
1%
3%
67%
Riffle
Reach 4/2
2%
9%
1%
4%
Bedrock (smooth)
2%
Bedrock (rough)
22%
12%
Boulders (large)
Boulders (small)
Cobbles
Gravel (coarse)
Gravel (fine)
10%
Sand
17%
21%
The diversity of habitat classes
is not high: riffle has a high
proportion with 67%, followed
by glides with 24%. Pools are
rare with 8%.
Fines
Concrete
The substrate composition is
dominated by large substrate
classes: boulders with 39%
and cobbles with 21%. Gravel
is rare compared to other
reaches.
Fines
have
a
proportion of 9%. Under the
bridge concrete covers a part
of the river bottom. Bed rock
was recorded downstream of
the transverse structure.
174
6.4
Cover Percentage
48
37
40
32
24
16
8
0
0
0
4
0
4
1
0
Ar
tif
ic
ia
l
S
tr u
ct
ur
es
Bo
ul
de
rs
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
Li
v
y
e
eb
ris
De
br
.<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
D
Br
us
h/
W
oo
d
Fi
W
oo
dy
la
m
M
en
to
us
Al
ga
e
0
Except filamentous algae that are covering the river bottom downstream of the bridge, fish
cover is nearly absent.
70
60
50
62
60
40
30
25
18
18
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Shrubs/Saplings
Small Trees <0.3m
10
0
Herbs/Grasses/Forbs
9
Big Trees >0.3m
Percentage
30
20
Canopy >5m high
27%
36%
Deciduous
Deciduous
Mixed
Mixed
64%
73%
175
6.4
Sporadically, canopy cover is dense along the left bank. Deciduous trees with a DBH <0.3m
are common. Understory vegetation is often sparse, dominated by deciduous and coniferous
shrubs and saplings. Large areas of the ground are not covered with vegetation.
70
60
53
46
50
40
30
20
32
15
14
4
10
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
29
Canopy >5m high
45%
Deciduous
Deciduous
Mixed
55%
100%
At the right bank, canopy cover mainly consists of small deciduous trees whereas the
understory is mixed where existent with a high proportion of shrubs and saplings. The ground
is also mostly bare overgrown with grasses.
176
6.4
Mean Weighting
1.5
1.2
1.1
0.9
0.8
0.6
0.7
0.7
0.3
0.4
0.4
0.4
0
0
0
0
Bu
il d
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
tiv
it y
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
Primarily, the left bank and its surroundings are influenced by trash, revetment,buildings, and
agricultural areas.
Mean Weighting
1.5
1.2
1.2
1.1
0.9
1
0.8
0.6
0.3
0.4
0
0.4
0
0.2
0
0
Bu
il d
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
R
st
o
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
tiv
it y
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t /R
ip
ra
p
0
Along the right bank the Kreisbach is mainly disturbed by trash and revetment. The main
road that runs through the valley, buildings, and agricultural landuse affect the adjacent area.
177
6.4
6.4.3.2.1
Left bank
The course of the river is influenced by human activities but near-natural. The flow
characteristics differ from the natural status, dynamic processes are limited due to riprap.
The substrate composition and the riverbed relief are significantly disturbed, the hyporheic
interstitial is partly modified. Figure 147 indicates that there is a high percentage of fines.
The connection between water and land is sporadically restricted and lateral dynamic
processes are limited.
The characteristics of the bank and the riparian zone are occasionally influenced - by riprap
and the substructure of a bridge. The vegetation cover is significantly disturbed where a
buffer zone is absent or narrow which is caused by human alterations.
The vegetation of the surroundings is heavily disturbed because of buildings, roads, and
Right Bank
The right bank and its surroundings are partly heavily influenced by human disturbances as
illustrated by Figure 152.
Whereas the course of the river is affected but near-natural, the flow characteristics
significantly differ from the natural status. Dynamic processes are limited.
There are small scale alterations of the substrate composition and the riverbed relief, the
hyporheic interstitial is partly modified. Figure 147 indicates that there is a high percentage of
fines.
processes are limited.
The characteristics of the bank and the riparian zone are occasionally influenced - by riprap
and the substructure of a bridge. The vegetation cover is significantly disturbed where a
buffer zone is absent or narrow which is caused by human alterations like the road running
along the edge of the deeply incised river.
The vegetation of the surroundings is heavily disturbed because of buildings, roads, and
178
6.4
6.4.3.3 Reach 4/3
At the end of reach 4/3 a massive transverse
structure is interrupting the river continuum.
The slope break reduces flow velocity and
and dynamic processes. Furthermore, It
prevents the migration of organisms and
disturbs bed load transport. There is a large
accumulation of cobbles and coarse gravel
upstream of the structure.
Where the river is not straightened and has
enough space it moves between the
constraining slopes, forming a sequence of
sediment banks and undercuts. On the edge
of the terrace on the right runs the main street
that connects the inhabitants of the valley with
the Traisen valley.
Reach 4/3
1%
29%
Cascade
42%
Glide
Impoundment Pool
Lateral Scour Pool
Trench Pool
Riffle
3%
11%
14%
Habitat
composition is
dominated by riffles with
42% and glides with 29%.
Pools
are
frequent,
represented primarily by
trench pools and lateral
scour pools with a total of
25%.
Reach 4/3
16%
1% 1%
7%
Boulders (small)
1%
Cobbles
8%
Gravel (coarse)
Gravel (fine)
Sand
41%
Fines
Concrete
25%
Other
Cobbles are very frequent
with 41%, followed by
coarse gravel with 25%.
Striking is the proportion of
fines with 16%. Small
boulders are rare.
179
70
60
63
50
40
14
11
Bo
ul
de
rs
S
ia
l
Ar
t if
ic
an
ks
<1
m
Un
de
rc
ut
B
ng
oo
ts
0
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Li
v
y
2
0
e
De
br
.<
eb
ris
D
Br
us
h/
W
oo
d
W
oo
dy
0
0,
3m
>0
.3
m
ac
ro
ph
yt
es
M
en
to
us
Fi
la
m
0
Tr
ee
s/
R
3
10
0
tr u
ct
ur
es
30
20
Al
ga
e
Cover Percentage
6.4
Generally, fish cover is very rare except for filamentous algae that are very frequent resulting
from slow flow, low water depth, and sporadically sparse vegetation cover.
60
46
50
40
38
30
23
23
Shrubs/Saplings
30
30
Herbs/Grasses/Forbs
40
20
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
Canopy >5m high
27%
45%
Deciduous
Deciduous
Mixed
Mixed
55%
73%
180
6.4
Canopy cover and understory vegetation are both mixed, not very dense, and represented by
a diversity of plants: big and small trees, shrubs, saplings, herbs, grasses, and tall forbs. The
ground layer is bare or vegetated primarily with grasses and forbs.
60
51
50
41
40
30
32
26
22
20
21
10
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
Canopy >5m high
36%
Deciduous
Deciduous
Mixed
64%
100%
Sporadically, the sparse canopy cover is dominated by big and small deciduous trees.
Understory is vegetated mostly with deciduous or coniferous shrubs and saplings. The
ground is covered with barren or bare dirt but also often overgrown with shrubs, saplings,
herbs, grasses, or forbs.
181
6.4
Mean Weighting
1.5
1.2
0.9
0.6
0.5
0.3
0.4
0.3
0
0
0.2
0
0.1
0
0
Bu
il d
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
w
ur
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
t iv
it y
0.1
Di
k
Pa
ve
m
e/
Re
ve
tm
en
t/R
ip
ra
p
0
On the left bank several human influences have been reported as buildings or trash, but
none is outstanding.
Mean Weighting
1.5
1.4
1.2
0.9
0.6
0.8
0.7
0.7
0.7
0.3
0.3
0
0
0
0
0
Bu
ild
in
gs
en
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/ O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
y
Lo
Fi
gg
el
in
d
g
O
pe
ra
t io
ns
M
in
in
g
Ac
t iv
it y
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
The right bank is heavily affected by trash and the main road. Further pressures affecting
mainly the surroundings are buildings and agricultural landuse like row crops and hay fields.
The most affecting human disturbance at this reach is the transverse structure at end.
182
6.4
6.4.3.3.1
Left bank
Figure 159 illustrates that the left bank is not heavily influenced by human disturbances.
