what is hydromorphology

Transcription

what is hydromorphology
Assessing and predicting the effects
of hydromorphological alteration
and restoration
Francesco Comiti
Free University of Bozen-Bolzano (Italy)
Credits to : Tom Buijse, Angela Gurnell, Massimo Rinaldi,
Daniel Hering, Erik Mosselmann
OUTLINE OF THE PRESENTATION
• What is hydromorphology ?
• Overview of the REFORM project
• REFORM Hydromorphological framework
• Hydromorphological classification methods
• Tools for prediction hydromorphological response
• Few conclusions (?)
2
WHAT IS HYDROMORPHOLOGY ?
Longitudinal
1. Spatial
continuity
Lateral
Channel pattern
2. Morphology
Cross-section
Substrate
3. Vegetation
4. Flow regime
3
THE RELEVANCE OF HYMO CHARACTERISTICS
Unimpaired («natural»)
hydromorphological conditions
Max (high) ecological status
(provided water quality is ok)
Not necessarily correlated to
diversity/abundance of biota !
4
Hydromorphological
pressures
highly relevant in Europe
(Source: European Environmental Agency)
5
To carry out sound restoration actions on a river, we first need
to know/assess:
- The «natural» hydromorphological characteristics of
that river (without pressures, past/present/future)
- The effects of the HYMO pressures on the
ecosystem (biota)
- What will be the benefits of the restoration and their
sustainability in the future
- Assess if the benefits are bigger than the costs !!
6
REFORM PROJECT
• COLLABORATIVE PROJECT
LARGE SCALE INTEGRATING PROJECT
• ENV.2011.2.1.2-1
HYDROMORPHOLOGY AND ECOLOGICAL OBJECTIVES OF WFD
• GRANT NO. 282656
• DURATION: 2011-2015
7
REFORM Partners
25 partners from 14
European countries
No.
Participant organisation name
Short
name
Country
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Stichting Deltares (Coordinator)
Stichting Dienst Landbouwkundig Onderzoek B.V. – Alterra
Aarhus University – National Environmental Research Institute
Universitaet fuer Bodenkultur Wien
French Research Institute for agricultural and environmental engineering
Danube Delta National Institute for Research & Development
Swiss Federal Institute of Aquatic Science and Technology
Ecologic Institut gGmbH
Leibniz-Institute of Freshwater Ecology and Inland Fisheries
European Commission Joint Research Centre
Masaryk University
Natural Environment Research Council – Centre for Ecology & Hydrology
Queen Mary, University of London
Swedish University of Agricultural Sciences
Finnish Environment Institute
University of Duisburg-Essen
University of Hull
Università di Firenze
Universidad Politécnica de Madrid
VU University Amsterdam, Institute of Environmental Studies
Warsaw University of Life Sciences
Centro de Estudios y Experimentacion de Obras Publicas
Dutch Government Service for Land and Water Management
Environment Agency of England and Wales
Istituto Superiore per la Protezione e la Ricerca Ambientale
Deltares
Alterra
AU-NERI
BOKU
Cemagref
DDNI
Eawag
Ecologic
IGB
JRC
MU
NERC-CEH
QMUL
SLU
SYKE
UDE
UHULL
UNIFI
UPM
VU-IVM
WULS
CEDEX
DLG
EA
ISPRA
Netherlands
Netherlands
Denmark
Austria
France
Romania
Switzerland
Germany
Germany
Italy
Czech Republic
UK
UK
Sweden
Finland
Germany
UK
Italy
Spain
Netherlands
Poland
Spain
Netherlands
UK
Italy
8
Objectives of REFORM
APPLICATION
1. Select indicators for cost-effective monitoring
2. Improve tools and guidelines for restoration
RESEARCH
1. Review existing information on river degradation and restoration
2. Develop a process-based hydromorphological framework
3. Understand how multiple stress constrains restoration
4. Assess the importance of scaling on the effectiveness of
restoration
5. Develop instruments for risk and benefit analysis to support
