WATER-MAP Project

Transcription

WATER-MAP Project

INTERREG III B project
Development and utilization of vulnerability maps for the monitoring and
management of groundwater resources in the Archimed area (WATER-MAP)
WATER-MAP Project
REPORT ON THE HYDROMETEOROLOGIC AND
GEOLOGICAL DATA (DELIVERABLE 3.2)
WATER-MAP Project
WATER-MAP Project
REPORT ON THE HYDROMETEOROLOGIC AND
GEOLOGICAL DATA (DELIVERABLE 3.2) 1
INDEX
1
Introduction ........................................................................................................................ 4
1.1
References .................................................................................................................. 7
2
Hydrometeorological and Hydrogeological data of Sarigkhiol basin, Kozani prefecture,
Western Macedonia region, Greece ........................................................................................... 8
2.1
Location-Description of the basin .............................................................................. 8
2.2
Meteorological data.................................................................................................. 10
2.3
Geological framework.............................................................................................. 15
2.4
Hydrogeological characterisation............................................................................. 17
2.4.1
Alluvial aquifer ................................................................................................ 17
2.4.2
Groundwater balance- Piezometric surface...................................................... 18
2.4.3
Hydraulic parameters ....................................................................................... 19
2.5
Groundwater Quality................................................................................................ 21
2.6
References ................................................................................................................ 21
3
Hydrometeorological and Hydrogeological data of Florina basin, Florina prefecture,
Western Macedonia region, Greece ......................................................................................... 22
3.1
Location-Description of the basin ............................................................................ 22
3.2
3.3
3.4
Hydrogeological characterisation............................................................................. 25
3.5
Data Collection......................................................................................................... 25
3.6
References ................................................................................................................ 26
4
Hydrometeorological and Hydrogeological data of Monopoli area (Apulia, south-eastern
Italy) ......................................................................................................................................... 27
4.1
Location-Description of the area.............................................................................. 27
4.2
Meteorological features............................................................................................ 29
4.3
Geological setting..................................................................................................... 35
4.4
Collection of data: database and preliminary statistical processing......................... 39
4.5
Hydrogeological features ......................................................................................... 41
4.6
References ................................................................................................................ 48
5
Hydrometeorological and Hydrogeological data of Piana del Fucino, Abruzzo region,
Italy 49
5.1
General description .................................................................................................. 49
5.2
Acquired data for Fucino plain................................................................................. 50
1
Report coordinated by CNR–IRPI, by Polemio M. (Scientific person on charge) with the main technical
contribution of Dragone V., email: [email protected].
2
Report on the hydrometeorologic and geological data (deliverable 3.2)
5.3
Meteorological aspects............................................................................................. 51
5.3.1
Rainfall ............................................................................................................. 51
5.3.2
Temperature ..................................................................................................... 54
5.3.3
Potential evaporation – transpiration (PET)..................................................... 56
5.4
Geological and Hydrogeological aspects ................................................................. 57
5.4.1
Geology ............................................................................................................ 57
5.4.2
Hydrogeology................................................................................................... 58
5.5
Piezometric surface .................................................................................................. 59
6
Hydrometeorological and Hydrogeological data of the Mean Sea Level aquifer recharge
area in the island of Malta ........................................................................................................ 61
6.1
Location-Description of the study-area.................................................................... 61
6.2
Meteorological Data................................................................................................. 62
6.2.1
6.2.1 Rainfall .................................................................................................... 63
6.2.2
Temperature ..................................................................................................... 64
6.2.3
Evapotranspiration ........................................................................................... 64
6.2.4
Runoff............................................................................................................... 65
6.2.5
Infiltration......................................................................................................... 66
6.3
Geological Framework ............................................................................................. 66
6.3.1
Geological description of the region ................................................................ 67
6.3.2
Stratigraphical Sequence .................................................................................. 68
6.4
Hydrogeological Characterisation............................................................................ 70
6.4.1
Conceptual model of the groundwater body .................................................... 70
6.4.2
Hydrogeological features ................................................................................. 71
6.4.3
Groundwater Balance....................................................................................... 72
6.5
6.6
6.6 References .......................................................................................................... 76
7
Hydrometeorological and Hydrogeological data of Mouriki basin, Kozani prefecture,
Western Macedonia region, Greece ......................................................................................... 78
7.1
Location-Description of the basin ............................................................................ 78
7.2
7.2.1
Rainfall and Temperature................................................................................. 81
7.2.2
Evaportranspiration .......................................................................................... 83
7.2.3
Runoff............................................................................................................... 86
7.3
7.4
Hydrogeology........................................................................................................... 88
7.4.1
Hydrogeological characterisation..................................................................... 88
7.4.2
Piezometric surface .......................................................................................... 90
7.4.3
Hydraulic parameters ....................................................................................... 91
7.5
7.6
Soil Quality .............................................................................................................. 92
7.7
References ................................................................................................................ 94
3
WATER-MAP Project
1 Introduction
In recent years, there has been an increase in demand for pure water in many countries.
Groundwater, as a source of public water supply, presents significant advantages compared to
surface water, due to its protection from surface pollutants.
Human activities that were developed in last decades without comprehensive planning
support, in any case not considering the aquifer vulnerability, may severely increase the risk
of groundwater pollution. The location of any settlement that is a potential source of pollution
has to be planned on the basis of detailed hydrogeological data and analysis, reported in a
clear and straightforward form for use by decision-makers. This kind of maps quantitatively
represents the sensitivity of any aquifer to receiving and transporting pollutants that may
worsen groundwater quality (Civita, 1994).
The intrinsic vulnerability map of aquifers is an effective information tool for these planning
activities. The results provide important information and the vulnerability maps could be used
by local authorities and decision makers. These maps are designed to indicate the areas of
greatest potential for groundwater contamination on the basis of hydrogeological conditions
and human impacts.