The course of the river is affected but near-natural, dynamic processes are limited.
There are small scale alterations of the substrate composition and the hyporheic interstitial is
sporadically impacted. Figure 155 indicates that there is a high percentage of fines .
The connection between water and land is partly restricted, lateral dynamic processes are
limited, and natural structures are occasionally absent. Fish cover is mainly represented by
filamentous algae and overhanging vegetation (see Figure 156).
The characteristics of the bank and the riparian zone are slightly modified, vegetation cover
is insignificantly disturbed, and there are single non-native plants.
The vegetation of the surroundings is significantly disturbed because of spruce monocultures.
Right Bank
The course of the river is influenced but near-natural, flow characteristics slightly differ from
the natural status, and dynamic processes are limited.
There are small scale alterations of the substrate composition and the hyporheic interstitial is
sporadically impacted. Figure 155 indicates that there is a high percentage of fines .
The connection between water and land is partly restricted, lateral dynamic processes are
limited, and natural structures are occasionally absent. Fish cover is mainly represented by
filamentous algae and overhanging vegetation (see Figure 156).
The characteristics of the bank and the riparian zone are slightly modified. Vegetation cover
is significantly disturbed because the buffer zone is often heavily reduced and there are
single non-native plants.
The vegetation of the surroundings is heavily affected because of human influences such as
settlements, roads, and agricultural landuse which is also illustrated by Figure 160.
183
6.4
6.4.3.4 Reach 4/4
At the surveyed site, the Kreisbach flows
through a V-shaped valley in a wide open
valley with sides flaring out, a special case in
the Flysch Zone. In such valleys the pressure
of human activities is often high because of
the favorable conditions for agricultural
landuse (cf. Preis and Schager 2000).
The reach is characterized by a slow flow,
filamentous algae and large depositions
mainly consisting of cobbles. On the right side
the adjacent area is covered by a forest.
Reach 4/4
27%
Glide
Lateral Scour Pool
Trench Pool
51%
Riffle
The most frequent habitats
are riffles. The proportion of
glides is also high with 27%.
Pools
with
22%
are
pools and trench pools.
16%
6%
Reach 4/4
1%
11%
1%1% 2%
Boulders (large)
Boulders (small)
11%
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
10%
63%
Fines
Other
The
substrate
class
composition
is
totally
different from the other
reaches.
Cobbles
are
dominant with 63%. Fine and
coarse gravel is common
with a total of 21%. There is
also a noticeable proportion
of fines with 11%.
184
6.4
Cover Percentage
90
74
75
60
45
30
15
0
9
8
3
0
9
5
0
St
ru
ct
ur
es
ou
ld
er
s
Ar
t if
ic
ia
l
B
an
ks
<1
m
U
nd
er
cu
tB
ng
oo
ts
Ve
ge
t
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
e
Li
v
y
D
eb
ris
D
eb
r.
<
0,
3m
>0
.3
m
ac
ro
ph
yt
es
Br
us
h/
W
oo
d
Fi
W
oo
dy
la
m
M
en
to
us
Al
ga
e
0
Fish cover is diverse but rare. Only filamentous algae cover large areas of the river bottom.
60
50
45
44
40
34
27
30
18
20
10
4
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
Canopy >5m high
9%
9%
27%
36%
Coniferous
Coniferous
37%
Deciduous
Deciduous
Mixed
Mixed
82%
185
6.4
Canopy cover is dominated by small trees, understory by shrubs and saplings. The
vegetation types of both layers are mixed - coniferous and deciduous. The ground is
primarily covered with barren and bare dirt or overgrown with herbs, grasses, and forbs.
50
40
35
39
28
30
20
15
7
10
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Canopy >5m high
9%
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
41
37
9%
9%
Coniferous
Deciduous
Deciduous
Mixed
None
73%
100%
At some transects canopy cover is absent. Where present it is often dense consisting of
deciduous and coniferous trees. The understory is deciduous with a high proportion of
shrubs and saplings. Even though barren, bare dirt, or duff are common, large areas of the
ground are covered with mixed vegetation.
186
6.4
1.5
Mean Weighting
1.2
0.9
cti
vi
ty
0
A
tio
O
pe
ra
/H
ay
C
ro
ge
M
Pa
s
tu
Lo
re
/R
an
0
ns
0
Fi
el
d
ps
aw
n
Ro
w
La
nd
f
k/
L
t/O
( In
le
as
h
le
t)
ut
ai
lro
a
s
Pa
v
Pi
pe
R
oa
d/
R
re
d
Lo
d
t
s
in
g
/C
le
a
em
en
t
Bu
ild
t/R
ip
ra
p
m
en
R
ev
et
D
ik
e/
0
0.1
gg
in
g
0
0
Pa
r
0.4
0.3
0.6
0.5
ill
/T
r
0.3
0.7
in
in
g
0.6
The left bank is affected by trash and a lawn, followed by a cleared lot, buildings, and riprap.
1.5
0.9
1
0.7
ns
in
in
g
tio
0
M
el
d
O
pe
ra
ay
gg
in
g
/H
ge
re
/R
an
tu
Fi
C
ro
ps
aw
n
k/
L
Ro
w
nd
f
La
Pa
r
ill
/T
r
as
h
le
t)
ut
d
0
Pi
pe
s
( In
le
t/O
ai
lro
a
d/
R
Ro
a
re
d
Lo
t
s
en
t
/C
le
a
in
g
Bu
ild
em
Pa
v
m
en
R
ev
et
Di
ke
/
0.5
0.3
0
0.1
t/R
ip
ra
p
0
0.5
0.4
0.3
Ac
ti v
ity
0.6
Lo
0.6
Pa
s
Mean Weighting
1.2
The right bank and the adjacent area are affected by a multitude of human disturbances like
trash, roads, settlements, and agricultural areas.
187
6.4
6.4.3.4.1
Left bank
The course of the river is influenced but near-natural, flow characteristics slightly differ from
the natural status, and dynamic processes are limited.
There are small scale alterations of the substrate composition. Figure 163 indicates that
there is a high percentage of fines .
processes are limited. Fish cover is mainly represented by filamentous algae (see Figure
164).
The characteristics of the bank and the riparian zone are heavily modified. Vegetation cover
is significantly disturbed because the buffer zone is heavily affected by a garden (see Table
40 and Figure 167). That is also one reason why the vegetation of the surroundings is
significantly disturbed. Another cause are spruce mono-cultures.
Right Bank
The flow characteristics slightly differ from the natural status.
There are small scale alterations of the substrate composition. Figure 163 indicates that
there is a high percentage of fines .
The connection between water and land is undisturbed. Fish cover is represented mainly by
filamentous algae, boulders, riparian vegetation, and undercut banks (see Figure 164). The
characteristics of the bank and the riparian zone are slightly influenced, vegetation cover is
insignificantly disturbed, and there are single non-native plants (see Table 40).
The vegetation of the surroundings is heavily affected because of human influences such as
settlements, roads, and agricultural landuse which is also illustrated by Figure 168.
188
7
Discussion
7 Discussion
The aim of this thesis is the comparison and analysis of hydromorphological assessment
methods with the help of field surveys and the evaluated results as well as the examination
of the European Framework Directive. The discussion includes the analysis of
correspondences and differences between the outcomes of the NÖMORPH method and the
Physical Habitat Characterization.
7.1 Analysis of Correspondences and Differences between the
NÖMORPH method and the Physical Habitat Characterization
The comparison of the NÖMORPH method and the Physical Habitat Characterization shows
that there are considerable differences between the methods concerning field work and data
evaluation (see 4.3 Comparison NÖMORPH - Physical Habitat Characterization).
The Physical Habitat Characterization provides detailed results on river characteristics. The
measurements and estimations require a trained field crew of at least two people who need
several hours for the inventory of one river stretch. As the survey of whole water bodies or
catchment areas would be extremely time-consuming and cost-intensive, selected stretches
are representative of the population of flowing waters in a region. Evaluations of the status of
sample reaches occur in connection with biological indicators.
The NÖMORPH method is a qualitative hydromorphological assessment consisting of a
descriptive and an evaluating part. In one day, an experienced surveyor can map several
river kilometers which allows a rapid and comparatively cheap inventory of running waters.