successful restoration
DISSEMINATION
1. Enlarge appreciation for the benefits of restoration
9
Interaction with end-users
Communication & Dissemination Strategy
End-user groups: policy makers, practitioners, scientists
Standard
–
Website, Newsletters (2/yr), Policy Briefs (3)
Advanced
–
–
–
WIKI linking theory to practice and experience
Interactive preparation of end-user workshop
Interaction with ECOSTAT
Events
–
–
–
–
Interactive stakeholder workshop (Feb 2013)
Local workshops in case study catchments (tbd)
Summer school (2015)
Final conference (2015)
Target groups
• General Public
Target groups
• Universities
• River Basin Planners
• NGOs
• Environmental Agencies
• Policy Makers
Tools
Tools
• Policy Briefs
• Website
• Stakeholder Workshop
• Newsletter
• Wiki River Restoration
• Scientific Papers
10
Cooperation with …
make use of earlier research projects
(e.g. REBECCA, WISER,
FORECASTER)
RESTORE (LIFE+ Information &
Communication)
European Centre for River Restoration
(ECRR)
WFD Implementation: ECOSTAT
common implementation strategy
(CIS)
Gary Brierley, Johan Kling, Margaret Palmer,
Hervé Piégay, Peter Pollard,
Advisory Board of REFORM
Ursula Schmedtje, Bas van der Wal
11
Natural
processes
Restoration &
Mitigation
Degradation
Understand how disturbed sediment
dynamics and multiple stress
constrain restoration
WP 4
WP 3
WP 2
Effects of
hydromorphological
changes on rivers
and floodplain
ecosystems
Hydromorphological
and ecological
processes and
interactions
Develop a process-based and
ecologically relevant
hydromorphological framework
* Translate science to practice
* Select indicators for costeffective monitoring
* Improve tools and
guidelines for restoration
WP 6 Applications and
Effects of river
restoration
Assess theWP
importance
of scaling and
5
catchment conditions on the
Restoration
effectiveness of restoration
potential and
strategy
stakeholders
stakeholders participation
participation
Review existing information on
river degradation and restoration
WP 7 Knowledge
Knowledge dissemination
dissemination and
and
WP 1 Meta-analysis
Develop instruments for benchmarking,
targets, risk and benefit analysis to
tools support successful restoration
Enlarge appreciation for the
benefits of restoration
WP 8 Consortium coordination and management
12
Deliverables
REFORM stakeholder
workshop
Brussels 26-27 Feb 2013
13
REFORM GEO-WIKI
Open source web-based knowledge management system
Know-How
Knowledge
Evaluation
River typology
Measures
Case studies of
river restoration
projects
Pressures
Hydromorphology
Tools (assessment,
indicators, models,
guidelines, monitoring)
Biota
Ecosystem goods
and services
European environmental
directives and policies
©REFORM
14
REFORM GEO-WIKI – TOOLS
River Characterisation
Pressures
Measures
Tools
Case studies
Biological Quality
HYMO Quality
Ecosystem Services
EU Directives
Database
15
HYDROMORPHOLOGICAL FRAMEWORK (WP2)
The hydromorphology of a naturally-functioning river reach is
driven by:
i.Regional characteristics: particularly climate
ii.Catchment characteristics: translate properties of the
regional climate into flows of water and sediment,
iii.Valley setting: dictates topographic slope and lateral
confinement of river reaches,
iv.Reach properties that moderate response to flows of water
and sediment: e.g. bed-bank-floodplain sediment calibre and
structure, aquatic and riparian vegetation.
HYDROMORPHOLOGICAL FRAMEWORK
THERE ARE COMPLEX MULTI-SCALE CONTROLS ON RIVER-FLOODPLAINS
SPATIAL SCALES IN HYDROMORPHOLOGY
River basin
Channel reach
Channel unit
Channel element
(from Rinaldi et al 2013)
19
CURRENT HYDROMORPHOLOGICAL CLASSIFICATIONS
i.
ii.
iii.
iv.
v.