WATER-MAP (www.watermap.eu) pursues the utilization of aquifer vulnerability
assessment maps to support the spatial development planning process.
WATER-MAP has the following specific objectives, some of these are:
to establish a network of the ARCHIMED areas that face similar risks of groundwater
pollution;
to exchange information on the existing level of knowledge on the state of groundwater
resources and their vulnerability in the participating regions, as well as on existing policies
and legislation;
to apply the DRASTIC and SINTACS methods in order to produce detailed maps for
assessing groundwater vulnerability;
to incorporate the produced results in a spatial monitoring system for the identification of
environmental risks;
to assess alternative land-use and spatial development practices in relation to groundwater
pollution risks;
4
to develop a decision support system that will use all information and offer water
management guidance;
to identify similarities and differences in the regional contexts and showcase examples of best
practice;
to jointly develop a best practice handbook reacting to the different interests and expectations
of the actors involved;
to train staff of the participating regions in implementing best practices;
to disseminate all information and consult with the public through the organization of special
events and through the establishment of a public dialogue mechanism;
to present the network’s results to regional policy makers;
to incorporate groundwater management considerations in regional and spatial development
policies.
The concept of the groundwater vulnerability is based on the assumption that the physical
environment may provide some degree of protection to groundwater against human activities.
WATER-MAP uses GIS-based vulnerability maps related to groundwater pollution in the
Archimed areas as a prime tool to assist regional development planning.
The most efficient measure to fight against groundwater pollution is the integral prevention.
For this purpose vulnerability maps are used, as a tool to determine areas where aquifers are
in high risk of pollution. In general, vulnerability refers to the sensitivity of an aquifer system
to pollution due to an external action. The concept of vulnerability is based on the assumption
that the physical environment may provide some degree of protection to groundwater against
potential contaminants.
WATER-MAP focuses on the Archimed areas where groundwater is in heavy stress, because
of agricultural, industrial, tourism, or other activities.
The vulnerability map of the aquifer is an indispensable tool for the effective management of
groundwater resources and to support environmental planning. Several approaches have been
proposed by different authors to evaluate intrinsic vulnerability. Most of the methods for
detailed vulnerability mapping are based on the integrated analysis of several variables using
different algorithms.
One the most widely used models to assess groundwater vulnerability is the DRASTIC model
within a GIS environment. The acronym DRASTIC corresponds to the initial of the included
parameters: Depth, Recharge, Aquifer media, Soil media, Topography, Impact of the vadose
zone media, and hydraulic Conductivity of the aquifer. The method developed by the United
5
WATER-MAP Project
State Environmental Protection Agency (EPA) as a technique for assessing groundwater
pollution potential (Aller et al., 1987).
Determination of the DRASTIC index involves multiplying each parameter weight by its site
rating and summing the total. The equation for the DRASTIC (DI) index is:
DI=DrDw+RrRw+ArAw+SrSw+TrTw+IrIw+CrCw
Where: D, R, A, S, T, I, C are parameters (
Table 1), r rating for the study area
being evaluated and w the importance weight for the parameter. Each parameter has a rating
scale between 1 and 10.
PARAMETER
SYMBOL
D
Depth
R
Recharge
A
Aquifer media
S
Soil media
T
Topography
I
Impact of the vadose zone media
V
Hydraulic Conductivity of the aquifer
Table 1 – DRASTIC parameters.
The DRASTIC method will be tested using data from hydrochemical analyses of groundwater
samples. The results will provide important information and the vulnerability maps will be
used from local authorities and decision makers.
The thematic maps and the final map of the DRASTIC groundwater vulnerability will be
developed in a Geographical Information System (GIS). The SINTACS method (Civita,
1994), including seven parameters will be applied in order to compare the results. The
SINTACS method divides the study area into a grid with regularly spaced cells and assigns
scores to selected variables for each cell. The variables used in this method are as follows:
S or depth to water, I or actual infiltration or net recharge, N or unsaturated zone, T or soil
media, A or aquifer media, C or hydraulic conductivity and S or terrain slope.
Both DRASTIC and SINTACS methods belong to rating methods for assessing groundwater
vulnerability.
This Report describes the data collection and the climatic, meteorological, geological and
hydrogeological characteristics, including parameters useful for aquifer vulnerability
assessment, of each study area selected for the WATER-MAP project.
6
1.1 References
Aller, L., Bennet, T., Lehr, JH., Petty, RJ., Hackett, G. (1987): DRASTIC: a standardized
system for evaluating groundwater pollution potential using hydrogeological setting.
EPA/600/2-87/035. US Env. Protection Agency, 163 p.
Al-Zabet, T. (2002): Evaluation of aquifer vulnerability to contamination potential using the
DRASTIC method. Environmental Geology (2002) 43:203-208.
Civita, M. (1994): Le carte della vulnerabilità degli acquiferi all’ inquinamento. Teoria &
practica. (Aquifer vulnerability maps to pollution). Pitarora Ed., Bologna (in Italian).
7
WATER-MAP Project
2 Hydrometeorological and Hydrogeological data of Sarigkhiol
basin, Kozani prefecture, Western Macedonia region, Greece2
N. T. Kazakis, K. S. Voudouris
Lab. of Engineering Geology & Hydrogeology, Dept. of Geology, Aristotle University of Thessaloniki,
54124 Thessaloniki, Greece. Email: [email protected]
2.1 Location-Description of the basin
Sarigkhiol basin (Figure 1) is located in the north-eastern part of Kozani Prefecture
(Municipalities Ellispontos and Dimitrios Ipsilantis), Western Macedonia region, Greece,
covering an area of 423 km2 or 407 km2 except of lignite pit.