During the field work, no detailed measurements are carried out so that the information
gathered from estimations gives a descriptive overview of surveyed stretches. The evaluation
of the hydromophological condition is performed with the help of single parameters and
summarizing parameters using condition classes.
Even though the NÖMORPH method and the Physical Habitat Characterization differ in
many aspects, the comparison of the evaluated data (see also chapter 6 Reference
Conditions and Results: sections Summarizing Presentation of Conclusions and Results)
illustrate a correspondence between the results of the two methods. The calculations of the
Physical Habitat Characterization do not result in hydromorphological condition
classifications, but they provide more detailed information on the sample reaches than the
descriptive part of the NÖMORPH method (see also APPENDIX B. Assessed Parameters of
the NÖMORPH method and the Physical Habitat Characterization). Furthermore, results of
the methods support and complement one another in many cases.
The following assessment results for the sampled reaches Retzbach 1/1 and Kreisbach 4/4
are used to highlight in which aspects the NÖMORPH method and the Physical Habitat
Characterization correspond and in which they differ strongly.
The condition classes of the summarizing parameters were identified via the evaluation of
single attributes (see also Table 23 and Appendix B). With the help of these attributes
detailed characterizations of the summarizing parameters can be carried out and compared
with the results of the Physical Habitat Characterization.
189
7
Discussion
Retzbach: Reach 1/1, right bank
A gravel road has led to heavy disturbances along the right bank and the adjacent area
which resulted in slightly to heavily modified conditions of the summarizing parameters (see
Table 41). As also illustrated by Figure 39 - the mean weighting of the road’s influence is
significantly high. Due to logging transportation and regular maintenance measures the
development of near-natural conditions is highly restricted.
Concerning channel geometry and flowability dynamic processes are limited and the river
course is restricted because of riprap. Figure 39 demonstrates that riprap is heavily affecting
the river channel.
Isolated impacts along the riverbed caused by concrete (substructure of a bridge) led to the
evaluation of the riverbed with condition class 2. Furthermore, substrate composition is
slightly altered caused by the input of fine gravel originating from the road that also
influences the hyporheic interstitial. This is also indicated by Figure 34.
The connectivity of water and land is characterized by the significant limitation of lateral
dynamic processes and the sporadical lack of natural structures as illustrated by Figure 39
and by Figure 34.
The typical characteristics of the bank and the riparian zone are heavily altered due to the
riprap and the gravel road. The vegetation cover is disturbed: Canopy cover is at some
transects nearly absent as well as understory that is even less evolved. The ground cover is
dominated by barren. Figure 37 clearly exemplifies these disturbances.
The vegetation of the surroundings is also modified as there is no vegetation buffer and
no understory. This is not indicated - neither by Figure 39 nor by Figure 37.
Table 41: Results of the evaluation of the 5 summarizing parameters - Reach 1/1, right
bank.
Summarizing Parameter
Channel Geometry and Flowability
Riverbed
Banks/Riparian Zone
Vegetation Surroundings
Condition Class
2-3
2
2-3
2-3
2-3
Overall Condition Class
2-3
1.5
Mean Weighting
1.4
1.2
1.1
0.9
0.6
0.3
0.2
0.3
0
0.3
0
0
0
0
0
Bu
ild
in
en
gs
t/C
le
ar
ed
Lo
Ro
t
ad
/R
ai
Pi
lro
pe
ad
s
( In
le
t/O
ut
le
t)
La
nd
fill
/T
ra
sh
Pa
rk
/L
aw
n
Pa
Ro
st
ur
w
e/
Cr
Ra
op
ng
s
e/
Ha
Lo
y
Fi
gg
el
in
d
g
O
pe
ra
tio
ns
M
in
in
g
Ac
t iv
it y
Pa
ve
m
Di
k
e/
Re
ve
tm
en
t/R
ip
ra
p
0
Figure 39: Reach 1/1 - Human disturbances and influences - right bank.
190
7
Discussion
70
60
50
57
40
30
29
16
16
16
6
5
Canopy >5m high
Canopy >5m high
9%
18%
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
20
10
18%
Deciduous
Deciduous
Mixed
Mixed
None
None
18%
64%
73%
Figure 37: Reach 1/1 - Riparian vegetation cover - right bank.
Reach 1/1
3% 1%
7%
4%
4%
Cascade
Glide
Lateral Scour Pool
Plunge Pool
Even though the reach consists
of different types of habitats, it is
dominated by riffle sections,
followed by pools in a variety of
shapes.
Trench Pool
Riffle
81%
Reach 1/1
3%
3%
5%
12%
Bedrock (rough)
2%
9%
Boulders (large)
Boulders (small)
27%
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
21%
18%
Fines
Concrete
The major substrate classes are
gravel and cobble. Sand and
fines play an insignificant role.
Even
if
the
substrate
composition may appear natural
at the first sight, the impact of
the adjacent road must not be
neglected. A culvert under the
gravel road is made out of
concrete.
191
7
Discussion
Kreisbach: Reach 4/4, left bank
The left bank is mainly affected by trash and a lawn, followed by a cleared lot, buildings, and
riprap as illustrated by Figure 167. The evaluation of the summarizing parameters resulted in
slightly modified and heavily modified conditions (see Table 42).
The course of the river is influenced but near-natural, flow characteristics slightly differ
from the natural status, and dynamic processes are occasionally limited. Figure 167
demonstrates that there are no heavy human influences on these parameters.
Riverbed: There are small scale alterations of the substrate composition. Figure 163
indicates that there is a high percentage of fines.
The connection between water and land is partially restricted and lateral dynamic
processes are limited due to single large boulders. Fish cover is diverse but rare. Only
filamentous algae cover large areas of the river bottom (see Figure 164). This is an indicator
that canopy cover is sparse or absent
The characteristics of the bank and the riparian zone are heavily modified. Vegetation
cover is significantly disturbed because the buffer zone is heavily affected by a garden - see
Figure 167. Figure 165 demonstrates that understory is rare but it is not apparent that large
areas of the ground are covered with lawn.
Furthermore, the results of the Physical Habitat Characterization do not indicate that the
vegetation of the surroundings is significantly disturbed by spruce mono-cultures.
Table 42: Results of the evaluation of the 5 summarizing parameters - Reach 4/4, left
bank.
Summarizing Parameter
Channel Geometry and Flowability
Riverbed
Banks/Riparian Zone
Vegetation Surroundings
Condition Class
2
1-2
1-2
2-3
3
Overall Condition Class
2
Cover Percentage
90
74
75
60
45
30
15
0
9
8
3
0
9
5
0
St
ru
ct
ur
es
ou
ld
er
s
Ar
t if
ic
ia
l
B
an
ks
<1
m
U
nd
er
cu
tB
ng
oo
ts
at
io
n
ov
er
ha
ng
i
Tr
ee
s/
R
e
y
Li
v
Ve
ge
t
D
eb
r.
<
0,
3m
>0
.3
m
D
eb
ris
Br
us
h/
W
oo
d
M
ac
ro
ph
yt
es
W
oo
dy
Fi
la
m
en
to
us
Al
ga
e
0
192
7
Discussion
60
50
45
44
40
34
27
30
18
20
10
4
Canopy >5m high
Herbs/Grasses/Forbs
Shrubs/Saplings
Herbs/Grasses/Forbs
Shrubs/Saplings
Small Trees <0.3m
0
Big Trees >0.3m
Percentage
10
Canopy >5m high
9%
9%
27%
36%
Coniferous
Coniferous
Deciduous
Deciduous
Mixed
Mixed
82%
37%
1.5
Mean Weighting
1.2
0.9
A
tio
ns
cti
vi
ty
0
in
in
g
Fi
el
d
O
pe
ra
gg
in
g
/H
ge
re
/R
an
0
Pa
s
tu
0
ay
C
ro
ps
aw
n
Ro
w
La
nd
f
k/
L
as
h
le
t)
ut
d
( In
le
Pi
pe
s
0
0.1
t/O
ai
lro
a
d/
R
R
oa
/C
le
a
re
d
Lo
t
s
in
g
Pa
v
em
en
t
Bu
ild
t/R
ip
ra
p
m
en
R
ev
et
D
ik
e/
0.6
Lo
0
0
Pa
r
0.4
0.3
ill
/T
r
0.3
0.7
0.5
M
0.6
193
7
Discussion
Reach 4/4
27%
Glide
Lateral Scour Pool
Trench Pool
51%
Riffle
The most frequent habitats
are riffles. The proportion of
glides is also high with 27%.