Rarely record information beyond the channel and
immediate margins
Give a snapshot of river characteristics that focuses on
forms rather than processes
Take limited account of the cascade of larger-scale
factors and processes that influence hydromorphology
and ecology.
Rarely take account of time lags between changes at one
site / spatial scale and adjustments at another site / scale.
Often provide descriptions or counts of features, but little
interpretation of them as indicators of reach functioning
now, in the past or in the future.
“REFORM” HYDROMORPHOLOGICAL FRAMEWORK
i. Adopts a multi-scale approach
ii. Is open-ended to maximise use of existing
information
iii. Guides users on information required, how it can be
collected – estimated - analysed to explain river
character and behaviour.
iv. Provides a basis for predicting how a reach might
react to changes (e.g. removal of engineering
modifications, reinstatement of sediment supply)
and...
v. Allows definition of site-specific, “reference” conditions
against which present condition can be
assessed.
Region
HYDROMORPHOLOGICAL
SCALES
Catchment
Landscape unit
PREVIOUS EXAMPLES:
Habitat Classification: Frissell et al.(1986)
Segment
Reach
River Scaling Concept: Habersack et al. (2000)
Eco-geomorphic Characterization: González del
Tánago and García de Jalón (2004)
River Styles Framework: Brierley & Fryirs (2005)
Geomorphic unit
Hydraulic unit
River element
Stream Evaluation and Hydromorphological
Classification (Morphological Quality Index):
Rinaldi et al. (2013)
Region
Catchment
Landscape unit
CONTROLS ON RIVER
BEHAVIOUR
(confinement; gradient;
delivery of WATER,
SEDIMENT, PLANT
PROPAGULES, WOOD to
river reaches)
Segment
REACH
RIVER AND FLOODPLAIN
TYPE, DYNAMICS,
SENSITIVITY
Geomorphic unit
Hydraulic unit
River element
DYNAMIC SUITE OF
RIVER AND FLOODPLAIN
FEATURES
(PHYSICAL HABITATS)
UPSTREAM AND LATERAL
CONTROLS:
SEDIMENT AVAILABILITY,
SEDIMENT SIZE,
FLOW REGIME,
SEDIMENT TRANSPORT
REGIME
VEGETATION.
DIFFERENT TYPES OF
REACH PROVIDE:
(i) DIFFERENT LANDFORM
(HABITAT) ASSEMBLAGES
(ii) DIFFERENT LANDFORM
(HABITAT) STABILITY
sediment size
fine sand
sand
gravel
Church, 2006
boulders
sediment supply
BRAIDED
ANASTOMOSED
decreasing channel stability
cobbles
bed material dominated
WANDERING
MEANDERING
suspended sediment material dominated
decreasing channel stability
channel gradient
STEP-POOL, CASCADE
silt
DIFFERENT TYPES OF
REACH PROVIDE:
(i) DIFFERENT LANDFORM
(HABITAT) ASSEMBLAGES
(ii) DIFFERENT LANDFORM
(HABITAT) STABILITY
(iii) DIFFERENT PIONEER
LANDFORMS CREATED BY
PLANTS AND WOOD
Gurnell et al., 2012
Pioneer vegetated landforms / habitats in
different reach types:
• indicate hydro morphological dynamics
• influence threshold behaviour
DIFFERENT TYPES OF
REACH PROVIDE:
(i) DIFFERENT LANDFORM
(HABITAT) ASSEMBLAGES
(ii) DIFFERENT LANDFORM
(HABITAT) STABILITY
(iii) DIFFERENT PIONEER
LANDFORMS CREATED BY
PLANTS AND WOOD
(iv) DIFFERENT
FLOODPLAIN LANDFORM
(HABITAT) ASSEMBLAGES
Nanson & Croke, 1992
CURRENT STATE
Region
Catchment
Landscape unit
Segment
REACH
Geomorphic unit
Hydraulic unit
River element
Stage 1: DELINEATION
Draft methods to define spatial
units
Stage 2: CHARACTERISATION
Draft recommendations on data
sources and methods for
characterising units
Stage 3: INDICATORS
Preliminary set of indicators at
each scale.