Lowlands (elevation <1000 m asl) and mountainous areas occupy 219 and 204 km2,
respectively of the total area (Figure 2 and Figure 3). The mean altitude of the basin is about
952 m asl and the mean slope 1.5% (Table 2). The alluvial aquifer covers an area about of 60
km2 with a mean altitude of 665 m asl.
2
Chapter realised by Aristotle University of Thessaloniki, Lab. of Engineering Geology & Hydrogeology, Dept.
of Geology, 54124 Thessaloniki, Greece. Author K. S. Voudouris, email: [email protected]
8
Figure 1: Topographic map of the study area.
Figure 2: Shaded map of the Sarigkiol basin.
Figure 3: Topographic map of the Sarigkiol basin.
9
WATER-MAP Project
At the west side there is Askio Mountain, at the east side there is Vermio Mountain, at the
south side there is Skopos Mountain. The north border is nowadays the open pit of the south
field lignite mines and partly the tectonic horst of Komanos.
Soulou Torrent, which intersects the basin, was artificially opened up in 1954.
The land is used mainly for cultivation of cereals and cows and sheep graze the area. In a
large part of the area irrigated agriculture is practised. Lignite deposits occurring in the basin
and are one of the most rich energy resources in the Balkans. A large amount of 65% of
country’s total electric power is produced in this area.
Area (km2)
Mean altitude (m asl)
Maximum altitude (m asl)
Mean slope (%)
407.0*
952.0
1256.0
1.5
*Except of lignite pit
Table 2: General characteristics of the Sarigkhiol basin.
2.2 Meteorological data
The area is characterized by a semi-arid, Mediterranean climate, with an annual temperature of
12.96 °C and an annual rainfall of 643 mm. About 70-80% of annual rainfall occurs in wet
period, while summers are usually dry.
Based on results of previous studies, a decrease of annual rainfall for movement Eastward was
identified.
Rainfall height is correlated strongly with the altitude. Using the last square method (data from
10 rain gauges of the wider area) the relationship between the mean annual rainfall (P) and the
elevation (H) was explained by the regression straight line:
P (mm) =0.28 H (m) + 373
(600 m < H <1000 m
Thus, the mean annual rainfall increases by 28 mm per 100 m of ground elevation.
The annual rainfall variability of two representative rain gauges gauges is shown in Figure 4
and Figure 5. In Table 3, Table 4, Table 5 and Table 6, are listed the meteorological data of
the Sarigkhiol basin.
Based on Thornthwaite-Mather method, the estimated mean actual evapotranspiration at
Pontokomi gauge is 417 mm, 74% of the annual rainfalls (Table 7).
Figure 6 shows the water balance (mm) at Pontokomi gauge for the period 1988-1998, based
on rainfall (P), potential (Ep′) and actual (Er) evapotranspiration. Water deficit is the amount
of water by which the Ep’ and P differ in any month if Ep’>P. From the graph it is found that
10
water deficit is recorded during the period May-October, while water surplus and natural
recharge is recorded during the period January-April when the water storage in the soil has its
maximum capacity. During the period May-July the process of consumption of water storage
in the soil takes place, while the period November-December is the replenishment period of
water storage in the soil.
Altitude
Rain gauge
(m asl)
Longitude
Annual rainfall
Standard
Min-Max
(mm)
deviation
rainfall
Latitude
values (mm)
1 Voskochori
770
210 45”
400 58”
532.5
116.1
297-776
2 Pontokomi
718
210 46”
400 25”
606.5
88.3
385-774
Table 3: Rainfall data during the hydrological years 1980-81 and 2000-01 (mm).
1
2
J
54.4
38.2
F
49.4
38.8
M
53.8
34.4
A
50.6
46.9
M
55.7
60.9
J
39.0
38.2
J
30.1
35.5
A
32.8
36.8
S
23.3
24.0
O
53.4
47.0
N
88.3
70.3
D
75.7
61.6
*1: Pontokomi gauge, 2: Voskochori gauge.
Table 4: Mean monthly rainfall (mm) for period 1980-81/2000-01.
gauge
J
F
M
A
M
J
J
A
S
O
N
D
annual
Kozani
2.2
2.7
3.7
10.3
18.6
22.0
24.3
23.9
17.2
13.1
5.1
6.0
12.4
Table 5: Mean monthly temperature (oC) at Kozani gauge for period 1988-1998.
Mean annual rainfall (mm)
Mean annual temperature (oC)
Mean annual actual evapotranspiration (mm)
Mean annual discharge (x106 m3/y)
643.0
12.4
417.0
10-15
Table 6: Summary statistics of meteorological data in alluvial aquifer of Sarigkhiol basin.
11
2000-01
1999-00
1998-99
1997-98
1996-97
1995-96
1994-95
1993-94
1992-93
2000-01
1999-00
1998-99
1997-98
1996-97
1995-96
1994-95
1993-94
1992-93
1991-92
1990-91
1989-90
1988-89
1987-88
1986-87
1985-86
1984-85
1983-84
1982-83
1981-82
1980-81
annual rainfall (mm)
300
1991-92
1990-91
1989-90
1988-89
1987-88
1986-87
1985-86
1984-85
1983-84
1982-83
1981-82
1980-81
annual rainfall (mm)
WATER-MAP Project
Voskochori station (770 m)
900
800
700
600
500
400
...
200
100
0
Figure 4: Annual rainfall (mm) at Voskochori rain gauge.
Pontokomi station (680 m)
1000
900
800
700
600
500
400
300
200
100
0
Figure 5: Annual rainfall (mm) at Pontokomi gauge.