Pools
with
22%
are
pools and trench pools.
16%
6%
Reach 4/4
1%
11%
1%1% 2%
Boulders (large)
Boulders (small)
11%
Cobbles
Gravel (coarse)
Gravel (fine)
Sand
10%
63%
Fines
The
substrate
class
composition
is
totally
different from the other
reaches.
Cobbles
are
dominant with 63%. Fine and
coarse gravel is common
with a total of 21%. There is
also a noticeable proportion
of fines with 11%.
Other
The examples show that the results of the Physical Habitat Characterization support the
evaluation of the summarizing parameters in many ways. Nevertheless, there are cases
where the results of the methods are not corresponding. In addition, the outcomes of the
estimations and measurements of both methods can be incomprehensible and as a
consequence verbal descriptions are necessary:
One example is the left bank and the riparian zone of reach 4/4. The summarizing parameter
Banks/Riparian Zone includes, amongst other parameters, the estimation of the plant
species composition. The evaluation resulted in condition class 2-3 (see Table 42) because
of a lawn and the disturbed condition of the understory that is partially absent. In contrast, the
results for the riparian vegetation cover (see Figure 165) indicate that the understory is
sparse but not that the vegetation on the ground is disturbed due to non-native plant species.
As the main focus of both methods are the river channel and the riparian zone, the results for
these zones are stronger corresponding than the outcomes concerning the adjacent area
respectively the surroundings. The NÖMORPH method also evaluates the width of the buffer
zone, the structure of the vegetation of the surroundings, and its species composition. This is
demonstrated by the evaluation of reach 4/4 (left bank) as the species composition of the
adjacent area is significantly disturbed by spruce mono-cultures.
The Physical Habitat Characterization does not include estimations or measurements of the
vegetation structure or the plant species composition of the adjacent area. As human
influences are weighted using their distance to the wetted margin, the dimension of their
impact on the vegetation of the surroundings is not significantly apparent and has to be noted
in the comment section of the field survey forms.
194
7
Discussion
7.2 Conclusion
The environmental objectives of the European Water Framework Directive concerning
surface waters include the aim of achieving the good ecological status until 2015 (see
3.1.3.11 Commission Report). The goals of the assessments concerning the WFD were the
evaluation of the ecological status as well as of the “risk” of water bodies to fail the good
ecological status (see 3.1 The European Water Framework Directive).
The procedures as well as the features for the survey and assessment required to determine
the ecological status of running waters are described in the European Standard EN 14614
“Water quality – Guidance standard for assessing the hydromorphological features of rivers”
(see Table 19). Assessment categories and assessed features are assigned to three main
zones: channel, river banks / riparian zone, and floodplain.
For the investigation of the hydromorphological status quo of Austrian water bodies existing
data, amongst others, of the earlier NÖMORPH surveys were used. If necessary, additional
field surveys were carried out for which a “Screening method” was developed (see 3.2.3
Investigation of the Hydromorphological Status Quo of Austrian Water Bodies). The results of
the investigation are presented in the National River Basin Management Plan that was
published in 2009 (BMLFUW 2009).
A final review critically comments on the NÖMORPH method and the Physical Habitat
Characterization in the context of the Water Framework Directive:
Whereas the NÖMORPH method was developed for the assessment of the
ecomorphological condition class of running waters, the task of the Physical Habitat
Characterization as part of the Environmental Monitoring and Assessment Program (see
3.3.3 Environmental Monitoring and Assessment Program Western Pilot Study) is to describe
the ecological condition of streams with direct measures and the assessment of the relative
importance of potential stressors on aquatic vertebrates and benthic macroinvertebrates.
The NÖMORPH method and the Physical Habitat Characterization follow a similar scheme
as the CEN-standard 14614 concerning mapped and measured parameters (see Table 19
and Appendix B), but the methods differ considerably regarding field work procedures and
evaluation.
The calculations and the results of the Physical Habitat Characterization do not meet the
requirements of the WFD as they do not include an assessment of the hydromorphological
status using condition respectively evaluation classes. Nevertheless, the American method
provides further descriptive information to support the results of status evaluations.
Data of earlier NÖMORPH surveys were integrated into the investigation of the
hydromorphological status quo of Austrian water bodies. The evaluation process of the
NÖMORPH method is carried out using a 7-tier scale consisting of 4 main water body
condition classes and 3 intermediate water body condition classes. The condition
classification of the NÖMORPH was transformed to the ecological status classification and
the corresponding colour code of the Water Framework Directive using 5 classes (see Table
24). The expressive intermediate classes get lost during this process.
Both, the Physical Habitat Characterization and the NÖMORPH method do not bring into
focus the assessment of the floodplain to the extent as it is required by the European
Standard EN 14614 (e.g., wetland features, continuity of floodplain, see Table 19). Whereas
the NÖMORPH method provides an estimation of the vegetation conditions concerning
surroundings, an explicit evaluation of human impacts and pressures due to landuse is
missing. The estimations of the U.S. method involve different kinds of human influences on
the surroundings but do not include, amongst others, vegetation and wetland features.
Which survey method is used for the assessment of running waters depends on the purpose
respectively the goal of a project. A list of questions provides a framework to identify the
appropriate assessment method including issues such as: Require the tasks a qualitative or
a quantitative assessment or both? Should the assessment be descriptive or evaluative? Is
a large scale or a small scale assessment needed? What is the timeframe set? Which
195
7
Discussion
parameters are chosen to be surveyed and evaluated? How are reference conditions
established?
Roni et al. (2005) discussed “several logical steps that should be taken when designing any
monitoring and evaluation programme regardless of the type, number, and scale of aquatic
rehabilitation actions:
A well-designed monitoring and evaluation programme is a critical component of any
resource management, conservation, or rehabilitation activity. Determining the objectives of
a project and defining key questions and hypotheses are the critical first steps in developing
a monitoring programme. Defining the key questions will depend on the overall project
objectives. The evaluation of for example rehabilitation actions can be broken down into four
major questions based on scale (e.g., site, reach, watershed) and desired level of inference
(number of projects). These include evaluations of single or multiple reach-level projects and
single watershed or multiple watershed-level projects. For example, if one is interested in
whether an individual rehabilitation action affects local conditions or abundance (reach
scale), the key question would be: What is the effect of rehabilitation project x on local
physical and biological conditions? In contrast, if one is interested in whether a suite of
different project types has a cumulative effect at the watershed scale, then the key question
would be: What is the cumulative effect of all rehabilitation actions within the watershed on
physical habitat and populations of fish or other biota? While some actions such as riparian
plantings or instream wood placement can cover multiple adjacent reaches or occur in
patches throughout a geomorphically distinct reach, the initial question is still whether one is
interested in examining local (site or reach scale) or watershed-level effects on physical
habitat and biota.
From the key questions and specific hypotheses will flow the other important decisions
including appropriate monitoring design, duration and scale of monitoring, sampling
protocols, etc. The most difficult part and the biggest shortcoming of many rehabilitation
evaluation programmes is the study design. The lack of preproject data, adequate treatments
and controls, reference sites, and various management factors have limited the ability of
many studies to determine the effects of rehabilitation actions. There are many potential
study designs for monitoring single or multiple rehabilitation actions. None is ideal for all
situations and each has its own strengths and weaknesses. The key questions and
hypotheses will help determine the most appropriate design.
Determining which metrics and parameters to monitor and measure logically follows defining
goals and objectives, key questions and hypotheses, definition of scale, and selection of
study design. Selecting parameters also goes hand in hand with spatial and temporal
replication and sampling schemes. The appropriate parameters to monitor will differ by types
of rehabilitation as well as specific hypothesis.
Determining the spatial and temporal replication needed to detect changes following
rehabilitation can and should be established prior to monitoring. This will also help determine
whether the initial parameters selected will be useful in detecting change to the rehabilitation
action in questions.