Preliminary approaches to linking
scales (downscaling) and to
inferring processes from forms
(upscaling)
Conceptual model of
ecohydromorphological
interactions (in progress)
Stage 4: FROM PAST TO FUTURE
(in progress)
River Frome, UK: DELINEATION
Catchment –Landscape Unit –Segment
Catchment delineation
-5m NextMAP DTM
Landscape unit delineation
-3 units based on bedrock (supported by
elevation and Land cover)
Segment delineation
-7 based on catchment area (+ >0.5km2)
LU 1
S1
L U2
S2
S1
S2
L U3
S3
S1
S2
S3
Rivers Magra – Vara, Italy:
DELINEATION Segment – Reach Delineation
segments
reaches
M. Rinaldi, B. Belletti
Dipartimento di Ingegneria Civile e Ambientale
Università di Firenze
REACHES IN THE MAGRA-VARA BASIN
Reach
Length
(m)
Confine
ment
degree
(%)
Confine
ment
index
Confinement
Morphology
Si
Bi
Ai
Slope
(%)
Width
(m)
Dominant
sediment calibre
n.a.
n.a.
n.a.
10.31
8
n.a.
M1.1
3685
>90
n.a.
Confined
Magra river
Single thread
M2.1
4780
>90
n.a.
Confined
Single thread
n.a.
n.a.
n.a.
5.65
8
Cobble
M2.2
2977
70
4
Partly Confined
Sinuous
1.11
1
1
2.45
12
Cobble
M2.3
M2.4
M2.5
1390
957
2603
52
43
47
3
7
4
Partly Confined
Partly Confined
Partly Confined
Sinuous
Sinuous
Sinuous
1.02
1.08
1.07
1
1
1
1
1
1
1.80
1.78
1.42
13
18
18
Cobble
Cobble
Cobble
M3.1
1012
20
4
Partly Confined
Straight
1.03
1
1
1.58
32
Cobble
M3.2
3188
47
3
Partly Confined
Sinuous
1.1
1.2
1
0.88
69
Cobble
M3.3
1259
0
5
Unconfined
Sinuous
1.07
1.2
1
1.11
97
Gravel/Cobble
M3.4
2628
<10
5
Unconfined
Braided
1.03
1.6
1.1
0.88
180
Cobble/Gravel
M3.5
4211
<10
4
Unconfined
Braided
1.04
2.15
1.6
0.85
190
Cobble/Gravel
M3.6
4518
33
2.5
Partly Confined
Sinuous
1.06
1.16
1
0.54
82
Cobble/Gravel
M3.7
1776
20
3.3
Partly Confined
Wandering
1.31
1.14
1
0.48
163
Cobble/Gravel
M3.8
4038
<10
5.7
Unconfined
Wandering
1.05
1.33
1
0.52
99
Cobble/Gravel
M3.9
1890
32
2.9
Partly Confined
Wandering
1.008
1.33
1
0.37
121
Gravel
M4.1
6925
39
3.2
Partly Confined
Sinuous
1.05
1
1
0.29
63
Gravel
M5.1
4750
<10
5.8
Unconfined
Wandering
1.07
1.6
1.2
0.29
127
Gravel
M6.1
4881
<10
13.2
Unconfined
Wandering
1.003
1.5
1.08
0.10
189
Gravel
M6.2
4546
<10
15.6
Unconfined
Sinuous
1.11
1.3
1
0.11
151
n.a.
M6.3
5985
<10
18.7
Unconfined
Sinuous
1.11
1
1
0.10
211
n.a.