12
180
160
140
mm
120
P
100
Ep
80
Er
60
40
20
0
J
F
M
A
M
J
J
A
S
O
N
D
months
Figure 6: Water balance at Pontokomi gauge. P=rainfall, Ep′=potential and Er=actual evapotranspiration.
According to measured data, an average volume of about 10-15 106 m3/y of water discharges
out of the Sarigkhiol basin by Soulou torrent.
The infiltration ratio determined in other areas with same lithology and soil texture, is
estimated to be as 10-22% of the annual rainfall, assuming that the soil in the study area is of
medium texture with moderately to well-drained soil. Changes in the amount of rainfall
infiltration caused by changes in land use. An average percentage of 20.6% was used in the
alluvial aquifer of the Sarigkhiol basin.
13
WATER-MAP Project
Τhornthwaite-Mather method
J
F
T (0C)
M
A
Ws =
M
90 mm
J
α=
J
1,370
A
Coefficient of actual evapotranspiration
74,0%
S
O
N
D
Mean/Total
2.20
0.29
2.70
0.39
3.70
0.63
10.30
2.99
18.60
7.31
22.00
9.42
24.30
10.95
23.90
10.68
17.20
6.49
13.10
4.30
5.10
1.03
6.00
1.32
4.5
0.84
5.9
0.83
9.1
1.03
37.0
1.11
83.2
1.24
104.7
1.25
120.0
1.27
117.3
1.18
74.8
1.04
51.5
0.96
14.1
0.83
17.7
0.81
P (mm)
3.8
31.6
4.9
36.3
9.4
39.9
41.1
56.8
103.2
60.0
130.9
33.9
152.4
39.1
138.4
39.0
77.7
23.83
49.4
47.1
11.7
83.3
14.3
72.9
Deficit
0.0
0.0
0.0
0.0
43.2
97.0
113.3
99.4
53.9
2.3
0.0
0.0
Surplus
27.8
31.4
30.5
15.7
0.0
0.0
0.0
0.0
0.0
0.0
71.6
58.7
APWL
0.0
0.0
0.0
0.0
-43.2
-140.2
-253.5
-352.9
-406.9
-409.2
0.0
0.0
Ws (mm)
90.0
90.0
90.0
90.0
55.7
19.0
5.4
1.8
1.0
1.0
72.5
90.0
ΔWs
0.0
0.0
0.0
0.0
-34.3
-36.7
-13.6
-3.6
-0.8
0.0
71.6
17.5
Er (mm)
3.8
4.9
9.4
41.1
94.3
70.6
52.7
42.6
24.6
47.1
11.7
14.3
417.2
Q (mm)
27.8
31.4
30.5
15.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
41.2
146.6
i
Ep (mm)
N
Ep” (mm)
12.43
55.81
737.33
563.8
T=temperature, i=heat index, Ep=potential evapotranspiration, N=factor depending on latitude, Ep′= corrected potential evapotranspiration, P= rainfall,
APWL=accumulated potential water loss, Ws=maximum water storage in the soil, ΔWs=Wsi-Wsi-1, Er=actual evapotranspiration ,
Q=surface runoff + infiltration
12
T=the monthly temperature ( C) and I=the annual heat index: I= ∑ i j
o
1
ij=the monthly heat index of the month j; ij=(T/5)1.514
a= 0.49239 + (1792x10-5) I –(771x10-7) I2 + (675 x 10-9) I3
Table 7: Estimated water balance at Pontokomi gauge, using Thornthwaite-Mather method.
14
The hydrologic balance of one basin is given by the following equation:
P = R + E + I + dw + dq
where: P: rainfall, R: the surface runoff, E: evapotranspiration, I: infiltration, dw: the change of
the quantity of groundwater reserves and dq: the result of human intervention
Considering the factors dw and dq as negligible, the equation becomes:
P = R+E+I
Based on aforementioned estimations the hydrological balance in alluvial aquifer (60 km2) of the
Sarigkhiol basin is listed in Table 8.
P
Percentage (%)of P
Water Volume (x106 m3)
Water hegiht (mm)
100.0
33.8
563.8
Er
72.4
24.5
408.2
I
20.6
7.0
116.3
R
7.0
2.3
39.3
Table 8: Hydrological balance in alluvial aquifer of Sarigkhiol basin (Stamou, 2001).
2.3 Geological framework
From a geological point of view (
Figure 7), carbonate rocks are mostly
distributed on the highlands and Neogene and Quaternary deposits cover the lowlands. Lignite
deposits occurring in the Plio-Pleistocene sediments (
Figure 8).
Figure 7: Geological map of the study area.
15
WATER-MAP Project
Figure 8: Stratigraphic sequence in Sarigkhiol basin (adapted from IGME).
Figure 9: Geological section in Sarigkhiol basin (adapted from IGME).
16
2.4 Hydrogeological characterisation
The main aquifer systems are developed:
in Quaternary deposits (alluvial aquifer) above lignite deposits,
in Neogene sediments developed below lignite deposits,
in carbonate rocks (karst aquifer).
The water needs of the basin, are predominantly being covered by the exploitation of both alluvial
and karstic aquifers, through a large number of boreholes (greater than 500). Water supply for the
municipality of Kozani relies mostly on karstic waters from limestones and partly on alluvial
aquifer of Sarigkhiol basin. Additionally, Sarigkhiol alluvial aquifer is partly being excavated, in
order to withdraw the lignite deposits, which lie down the overlying alluvial aquifer.
The irrigated land increased greatly in last decades, as indicated the number of wells and boreholes.
The most important limiting factor in Sarigkhiol basin is the seasonal variation in water availability
and demand. Furthermore, agriculture requires increased supplies in late spring, summer, and early
autumn, when the water availability is low.