Published literature is likely biased towards projects that showed an improvement following
rehabilitation. The lack of published evaluations of habitat rehabilitation emphasize the need
for better reporting and publishing both successful and unsuccessful projects. Rehabilitation
actions are experiments and reporting both positive and negative findings is crucial for
improving the understanding of the effectiveness of different measures, for spending limited
rehabilitation funds wisely, and ,above all, for restoring aquatic habitats and ecosystems”
(Roni et al. 2005).
196
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202
Appendix A.
APPENDIX
APPENDIX A.
Protected Areas
1. The register of protected areas has to include the following types of protected areas:
(i) areas designated for the abstraction of water intended for human consumption
(ii) areas designated for the protection of economically significant aquatic species;
(iii) bodies of water designated as recreational waters, including areas designated as bathing
waters
(iv) nutrient-sensitive areas, including areas designated as vulnerable zones
(v) areas designated for the protection of habitats or species where the maintenance or
improvement of the status of water is an important factor in their protection, including
relevant Natura 2000 sites.
2. The summary of the register required as part of the river basin management plan has to
include maps indicating the location of each protected area and a description of the
Community, national or local legislation under which they have been designated.
1
Appendix A.
Normative Definitions of Ecological Status Classifications
Definitions for High, Good and Moderate Ecological Status in Rivers
Table A-1: Biological quality elements.
Element
High status
Good status
Moderate status
Phytoplankton
The taxonomic composition of
phytoplankton
corresponds
totally or nearly totally to
undisturbed conditions.
There are slight changes
in the composition and
abundance of planktonic
taxa compared to the
type-specific
communities.
Such
changes do not indicate
any accelerated growth of
algae
resulting
in
undesirable disturbances
to
the
balance
of
organisms present in the
water body or to the
physico-chemical quality
of the water or sediment.
The composition of planktonic
taxa differs moderately from the
type-specific communities.
The average phytoplankton
abundance
is
wholly
consistent with the typespecific
physico-chemical
conditions and is not such as
to significantly alter the typespecific
transparency
conditions.
Planktonic blooms occur at a
frequency and intensity which
is consistent with the typespecific
physicochemical
conditions.
Macrophytes
and
phytobenthos
The taxonomic composition
corresponds totally or nearly
totally
to
undisturbed
conditions.
There are no detectable
changes in the average
macrophytic and the average
phytobenthic abundance.
Abundance
is
moderately
disturbed and may be such as to
produce a significant undesirable
disturbance in the values of other
biological and physico-chemical
quality elements.
A moderate increase in the
frequency and intensity of
planktonic blooms may occur.
Persistent blooms may occur
during summer months.
A slight increase in the
frequency and intensity of
the
type-specific
planktonic blooms may
occur.
abundance
of
macrophytic
and
phytobenthic
taxa
compared to the typespecific
communities.
Such changes do not
indicate any accelerated
growth of phytobenthos
or higher forms of plant
life
resulting
in
undesirable disturbances
to
the
balance
of
organisms present in the
water body or to the
physico-chemical quality
of the water or sediment.
The composition of macrophytic
and phytobenthic taxa differs
moderately from the type-specific
community and is significantly
more distorted than at good
status.
Moderate
changes
in
the
average macrophytic and the
average
phytobenthic
abundance are evident.
The phytobenthic community
may be interfered with and, in
some areas, displaced by
bacterial tufts and coats present
as a result of anthropogenic
activities.
The
phytobenthic
community
is
not
adversely affected by
bacterial tufts and coats
present
due
to
anthropogenic activity.
Benthic
invertebrate
fauna
The taxonomic composition
and abundance correspond
The ratio of disturbance
sensitive taxa to insensitive
taxa shows no signs of
abundance
of
invertebrate taxa from the
type-specific
communities.
The ratio of disturbance-
The composition and abundance
of invertebrate taxa differ
moderately from the type-specific
communities.
Major taxonomic groups of the
type-specific community are
absent.
2
Appendix A.
alteration
levels.
from
undisturbed
The level of diversity of
invertebrate taxa shows no
sign
of
alteration
from
undisturbed levels.
sensitive
taxa
to
insensitive taxa shows
slight alteration from typespecific levels.
The level of diversity of
invertebrate taxa shows
slight signs of alteration
from type-specific levels.
The ratio of disturbance-sensitive
taxa to insensitive taxa, and the
level
of
diversity,
are
substantially lower than the typespecific level and significantly
lower than for good status.
Element
High status
Good status
Moderate status
Fish fauna
Species composition and
abundance correspond totally
or nearly totally to undisturbed
conditions.
in species composition
and abundance from the
type-specific communities
attributable
to
anthropogenic impacts on
physicochemical
and
hydromorphological
quality elements.
The composition and abundance
of fish species differ moderately
from
the
type-specific
communities
attributable
to
anthropogenic
impacts
on
physico-chemical
or
hydromorphological
quality
elements.
All
the
type-specific
disturbance-sensitive species
are present.
The age structures of the fish
communities show little sign
of anthropogenic disturbance
and are not indicative of a
failure in the reproduction or
development of any particular
species.
The age structures of the
fish communities show
signs
of
disturbance
attributable
to
anthropogenic impacts on
physico-chemical
or
hydromorphological
quality elements, and, in
a few instances, are
indicative of a failure in
the
reproduction
or
development
of
a
particular species, to the
extent that some age
classes may be missing.
The age structure of the fish
communities shows major signs
of anthropogenic disturbance, to
the extent that a moderate
proportion of the type specific
species are absent or of very low
abundance.
Table A-2: Hydromorphological quality elements.
Element
High status
Good status
Moderate status
Hydrological
regime
The
quantity
and
dynamics of flow, and the
resultant connection to
groundwaters,
reflect
totally, or nearly totally,
Conditions consistent with the
achievement of the values
specified above for the
biological quality elements.
specified
above
for
the
River
continuity
The continuity of the river
is not disturbed by
anthropogenic activities
and allows undisturbed
migration
of
aquatic
organisms and sediment
transport.
specified
above
for
the
Morphological
conditions
Channel patterns, width
and depth variations, flow
velocities,
substrate
conditions and both the
structure and condition of
the
riparian
zones
specified
above
for
the
3
Appendix A.
correspond totally or
nearly
totally
to
Table A-3: Physico-chemical quality elements.
Element
High status
Good status
Moderate status
General
conditions
The values of the physicochemical elements correspond
Temperature,
oxygen
balance,
pH,
acid
neutralising capacity and
salinity do not reach levels
outside
the
range
established so as to
ensure the functioning of
the
type
specific
ecosystem
and
the
Conditions
consistent
with the achievement of
the
values
specified
above for the biological
quality elements.
Nutrient concentrations remain
within the range normally
associated with undisturbed
conditions.
Levels of salinity, pH, oxygen
balance,
acid
neutralising
capacity and temperature do not
show signs of anthropogenic
disturbance and remain within
the range normally associated
with undisturbed conditions.
Nutrient concentrations do
not exceed the levels
the ecosystem and the
Specific synthetic
pollutants
Concentrations close to zero
and at least below the limits of
detection of the most advanced
analytical techniques in general
use.
Concentrations
not
in
excess of the standards
set in accordance with the
procedure
detailed
in
section
1.2.6
without
prejudice
to
Directive
91/414/EC and Directive
98/8/EC. (<EQS)
Conditions
consistent
the
values
specified
quality elements.
Specific
synthetic
pollutants
Concentrations remain within
with undisturbed conditions
(background levels = bgl).
Concentrations
not
in
procedure
detailed
in
section 1.2.6 (2) without
prejudice
to
Directive
98/8/EC. (<EQS)
Conditions
consistent
the
values
specified
quality elements.
non-
4
Appendix A.
Definitions for Maximum, Good and Moderate Ecological Potential for Heavily
Modified or Artificial Waterbodies
Table A-4: Definitions for maximum, good and moderate ecological potential for
heavily modified or artificial waterbodies.
Element
Biological
elements
Maximum
potential
quality
Hydromorphological
elements
ecological
Good
potential
ecological
Moderate ecological
potential
The values of the relevant
biological quality elements
reflect, as far as possible,
those associated with the
closest comparable surface
water body type, given the
physical
conditions
which
result from the artificial or
heavily
modified
characteristics of the water
body.
in the values of the
relevant biological quality
elements as compared to
the values found at
maximum
ecological
potential.