HYDROMORPHOLOGICAL ASSESSMENT METHODS (D1.1)
Hydromorphological assessment methods
– Existing published reviews (Raven et al., 2002; Weiss et al., 2008;
Fernandez et al., 2011)
• 1. Physical habitat assessment
– Methods to identify, survey and assess physical habitats
• 2. Riparian habitat assessment
– Previous type but more specific for riparian habitats and vegetation
• 3. Morphological assessment
– Methods performing a more general evaluation of ‘morphological
conditions’ (pressure-response)
• 4. Hydrological regime alteration assessment
– Methods specific for the assessment of the hydrological regime
• 5. Longitudinal fish continuity assessment
– Methods specific for continuity of fish communities
Summary of reviewed methods for each category
Total: 139
Methods implemented by EU countries for the WFD (total 21)
Type of
assessment
Country
Name of the method
Key references
Austria
Hymo status assess guidelines
Mühlmann, 2010
Czech Republic
HEM - Hydroecological Monitoring method
Langhammer, 2007
Morphological
Denmark
DHQI - Danish Habitat Quality Index
Pedersen & Baattrup-Pedersen, 2003
Physical habitat
England & Wales
RHS - River Habitat Survey
Raven et al., 1997 (and follows)
Physical habitat
France
CarHyCe – Hydrological characterization of rivers
ONEMA, 2010
Physical habitat
France
SYRAH-CE & AURAH-CE – Hydromorphology auditing
Chandesris et al., 2008; Valette et al., 2010
Morphological
ONEMA, 2010
Longitudinal continuity
France
ROE – National database on barriers to flow continuity
ICE - Information on ecological continuity
Germany
LAWA-FS - Stream habitat survey - field survey method
LAWA, 2000
Physical habitat
Germany
LAWA-OS - Stream habitat survey - overview survey method
LAWA, 2002
Physical habitat
Ireland
RHAT - River Hydromorphology Assessment Technique
Murphy & Toland, 2012
Physical habitat
Italy
CARAVAGGIO - Core assessment of river habitat value and
hydromorphological conditions
Buffagni et al., 2005
Physical habitat
Italy
MQI - Morphological Quality Index
Rinaldi et al., 2011
Morphological
Latvia
Methodology for the assessment of Hydromorphological
changes
PPT from Sigita Šulca, 2012
Morphological
The Netherlands
Handboek HYMO - Manual for hydromorphology
Dam et al., 2007
Physical habitat
Poland
MHR - River Hydromorphological Monitoring
Ilnicki et al., 2009
Physical habitat
Portugal
Adaptation of RHS
Ferreira et al., 2011
Physical habitat
Scotland
MImAS - Morphological Impact Assessment System
UKTAG, 2008
Morphological
Slovakia
Hydromorphological Assessment Protocol for the Slovak
Republic
NERI & SHMI, 2004; Lehotský & Grešková,
2007
Physical habitat
Slovenia
Indices for assessment of hymo alteration of rivers
Tavzes & Urbanic, 2009
Physical habitat
Spain
IHF - Index for the assessment of fluvial habitat in Med. rivers Pardo et al., 2002
Physical habitat
Spain
QBR - Riparian Forest Quality Index
Riparian habitat
Munné & Prat, 1998
Physical and riparian habitat assessment
(RHS, LAWA, CARAVAGGIO, CarHyCe, RHAT, DHQI, IHF, QBR, RQI, etc.)
• Strengths
– Provide accurate inventory useful to characterize the range
of physical and riparian habitats and link them to biological
conditions
Limitations
Detailed site-specific data collection: application to large
number of water bodies impracticable
– Limited consideration on processes
– Inherent tendency to define high status/reference
conditions on the basis of the presence and abundance of
features
– Gaps in the terminology used to describe morphological
units in physical habitat surveys
–
Morphological assessment
(MImAS, MQI, SYRAH, etc.)