2.4.1 Alluvial aquifer
As was mentioned above the alluvial aquifer of the Sarigkhiol basin covers an area of 60 km2 and
its maximum depth reach at 110 m below ground surface (b.g.s.) (
Table 9).
The alluvial deposits host a phreatic aquifer superimposed on successive confined or semi-confined
aquifers. There is hydraulic connection between them due to its “lens” form, as well as with the
phreatic aquifer. Despite the documented heterogeneities however, it is suggested that on a regional
scale a uniform aquifer may be considered.
Area (km2)
60
Mean altitude (m)
665
Max Depth (m below ground surface)
110
Table 9: Geometry of the alluvial aquifer.
The soil is commonly regarded as one of the principal natural factors for the assessment of
groundwater vulnerability due to the soils function as a natural protective filter in the retardation
and degradation of contaminants. Soil analyses from samples were used in order to classify the soil.
Soil profile analyses have been surveyed by Institute of Geological and Mineral Exploration
(IGME). The density of soil samples was 5 samples/Km2 and the depth 0-30 cm from the ground
surface.
Based on results from soil analyses, the predominant soil types are:
17
WATER-MAP Project
Clay, Silty-clay, Sandy-clay, Sandy-loam, Silty, Silty-loam, Loamy.
The classification of the vadose zone was based on the geological map and drilling data. For this
reason, drilling data from 119 boreholes were evaluated.
2.4.2 Groundwater balance- Piezometric surface
The water balance of the alluvial aquifer has two components: the total input or inflows (Qin) and
the total output or outflows (Qout). The equation for the groundwater balance can be written as:
Qin = Qout ± ΔS
where ΔS is the change in groundwater storage.
The total groundwater input (Qin) consists of: Rainfall recharge, Lateral subsurface inflows,
Streambed infiltration and Recharge from irrigation returns. The aquifer recharge presents
significant fluctuations, depending on the annual rainfall.
The total groundwater output (Qout) consists of Domestic water uses, Irrigation and industrial water
uses and Subsurface outflows.
The change in groundwater storage (ΔS) has been estimated by taking the difference between the
average water level at the beginning and the end of the hydrological year.
According to Stamou (2001) the mean annual input to the alluvial aquifer system is 24.2x106 m3
and the mean annual output is 30.5x106 m3 (Table 10). The recharge from karstic aquifers is
limited.
The total annual discharge for irrigation use was estimated to be 12.5x106 m3 or 41% of the total
discharge. The total discharge for domestic use was estimated to be 6x106 m3/yr or 19.6% of the
total discharge. A volume of water 12x106 m3/yr is abstracted from Public Electricity Company in
order to withdraw the lignite deposits.
Water Input
Recharge due to rainfall
Lateral groundwater fluxes
Streambed infiltration
Irrigation return
Total water input
Balance
(x106 m3 yr-1) Water Output
6.9
2.0
13.8
1.5
24.2
-6.3
(x106 m3 yr-1)
Domestic use
Agricultural use
Mine drainage
6.0
12.5
12.0
Total water output
30.5
Table 10: Groundwater balance of the alluvial aquifer of Sarigkhiol basin (Stamou, 2001).
Estimated water balance shows that the groundwater discharges from the alluvial aquifer system
exceeds the recharge, indicating that the aquifer is over-exploited through a numerous boreholes
(approximately 320). The yield of boreholes ranges between 70-150 m3/h.
18
The mean annual discharge from alluvial aquifer exceeds renewable water resources; thus the water
balance in the alluvial aquifer of Sarigkhiol basin is in disequilibrium with a deficit of 6.3x106 m3/y
(Stamou, 2001).
A decline of water table is recorded during the last decades, due to overexploitation (
Figure 10).
Koumantakis (1999) estimates a mean decline of 0.9-1.5 m/yr in the NW part and 0.6-1.5 m/yr in
the eastern part of the basin.
The depth to water table in the alluvial aquifer ranges from 7 to 75 m below ground surface or from
+585 to +730 m above sea level. It is pointed out that the groundwater level in the central part of the
basin at the beginning of 1980s was at +650 m above sea level (asl), while nowadays is at +585 m
asl.
High piezometric heights are recorded in the NE part of the aquifer and low piezometric levels are
recorded in SW (close to boreholes field of Kozani Municipality) and SE part. Due to groundwater
extraction, a cone of depression is formed close to mine in the northern part of the basin.
Groundwater flows are mainly from the North-East toward South-West, as deduced from
piezometric maps (Figure 11). Locally, in the western part of the aquifer (Pontokomi), main
groundwater flow paths are from the West toward East (Koumantakis, 1991).
1/9/1999
1/6/1999
1/3/1999
1/12/1998
1/9/1998
1/6/1998
1/3/1998
1/12/1997
1/9/1997
1/6/1997
1/3/1997
1/12/1996
1/9/1996
1/6/1996
1/3/1996
1/12/1995
1/9/1995
g ro u n d w ater level in m b .g .s.
The mean hydraulic gradient i=1.4%, as measured from the compiled piezometric maps.
0
10
20
30
40
50
60
70
80
90
Figure 10: Groundwater level fluctuation (in m b.g.s.) in alluvial aquifer of Sarigkhiol basin.
2.4.3 Hydraulic parameters
The range of hydraulic properties of the alluvial aquifer system is large, as determined from
extensive pumping test analyses (IGME, Stamou, 2001).
19
WATER-MAP Project
Transmissivity (T) and Storage coefficient (S) ranges are respectively 300-1700 m2/d and 0.7x10-2–
1.0x10-2 (Table 11).
The hydraulic conductivity (k) value ranges between 2x10-4 m/s and 8x10-2 m/s, as deduced from
the conducted pumping test analyses.