There are moderate
changes in the values
of
the
relevant
biological
quality
elements as compared
to the values found at
maximum
ecological
potential.
The
hydromorphological
conditions are consistent with
the only impacts on the
surface water body being
those resulting from the
artificial or heavily modified
characteristics of the water
body once all mitigation
measures have been taken to
ensure the best approximation
to ecological continuum, in
particular with respect to
migration
of
fauna
and
appropriate spawning and
breeding grounds.
Conditions consistent with
the achievement of the
values specified above for
the
biological
quality
elements.
Conditions consistent
with the achievement
of the values specified
quality elements.
Physico-chemical
elements
correspond totally or nearly
totally to the undisturbed
conditions associated with the
surface water body type most
closely comparable to the
artificial or heavily modified
body concerned.
The values for physicochemical elements are
within
the
ranges
achievement
of
the
the
biological
quality
elements.
quality elements.
These
values
are
significantly
more
distorted than those
found
under
good
quality.
Physico-chemical
elements
General conditions
Nutrient concentrations remain
within the range normally
associated
with
such
The levels of temperature,
oxygen balance and pH are
consistent with the those found
in the most closely comparable
surface water body types
under undisturbed conditions.
Temperature and pH do
not reach levels outside
the ranges established so
as
to
ensure
the
functioning
of
the
ecosystem
and
the
achievement
of
the
the
biological
quality
elements.
5
Appendix A.
Nutrient
concentrations
do not exceed the levels
achievement
of
the
the
biological
quality
elements.
Element
Maximum
potential
Specific synthetic
pollutants
Specific non-synthetic
pollutants
ecological
Good
potential
ecological
Moderate ecological
potential
Concentrations close to zero
and at least below the limits of
detection
of
the
most
advanced
analytical
techniques in general use.
Concentrations not in
procedure detailed in
section 1.2.6 without
prejudice to Directive
98/8/EC. (<EQS)
quality elements.
Concentrations remain within
with the undisturbed conditions
found in the surface water
body type most closely
comparable to the artificial or
heavily
modified
body
concerned (background levels
= bgl).
Concentrations not in
procedure detailed in
section 1.2.6 (1) without
prejudice to Directive
98/8/EC. (< EQS)
quality elements.
6
Appendix A.
River Basin Management Plan
Amongst others, River Basin Management plans shall cover the following elements:
1. a general description of the characteristics of the river basin district including
for Surface Waters:
- mapping of the location and boundaries of water bodies;
- mapping of the ecoregions and surface water body types within the river basin;
- identification of reference conditions for the surface water body types;
for Groundwaters:
- mapping of the location and boundaries of groundwater bodies.
2. a summary of significant pressures and impact of human activity on the status of
surface water and groundwater, including:
-
estimation of point source pollution;
estimation of diffuse source pollution, including a summary of land use;
estimation of pressures on the quantitative status of water including abstractions;
analysis of other impacts of human activity on the status of water;
3. identification and mapping of protected areas as required;
4. a map of the monitoring networks and a presentation in map form of the results of the
monitoring programmes for the status of:
-
surface water (ecological and chemical)
groundwater (chemical and quantitative);
protected areas;
5. a list of the environmental objectives or surface waters, groundwaters and protected
areas
6. a summary of the economic analysis of water use
7.
- a summary of the programme or programmes of measures, including the ways in
which the established objectives are thereby to be achieved;
- a summary of the measures required to implement community legislation for the
protection of water;
- a report on the practical steps and measures taken to apply the principle of recovery
of the costs of water use;
- a summary of the controls on abstraction and impoundment of water, including
reference to the registers and identifications of the cases where exemptions have
been made;
- a summary of the measures taken to prevent or reduce the impact of accidental
pollution incidents;
- a summary of the measures taken for bodies of water which are unlikely to achieve
the objectives set out under Article 4;
- details of the supplementary measures identified as necessary in order to meet the
environmental objectives established;
7
Appendix A.
8. a register of any more detailed programmes and management plans for the river
basin district dealing with particular sub-basins, sectors, issues or water types,
together with a summary of their contents;
9. a summary of the public information and consultation measures taken, their results
and the changes to the plan made as a consequence;
The first update of the river basin management plan (at the latest 15 years after the date of
entry into force of the WFD and every six years thereafter) and all subsequent updates shall
also include:
-
-
a summary of any changes or updates since the publication of the previous version of
the river basin management plan;
an assessment of the progress made towards the achievement of the environmental
objectives, including presentation of the monitoring results for the period of the
previous plan in map form, and an explanation for any environmental objectives
which have not been reached;
a summary of, and an explanation for, any measures foreseen in the earlier version of
the river basin management plan which have not been undertaken;
a summary of any additional interim measures since the publication of the previous
version of the river basin management plan.
8
Appendix B.
Assessed Parameters
APPENDIX B.
B.1
Assessed Parameters of the NÖMORPH method
and the Physical Habitat Characterization
NÖMORPH
(translated from freiland Umweltconsulting 2001)
Left and right bank are surveyed individually.
Legend for Forms:
4 = predominant (76-100%)
3 = frequent (26-75%)
2 = minor (6-25%
1 = sparse (≤ 5%)
General Data
River Type
Valley Form ( gorge, v-shaped valley, u-shaped valley, v-shaped valley with narrow bottom,
valley with distinctive bottom, synclinal valley, plain valley)
Altitudinal Belt (planar 0-200m, collin 200-500m, submontane 500-700m, montane 7001500m, subalpine 1500-1900m, alpine 1900-2500m)
Morphological River Type (stretched, braiding, pendulous, sinuous, meandering)
Current Water Level (low, mean, moderately high)
Impact on flow conditions (absent, total water abstraction, residual water, abrupt wave,
impoundment, water inlet)
Overview - Characterization Surroundings
Rock, Wood, Forest, Wetland, Floodplain, Moor, Grassland extensive, Grassland intensive,
Agriculture/Cropland, Settlement Area, Circulation Area (frequency of parameters, see
legend for forms).
B.1.1 Channel Geometry and Flowability
Objective Description
Current (average current velocity m/s)
Flow behaviour (slow, uniform, swirled, turbulent)
Evaluation
Channel
Geometry - unaffected
(channel form)
- isolated interventions, semi-natural development of the course of
the river
- homogenization, definite shortening of the course of the river
- straightening, highly shortened course of the river
Flow Pattern
- equals the natural type
- minor changes to the natural type
- high changes to the natural type
- anthropogenic caused uniformity
Dynamic Component - unrestricted
- restricted
- barely possible
- not possible
9
Appendix B.
Assessed Parameters
B.1.2 Riverbed
Minimal Cross-Section Depth (m)
Maximal Cross-Section Depth (m)
Depth Variability (high, moderate, low, none)
Riverbed Stabilization (absent, present overlain with substrate, only stabilization structures,
structures probable)
Type Riverbed Stabilization (concrete, asphalt, pavement, pavement grouted, cobbles)
Natural Choriotopes
Natural Choriotopes are habitats of the river bed that are essential as creators of structures
because of substrate sizes/substrate sorting or as biotic elements and have been
sedimented respectively accumulated in a natural way (frequency or see legend for forms).
Table B-5: Natural Choriotopes - Abiotic
(ÖNORM 1997)
Size Class
Megalithal
Makrolithal
Size Range (mm)
>400
200 to 400
Mesolithal
63 to 200
Mikrolithal
20 to 63
Akal
Psammal
Pelal
2 to 20
0.063 to 2
<0.063
Description
Large boulders, bedrock
Coarse boulders, mainly head size, variable
fractions of stones, gravel and sand
Fist to hand sized stones with variable fractions of
gravel and sand
Coarse gravel (pigeon egg to a child’s fist size) with
fractions of medium to fine gravel and sand
Fine to medium gravel
Sand
Silt, loam, clay and mud
Table B-6: Natural Choriotopes - Biotic
(ÖNORM 1997)
Size Class
Xylal
Phytal
Detritus
Sapropel
Woody debris, roots, branches etc.