• Strengths
– Use of a more robust geomorphological approach, with
consideration of physical processes at appropriate spatial
and temporal scales
– Such an approach supports the development of a better
understanding of cause-effect relationships
Limitations
– Physical processes generally difficult to assess, and
application by public agencies needs specialists
– Limited attention to morphological units
Hydrological regime alteration assessment
(IAHRIS, IARI, QM-HIDRI, etc.)
• Strengths
– Use of robust indicators based on quantitative, statistical or
physically-based models
Limitations
– Requires large data sets and long- time series, which are
often not available
– Hydrological alterations at short time scales, such as
hydropeaking, is normally not assessed
– Groundwater alterations are generally not included
Fish continuity assessment
(ROE-ICE, RDB-DRN, etc.)
• Strengths
– Most of these methods are based on a basic inventory of
existing barriers: they provide a straightforward
information relatively simple to obtain
Limitations
– Provide some basic information, but while relatively few of
them carry out any deeper assessment
– Few standardized protocols/structured methods exist
Methods implemented for WFD
–
–
Consideration of physical processes remains the main gap
Integrated use of different components of the assessment
is limited but is recently increasing
Relevance for WFD
1. Need for a more comprehensive
hydromorphological assessment
– Consideration of physical processes should be enhanced in
hydromorphological assessment methods
Core of hydromorphological assessment
– A. Morphological assessment
– B. Hydrological assessment
Integrated characterization
– C. Physical habitats (in-channel and riparian) (selected sites)
– D. Fish continuity
2. Need for initial screening tools
– First characterization and selection of potential critical reaches at
catchment scale, based on remote sensing and available
information on existing pressures
HYDROMORPHOLOGICAL CLASSIFICATION
Hydromorphological condition of a reach depends on dynamic
interactions between water, sediment and plants. Therefore:
1. Needs to be placed in a catchment context (to capture impact of
catchment process cascade and human interventions)
2. Needs to be evaluated over time (to capture sensitivity, dynamics
and trajectories of change)
The outputs of WP2 will benefit users of WFD implementation by:
1.
2.
3.
4.
Providing a flexible assessment framework
Providing indicators of hydromorphological condition that can be
derived from commonly measured or freely available data sets
Improving understanding of linkages between hydrology, channel
and floodplain morphodynamics, and ecology.
Informing sustainable approaches to ecohydromorphological
management and restoration of river reaches
REFERENCE CONDITIONS FOR ASSESSING HYMO ALTERATIONS ?
• Problematic ! Referring to a “pristine” or “historical” and “static”
condition is neither feasible nor worthwhile
• Long hystory of human-induced river adjustments
• But rivers change pattern and size even without human pressure
(climatic variations, tectonic) !
REFERENCE CONDITIONS FOR ASSESSING HYMO ALTERATIONS ?
Static reference state concept should be replaced by a ’guiding
image’ of an ‘ecologically dynamic state’ (e.g. Palmer et al.,
2005) corresponding to ‘dynamic equilibrium’ in terms of
physical processes (at the short term scale !).
We must emphasize the uncertainty in our
morphological predictions rather than to hide it !!
?
42
TOOLS FOR HYMO VARIATIONS
1. Conceptual models (still quite
relevant) !!
2. Evolutionary trajectories
(Lane, 1955)
(Surian et
al 2009)
3. Empirical/statistical (useful only
if applied to similar conditions)
4. Numerical models to refine the
assessment (but only if properly
used, e.g. running different
scenarios for initial/boundary
conditions)
43
WHICH DIRECTIONS TO GO IN THE RESTORATION ?
(from Rinaldi, 2013)
44
TAKE HOME MESSAGES (CONCLUSIONS ?)
• Rivers are dynamic in nature, and we have to bear
that in mind when planning restoration actions
• At present our knowledge of river dynamics and of
cause-effects relations is very weak
• The prediction of HYMO variations related to
pressures/restoration is subject to huge uncertainty
• Several tools together must be used for such
predictions, different scenarios always tested
45