Transmissivity (T)
Storage coefficient (S)
(m2/day)
300-1700
Hydraulic conductivity (k)
(m/s)
0.7x10-2 – 1.0x10-2
2x10-4 - 8x10-2
Table 11: Hydraulic parameters of the alluvial aquifer of Sarigkhiol basin.
Figure 11: Groundwater level (m) contour map of the alluvial aquifer in Sarigkhiol basin for period May 1997
(Koumantakis, 1999 with modifications).
20
2.5 Groundwater Quality
Based on hydrochemical data, it is concluded that, the Ca-Mg-HCO3 water type is the dominant
type. High nitrate (NO3-) concentrations are locally recorded in basin. Total Hardness varies between
300-400 mg/L CaCO3 indicating that the waters are hard (IGME, 2001).
Water resources quality deterioration is exhibited as a result of anthropogenic activities. Untreated
waste effluent from industrial and livestock units and waste water treatment plant shortage form
major pollution sources of surface water bodies; these circumstances are responsible in conjunction
with the agricultural activities for the groundwater quality degradation.
Groundwater quality deterioration is also caused by the discharge of liquid and solid waste directly
into abandoned shallow wells in urban areas or abandoned quarries in rural areas. Central municipal
sewage-treatment systems do not exist in small towns. Fertilizers and agricultural chemical
compounds are being used intensively to maintain the productivity of the soil. Agricultural impact
on groundwater quality has been mostly associated with nitrate pollution.
2.6 References
Dimitrakopoulos, D., 2001. Hydrogeological conditions of Amyntaion pit. Doctoral Thesis,
Technical University of Athens. Dept. of Mechanical and Metallurgical Eng. 204 pp.
Institute of Geological and Mineral Exploration (IGME), 2001. Quality control and hydrogeological
study of Western Macedonia. IGME, Technical report (Unpublished).
Institute of Geological and Mineral Exploration (IGME), 2001. Soil and Soil-chemical study of
Kozani-Ptolemaida-Amyntaion region. Technical report (Unpublished).
Quality control and hydrogeological study of Western Macedonia. IGME, Technical report
(Unpublished).
Koumantakis, J., 1999. Assessment and water resources management in Sarigkhiol basin, Kozani
prefecture. Technical report. National Technical University, Athens (in Greek, Unpublished).
Patsios, E., 2007. Application of DRASTIC method to assess the groundwater vulnerability: A case
study from alluvial aquifer of Sarigkhiol basin. M.Sc. dissertation submitted to Dept. of
Geology, Aristotle University of Thessaloniki (supervisor K. Voudouris).
Stamou A., 2001. Hydrogeological study of the alluvial aquifer in Sarigkhiol basin. Institute of
Geological and Mineral Exploration (IGME) (in Greek).
Voudouris, K., Patsios, E., 2007. DRASTIC method to assess groundwater vulnerability.
Experiences from its application in Greek test sites. Oral presentation. Meeting in the frame of
INTERREG III B project, Bari, Italy.
21
WATER-MAP Project
3 Hydrometeorological and Hydrogeological data of Florina basin,
Florina prefecture, Western Macedonia region, Greece
N. T. Kazakis, K. S. Voudouris
Lab. of Engineering Geology & Hydrogeology, Dept. of Geology, Aristotle University of Thessaloniki, 54124
Thessaloniki, Greece. Email: [email protected]
Florina basin (
Figure 12) is located in the central part of Florina Prefecture, Western Macedonia
region, Greece, covering an area about of 319 km2.
The mean altitude of the basin is about 620 m asl and the mean slope 1.5% (Table 12). In the area
two aquifer systems can be distinguished, one alluvial aquifer covering an area about 180 km2 and a
second one in Neogene deposits covering an area about 149 km2 .
Figure 12: Location of the Florina basin (www.google.earth)
22
At the west side there is Barnous Mountain, at the east side there is Boras Mountain, at the south
side there is Bernon Mountain (Figure 13).
The land is used mainly for cultivation of cereals and cows and sheep graze the area. In a large part
of the area irrigated agriculture is practiced. Lignite deposits occurring in the basin.
Area (km2)
Maximum altitude (m)
Mean slope (%)
319.0
600.0
660.0
1.5
Table 12: General characteristics of the Florina basin
Figure 13: Topographical map of the study area.
The area is characterized by a semi-arid, Mediterranean climate, with an annual temperature of 12.58
°C and an annual rainfall of 471.65 mm (Table 13 and Table 14). About 70-80% of annual rainfall
occurs in wet period, while summers are usually dry.
23
WATER-MAP Project
1
J
F
M
26.39 25.73 30.79
A
50.6
M
J
J
A
S
O
N
D annual
61.29 31.41 25.92 33.56 41.12 54.72 51.52 40.16 471.65
Table 13: Mean monthly rainfall (mm) at Kalliniki stasion for period 1974-2004.
gauge
Kalliniki
J
F
M
A
M
J
J
A
S
O
N
D
1.7
4.3
7.7
11.1
16.1
20.8
23.0
22.9
19.4
14.1
8.1
3.8
annual
12.58
Table 14: Mean monthly temperature (oC) at Kalliniki gauge for period 1974-2004
From a geological point of view (Figure 14), carbonate and crystalline rocks are mostly distributed
on the highlands and Neogene and Quaternary deposits cover the lowlands. Lignite deposits
occurring in the Plio-Pleistocene sediments. On the west highlands, granite covers the bigger part of
the region.
Figure 14: Geological map of the study area.
24
3.4 Hydrogeological characterisation
The main aquifer systems are developed:
1) in Quaternary deposits (alluvial aquifer)
2) in Neogene sediments
3) in carbonate rocks (karst aquifer)
The water needs of the basin are predominantly being covered by the exploitation of both alluvial
and karstic aquifers, through a large number of boreholes. The irrigations needs of region are
covered by drillings that exploit the alluvial aquifer. On the other hand D.E.H. (NATIONAL
ELECTRICAL COMPANY) covers her needs for water from karstic aquifer.