Underwater plants, floating stocks or polsters, bacteria (not
recorded with the NÖMORPH method), extensive fungi stocks
and fungi villi (often with detritus accumulations), polsters of
moss and algae
Accumulation of fine particulate organic material
Organic sludge
Evaluation
Substrate Characteristic
- typical, undisturbed
- small scale alterations
- definite homogenization
- uniform, non-local material
10
Appendix B.
Assessed Parameters
Riverbed Relief
- natural shape
- local alterations
- definite alterations
- anthropogenic caused uniformity
- unrestricted or naturally restricted
- small scale restricted
- existent just locally
- restricted or rudimentary
Hyporheic Interstitial
B.1.3 Connectivity Water - Land
Width-Variability (high, moderate, low, none)
Shoreline Stabilization (absent, isolated, area by area, continuous)
Type of Shoreline Stabilization (revetment, riprap, concrete, etc.)
Important Woody Debris Accumulation(s)
Important Bed Load Accumulation(s) (gravel banks, sand banks, silt banks)
Evaluation
Connectivity
Structures
- locally restricted, dynamic restricted
- definite disturbance, dynamic only local
- no dynamic, plain/heavily obstructed
- local absence of natural structures or secondary structures
- loss of natural structures because of lining
- no natural structures, plain wetted margin
B.1.4 Banks / Riparian Zone
Cross-sections of longitudinal course (variable, uniform; trapeze, doubletrapeze, arc, etc.)
Dike (absent, present)
Bank Gradient (vertical, steep >30 degrees, moderate 10-30 degrees, plain <10 degrees)
Bank Stabilization (absent, isolated, area by area, continuous)
Dimension of the bank stabilization ( bankfull height, 1/3 of the bank, 3/4 of the bank, up to
top edge of the bank)
Type Bank Stabilization (revetment, riprap, concrete, etc.)
Canopy Cover Woods (+/- 100%, >50%, <50%, absent)
Shadowing of the water body (complete, predominant, partly, absent)
Vegetation Types
The frequency of each of the following parameters is estimated (see legend for forms) for
banks/acclivities and surroundings:
Herbaceous Pioneer Vegetation, Cane Brake, Tall Forb Meadow, Nitrophilous Fringe,
Herbaceous Alien Plants, Woody Pioneer Plants, Woods of the Soft Wood Floodplain Forest,
Woods of the Hard Wood Floodplain Forest, Marsh Area, Moor, Pasture, Fallow Land,
11
Appendix B.
Assessed Parameters
Grassland Extensive, Grassland Intensive, Lawn, Field, Deciduous Forest, Mixed Forest,
Coniferous Forest, Woody Alien Plant Species, Sealing.
Evaluation
Bank/ Acclivity Characteristic
Species Composition of Vegetation
Riparian Vegetation Cover and Age
- natural bank, no disturbance
- marginally anthropogenic altered
- heavily anthropogenic altered
- heavily obstructed acclivity with no structure
- typical, unaffected
- typical, partly non-typical
- domination of non-typical species
- non-typical
- natural circumstances
- little restricted condtions/compositions
- definite restricted condtions/compositions
- anthropogenic degraded
B.1.5 Vegetation Surroundings
Total Width of Woody Riparian Vegetation Zone (>10m, several rows 5-15m, one row 2-5m,
one row interrupted, isolated woods/absent)
Canopy Cover Woods Surroundings (+/- 100%, >50%, <50%, absent)
Vegetation Types
The frequency of each of the following parameters is estimated (see legend for forms) for
banks/acclivities and surroundings:
Herbaceous Pioneer Vegetation, Cane Brake, Tall Forb Meadow, Nitrophilous Fringe,
Herbaceous Alien Plants, Woody Pioneer Plants, Woods of the Soft Wood Floodplain Forest,
Woods of the Hard Wood Floodplain Forest, Marsh Area, Moor, Pasture, Fallow Land,
Grassland Extensive, Grassland Intensive, Lawn, Field, Deciduous Forest, Mixed Forest,
Coniferous Forest, Woody Alien Plant Species, Sealing.
Evaluation
Buffer Zone Total
Species
Composition
Surroundings
Vegetation Cover
Surroundings
&
of
Age
Vegetation
of
Vegetation
- wide, structured
- reduced width and structure
- locally existent
- absent
- - typical, unaffected
- typical, partly non-typical
- domination of non-typical species
- non-typical
- - natural circumstances
- little restricted
- definite restricted
- anthropogenic degraded
12
Appendix B.
B.2
Assessed Parameters
(Peck et al. 2006)
B.2.1 Channel/Riparian Cross-Section
Substrate Cross-Sectional Information
At 5 vertical measure points: Left, LCtr, Center, RCtr, Right
Distance Left Bank (m)
Depth (cm)
Substrate Size Class (see Table B-8: Substrate Size Class Codes)
Embeddedness (%)
Bank Measurements
Bank angle (degrees, left bank, right bank)
Undercut Distance (m, left, right)
Wetted Width (m)
Bar Width (m)
Bankfull Width (m)
Bankfull Height (m)
Incised Height (m)
6 measurements with the Densiometer (center up, center down, center left, center right, left
bank, right bank).
Fish Cover / Other (in channel)
Cover estimation of (see Table B-7: Vegetation Types and Cover Classes):
Filamentous Algae, Macrophytes, Woody Debris >0.3m, Brush/Woody Debris <0,3m, Live
Trees/Roots, Overhanging Vegetation <1m, Undercut Banks, Boulders, Artificial Structures.
Riparian Vegetation Cover
(Left and right bank are estimated individually)
Canopy >5m high (vegetation type, big trees trunk >0.3m, small trees trunk <0.3m)
Understory 0.5 - 5m high (vegetation type, shrubs/saplings, herbs/grasses/forbs)
Ground Cover <0.5m high (shrubs/saplings, herbs/grasses/forbs, barren/bare dirt/duff)
Table B-7: Vegetation Types and Cover Classes
(Peck et al. 2006)
Vegetation Type
D = Deciduous
C = Coniferous
E = Broadleaf Evergreen
M = Mixed
N = None
Cover Classes
0 = Absent (0%)
1 = Sparse (<10%)
2 = Moderate (10-40%)
3 = Heavy (40-75%)
4 = Very heavy (>75%)
13
Appendix B.
Assessed Parameters
Human Influence Estimates
Left and right bank are estimated individually.
Proximity of:
Wall/Dike/Revetment/Riprap/Dam, Buildings, Pavement/Cleared Lot, Road/Railroad, Pipes
(Inlet/Outlet), Landfill/Trash, Park/lawn, Row Crops, Pasture/Range/Hay Field, Logging
Operations, Mining Activity.
Proximity Classes: 0 = not present, P = >10m, C = within 10m, B = on bank
B.2.2 Thalweg Profile
Thalweg Depth (cm)
Soft/Small Sediment (present, absent)
Channel Unit Code (see Table B-9: Channel Unit Habitat Classes
Pool Form Code (if pool present, see Table B-10: Pool Form Codes
Side Channel (present, absent)
Back Water (present, absent)
Bar Width (m, present, measurement station 0 and 5/7)
Wetted Width (m, measurement station 0 and 5/7)
Large Woody Debris
(Count of woody pieces all/part in Bankfull Channel and pieces that bridge above bankfull
channel: ≥ 10cm small end diameter; ≥ 1.5m length)
Diameter Large End (0.1 - < 0.3m, 0.3 - 0.6m, 0.6-0.8m, > 0.8m)
Length (1.5-5m, 5-15m, >15m, 1.5-5m, 5-15m, >15m)
B.2.3 Riparian "Legacy" Trees and Invasive Alien Plants
Largest potential Legacy Tree visible between Transects
(A to K, for K upstream 4 channel widths, wadeable streams: ca. 50 from left and right bank)
Diameter at Breast Height (m, 0-0.1, 0.1 - 0.3, 0.3- 0.75, 0.75 – 2, >2)
Height (m, <5, 5 – 15, 15 – 30, >30)
Distance from Wetted Margin (m)
Type (deciduous, coniferous, broadleaf, evergreen)
Alien Plant Species
(within riparian plots 10m x 10m, present/none)
Species
B.2.4 Slope and Bearing
Slope (%/cm)
Bearing (0° - 360°/400°)
Proportion (%/cm; main measurement,
supplemental measurement)
first
supplemental
measurement,
second
14
Appendix B.