3.5 Data Collection
The following data were collected:
a) 60 lithological profiles from boreholes,
b) 46 water table measurements,
c) Data from 3 rain gauge gauges,
d) Temperature data from 3 gauges,
e) Soil analyses from 300 samples,
f) Estimation of transmissivity from 45 pumping tests.
Figure 15: Water table measurement points on the Florina basin.
25
WATER-MAP Project
3.6 References
•
Mountrakis D., (1985), Geology of Greece, University Studio Press, 204 pp.
•
Basiliadis G. (2005), Hydrogeological research of Northwest basin of Florina, 75 pp.
•
Koumantakis I. (1995), Hydrogeological research of Florina prefecture, 64 pp.
26
4 Hydrometeorological and Hydrogeological data of Monopoli area
(Apulia, south-eastern Italy)3
4.1 Location-Description of the area
From a methodological point of view, any type of data used in this chapter is implemented on
specific relational geo-databases, realised to permit spatial analysis of data with GIS tools.
Any kind of spatial determination is realised on the basis of squared cells 10 m wide. This is
wideness of the smallest spatial unit defined for the final vulnerability assessment.
The study area is located in the Apulia (Puglia) region in south-eastern Italy (Figure 16 and Figure
17).
Its boundaries are:
W= lon 17° E
E=lon 17°20”E
S= lat 40°41”30”“ N
N=Adriatic sea coast
The extension of the study area is 1039.3 km2, mainly belonging to the Province of Bari (869.2
km2). 9.0 km2 at the south-eastern border are located in the Province of Brindisi, and 161.0 km2, at
the southern border, are in the province of Taranto. The area includes entirely 6 municipalities
(Figure 18), belonging to the province of Bari: Mola di Bari, Polignano a Mare, Conversano,
Catellana Grotte, Noci, Alberobello; the municipalities of Bari, Rutigliano, Turi, Noicattaro,
Putignano, Monopoli, Locorotondo and Gioia del Colle (province of Bari) are partially included as
the municipality of Fasano (province Brindisi), Mottola and Martina Franca (province Taranto).
3
Chapter realised by CNR–IRPI, Istituto di Ricerca per la Protezione Idrogeologica, Via Amendola 122/i, 70126 Bari,
Italy. Authors: Polemio M. (Scientific person on charge), Casarano D., Dragone V., Limoni P.P., Santaloia F., email:
[email protected]
27
WATER-MAP Project
Figure 16: Location of the study area.
Figure 17: Study area
28
Figure 18: Detail of the study area with municipalities.
The length of the coastal line included in the area is about 38 km; and the maximum distance from
the sea (Adriatic or Ionian) does not exceed 30 km.
The maximum elevation is 547 m asl, with an average elevation of 282 m asl (Figure 19). The
slopes is generally low (<6°) except where morphological scarps are observed, where the slope is
greater than 12° Figure 20.
4.2 Meteorological features
Climate is typically Mediterranean; summers are warm and generally dry, winters are wetter but
mild. The average annual temperature at the sea level is around 17 °C, ranging from 9 °C in January
and 25 °C in July and August. The mean annual rainfall is about 600 mm, mainly concentrated in
winter and autumn. Snow is an exceptional event at the sea level, while it occurs sometimes at the
highest altitudes.
For the description of temperature and rainfall distribution over the study area, and for the
calculation of evapotranspiration and net rainfall, data from 8 rain gauges (6 also with temperature
data) located in the study area; 3 adjacent rain gauges were also considered (Table 15).
29
WATER-MAP Project
Figure 19: DEM of the study area (m asl).
Figure 20: Slope map (white= <3°, green=3-6°, pink=6-12°, brown=>12°).
30
Rain and
temperature gauge
Casamassima
Castellana Grotte
Conversano
Fasano
Locorotondo
Noci
Polignano a Mare
Turi
Bari
Gioia del Colle
Ostuni
Lat.
Long.
40°57”
40°53”
40°58”
40°50”
40°45”
40°48”
41°00”
40°55”
41°07”
40°48”
40°44”
16°55”
17°10”
17°07”
17°22”
17°20”
17°07”
17°13”
17°01”
16°52”
16°55”
17°35”
Height
(m asl)
223
290
219
111
420
420
24
250
12
360
237
Rain data
from
1960
1923
1921
1922
1837
1921
1927
1928
1885
1921
1921
Temp.
data from
1960
1958
1965
1924
1935
1935
1924
1935
Table 15: Rain and temperature gauges.
For each month, rainfall maps were derived from the interpolation of rain gauge data.
The mean annual rainfall (Figure 21) ranges from 580 mm (in the northern coast area) to 680 mm
(on the most southern inner areas). It generally increases with the elevation and the distance from
the sea. An increment is also observed along the coast to south-east. The rainiest months are
November and December (the spatial range of these two months is equal, from 70 to 95 mm as
monthly average), the driest is July (the spatial range is 13-25 mm). If seasons are considered,
winter rainfall (December-February) is the highest (spatial range 195-245 mm), followed by autumn
rainfall (180-225 mm in the period September-November). The driest season is summer (the spatial
range is 60-85 mm between June and August). The average rainfall of spring (March-May) is
variable from 130 to 160 mm in the study area. The highest rainfall values are always recorded in
the inner areas, except for winter, when the direct effect of the Adriatic sea is prevalent.
The effect of altitude has to be kept into account in the interpolation of temperature point values to
produce monthly temperature maps obtaining realistic results.