Assessed Parameters
B.2.5 Stream Discharge
Velocity-Area Procedure
Distance from Bank (cm), Depth (cm), Velocity (m/s)
Timed Filling Procedure
5 Repeats, Volume (L), Filling Time (s)
Neutral Buoyant Object Procedure
3 Floats, Float Distance (m), Float Time (s)
1 - 3 Cross Sections (upper, middle, lower) on Float Reach:
Width (m), Depth at 5 Measure Point (cm)
Direct Determination of discharge
Current Velocity Meter (m³/s)
B.2.6 Channel Constraint
Channel Pattern (one channel, anastomosing, braided)
Channel Constraint (V-shaped valley; broad valley: constrained by incision; narrow valley:
not very constrained; broad valley: unconstrained)
Constraining Features (bedrock, hillslope, terrace, human bank alterations, no constraining
features)
Channel length in contact with constraining feature (%)
Average Bankfull Width (m)
Average Valley Width (m, visual estimated)
B.2.7 Torrent Evidence Assessment
Evidence of Torrent Scouring
Evidence of Torrent Deposits
No Evidence
Table B-8: Substrate Size Class Codes
(Peck et al. 2006)
Code
RS
Size Class
Bedrock (Smooth)
Size Range (mm)
>4000
RR
Bedrock (Rough)
>4000
HP
XB
SB
CB
GC
GF
SA
Hardpan
Boulders (large)
Boulders (small)
Cobbles
Gravel (Coarse)
Gravel (Fine)
Sand
>4000
>1000 to 4000
>250 to 1000
>64 to 250
>16 to 64
>2 to 16
>0.06 to 2
FN
Fines
≤0.06
WD
RC
Wood
Concrete
Regardless off size
Regardless off size
Description
Smooth surface rock bigger than a
car
Rough surface rock bigger than a
car
Firm, consolidated fine substrate
Yard/meter stick to car size
Basketball to yard/meter stick size
Tennis ball to basketball size
Marble to tennis ball size
Ladybug to marble size
Smaller than ladybug size, but
visible as particles - gritty between
fingers
Silt Clay Muck (not gritty between
fingers)
Wood and other organic particles
Record size class in comment field
15
Appendix B.
OT
Assessed Parameters
Other
Regardless off size
Metal, tires, car bodies
(describe in comments)
etc.
Table B-9: Channel Unit Habitat Classes
(Peck et al. 2006)
Class (Code)
Plunge Pool (PP)
Trench Pool (PT)
Lateral Scour Pool (PL)
Backwater Pool (PB)
Impoundment Pool (PD)
Pool (P)
Glide (GL)
Riffle (RI)
Rapid (RA)
Cascade (CA)
Falls (FA)
Dry Channel (DR)
Description
Pool at base of plunging cascade or falls
Pool-like trench in the center of the stream
Pool scoured along a bank
Pool seperated from main flow off the side of the channel (large
enough to offer refuge to small fishes). Includes sloughs
(backwater with marsh characteristics such as vegetation), and
alcoves ( a deeper area off a wide and shallow main channel)
Pool formed by impoundment above dam or constriction
Pool (unspecified type)
Water moving slowly, with a smooth, unbroken surface. Low
turbulence.
Water moving, with small ripples, waves and eddies - waves
not breaking, surface tension not broken. Sound: babbling,
gurgling.
Water movement rapid and turbulent, surface with intermittent
white-water with breaking waves. Sound: continuous rushing,
but not as loud as cascade.
Water movement rapid and very turbulent over steep channel
bottom. Much of the water surface is broken in short, irregular
plunges, mostly whitewater. Sound: roaring.
Free falling water over a vertical or near vertical drop into
plunge, water turbulent and white over high falls. Sound: from
splash to roar.
No water in the channel, or flow is submerged under the
substrate (hyporheic flow)
Categories of Pool-forming Elements
Pools: Still water, low velocity, a smooth, glassy surface, usually deep compared to other
parts of the channel.
Table B-10: Pool Form Codes
(Peck et al. 2006)
Code
N
W
R
B
F
WR, RW, RBW
OT
Category
Not applicable, Habitat Unit is not a Pool
Large Woody Debris
Rootwad
Boulder or Bedrock
Unknown Cause (unseen fluvial processes)
Combinations
Other (description in the comments section)
16
Appendix C.
Forms NÖMORPH and Western Pilot Study
APPENDIX C.
Figure C-1: NÖMORPH; Main Form Part 1: General Data, Overview – Characterization
Surroundings, Channel Geometry and Flowability, Riverbed (see also B.1 NÖMORPH, B.1.1
Channel Geometry and Flowability, and B.1.2 Riverbed).
17
Appendix C.
Figure C-2: NÖMORPH; Main Form Part 2: Connectivity Water-Land, Banks/Riparian
Zone, Vegetation Surroundings, Overall Evaluation (see also B.1.3 Connectivity Water Land, B.1.4 Banks / Riparian Zone, and B.1.5 Vegetation Surroundings).
18
Appendix C.
Figure C-3: NÖMORPH; Additional Form 1: Structures interrupting the River Continuum
(river name, serial number, ID structure, kind of structure, fish ladder, width, height,
comments).
19
Appendix C.
Figure C-4: NÖMORPH; Additional Form 2: Backwaters (e.g., oxbows - waterbody name,
serial number, ID backwater, connection, flow conditions).
20
Appendix C.
Figure C-5: EMAP – Western Pilot Study; Channel-Riparian Cross-Section Form:
Substrate Cross-Sectional Information, Bank Measurements, Canopy Cover Measurements,
Fish Cover, Riparian Vegetation Cover, Human Influence Estimates.
21
Appendix C.
Figure C-6: EMAP – Western Pilot Study; Thalweg Profile and Woody Debris Form:
Thalweg Profile, Large Woody Debris.
22
Appendix C.
Figure C-7: EMAP – Western Pilot Study; Riparian "Legacy" Trees and Invasive Alien
Plants Form 1: Largest potential Legacy Tree visible, Alien Plant Species.
23
Appendix C.
Figure C-8: EMAP – Western Pilot Study; Riparian "Legacy" Trees and Invasive Alien
Plants Form 2: Largest Potential Legacy Tree visible, Alien Plant Species.
24
Appendix C.
Figure C-9: EMAP – Western Pilot Study; Slope and Bearing Form: Slope, Bearing,
Proportion (main measurement, first supplemental measurement, second supplemental
measurement).
25
Appendix C.
Figure C-10: EMAP – Western Pilot Study; Stream Discharge Form: Velocity-Area
Procedure, Neutrally Buoyant Object Procedure, Timed Filling Procedure, Direct
Determination of Discharge.
26
Appendix C.
Figure C-11: EMAP – Western Pilot Study; Channel Constraint and Field Chemistry:
Channel Pattern, Channel Constraint, Constraining Features, Contact with Constraining
Feature, Bankfull Width, Valley Width.
27
Appendix C.
Figure C-12: EMAP – Western Pilot Study; Torrent Evidence Assessment Form:
Evidence of Torrent Scouring, Evidence of Torrent Deposits.
28
Appendix D.
Field Work Equipment
APPENDIX D.
Field Work Equipment
FORMS
NÖMORPH:
•
•
Form 1: General data, Overview – characterization surroundings, Layout of the line
and flowability, Riverbed
Form 2: Connectivity water-land, Banks/Riparian zone, Vegetation surroundings,
Overall evaluation
Physical Habitat Characterization:
-
Stream Discharge Form
Thalweg Profile and Woody Debris Form
Slope and Bearing Form
Channel/Riparian Cross-section Form for a main channel transect
Riparian “Legacy” Tree and Invasive Alien Plants Form
Channel Constraint and Field Chemistry Form
EQUIPMENT
-
Clinometer, 180°, Suunto Finland
-
Compass, Suunto Helsinki, Code: KB-14/400 (400°)
-
TruPulse 360°B Laser
-
GPS Receiver ETREX/Garmin
-
Digital camera
-
Meter stick, 140cm, with cm markings
-
Leveling rod, 4m
-
Barrier tape for flags
-
Pencil, sharpener
-
Black marker
-
Batteries
-
Waders
-
Rubber boots
29

Comparison and Analysis of Austrian and American

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