For each monthly average, the values of the mentioned temperature gauges were plotted as
functions of altitude, and a linear fit was calculated. To obtain better correlation it was chosen to
consider only the gauges inside the study area and the adjacent gauges closest to the Adriatic coast.
Data from innermost gauges, or closest to the Ionian coast showed a worst fit to the linear trend. For
each month, the dependence of temperature from altitude was expressed as a coefficient expressed
as °C/(100 m), the angular coefficient of the linear regression line.
31
WATER-MAP Project
Figure 21: mean annual rainfall map.
The lowest gradient is observed for winter months; the coefficient ranges from -0.38°C/(100m) of
June to -0.78°C/(100m) of January. The regression line fits so well the effect of altitude each month
that the distance from the sea can not be considered.
To generate the maps, known the temperature at sea level on the basis of the linear regression, the
effect of altitude is determined for each cell with the DEM applied to the regression line.
The resulting average annual temperature ranges from 13.6°C to 16.7°C (Figure 22); the monthly
average temperature of January ranges from 5.5°C to 9.3°C (Figure 23), the monthly average
temperature of July and August range from 22.7°C to 25.0°C (Figure 24).
32
Figure 22: mean annual temperature map (°C).
Figure 23: monthly mean temperature map of January (°C).
33
WATER-MAP Project
Figure 24: monthly mean temperature map of July (°C).
The evaluation of Net Rainfall was performed as a preliminary step to calculate the annual
infiltration. Turc”s formula, modified using the so-called “corrected temperature” Tp, was used,
employing monthly average rainfall and temperature, following the expressions:
(
E r = P / 0.9 + P 2 / L2
)
L = 300 + 25T p + 0.05T p3
Tp = ∑ PiTi / P
where Pi and Ti are the precipitation height and the temperature of month I (i from 1 to 12) and Er
and P are the mean annual value of real evapotranspiration and of rainfall.
Over the study area, the mean annual value of real evapotranspiration ranges between 480 and 520
mm, and the net rainfall ranges between 88 and 186 mm (Figure 25): the geographical trend of
precipitation is confirmed and enhanced by the effect of altitude on temperature, decreasing
evapotranspiration and so proportionally increasing net rainfall.
34
Figure 25: map of mean annual net rainfall (mm).
4.3 Geological setting
Apulia represents the extensive foreland of the Apennine orogen, active during the Neogene
(Southern Italy, Figure 26) and part of the Adriatic plate which corresponds to the Northern
prominence of the African promontory (Ciaranfi et al., 1988). This foreland is weakly deformed and
consists of emerged domains (the Gargano, the Murge and the Salento areas; Figure 26) and of a
submerged area in the Adriatic Sea and in the Ionian Sea (Auroux et al., 1985).
The Apulian foreland shows a rather uniform structure with a Variscan crystalline basement
(continental crust) and an approximately 6 km thick Mesozoic sedimentary cover (Ciaranfi et al.,
1988, Doglioni et al. 1994). This cover was drilled by exploration wells, as Puglia 2 in Murge area.
This well shows Permo-Triassic fluvial-deltaic terrigenous deposits, Triassic anidiritic-dolomitic
succession (Burano Anidride) and a well-bedded Jurassic-Cretaceous carbonate platform
(D”Argenio, 1974), moving from the bottom to the top of the well. In Murge and Salento areas
(Ciaranfi et al., 1988), the Cretaceous successions (Calcare di Altamura and Calcare di Bari
Formations) are overlain by thin, discontinuous Tertiary deposits represented by organogenic
and/or calcarenitic deposits (Paleocene-Oligocene; Calcare di Castro and Calcareniti di Porto
Badisco Formation) and by carbonate-terrigenous sediments (Neogene sediments as Pietra Leccese,
35
WATER-MAP Project
Calcareniti di Andrano, Leuca and Sabbie di Uggiano Formations; Pliocene-Quaternary deposits as
Calcarenite di Gravina, Argille subappennine, Sabbie di Monte Marano, Conglomerato di Irsina
Formations and Terraced marine deposits).
According to Tropeano et al. (2001), up to Late Pliocene-Early Pleistocene times, the Apulian
foreland was subjected to subsidence, as recorded by the basal transgressive carbonate succession,
known as Calcarenite di Gravina Formation deposited on the Cretaceous carbonate platform
(Ciaranfi et al. 1979; Iannone and Pieri, 1982) and by the overlain silty-clayey succession (Argille
subappennine Formation). This regional subsidence was also influenced by the eastward rollback of
the subducting Adria plate and the progressive eastward migration of the south Apennines orogenic
system (Malinverno and Ryan, 1986; 1987; Doglioni, 1991). Moreover, during this subsidence, the
sedimentation was influenced by the underlying geological structure of the Apulian platform, which
was characterized by a horst and graben system, so the wide exposed Apulian foreland
progressively became a large drowning archipelago during the transgression (Tropeano et al.,
2000). After submersion, island flat-tops became isolated small platforms (Tropeano et al., 2000).
Since Early Pleistocene time both the south Apennines foredeep (Bradanic trough) and the adjacent
foreland were affected by uplift (Tropeano et al., 2000, 2002) due to the arrival at the subduction
hinge of the thick buoyant south-adriatic continental lithosphere, which caused a lower penetration
rates of the slab and a consequent buckling of the lithosphere (Doglioni et al., 1996). The same
horst and graben system, governed distribution of lands and seas during this relative sea-level rise
(Tropeano et al., 2000). The general uplift of the trough and part of the adjacent foreland is testified
by the deposition of regressive coastal deposits (Sabbie di Monte Marano and Conglomerato di
Irsina Formations of Early-Middle Pleistocene in age and the Terraced marine deposits of MiddleLate Pleistocene). In particular, the oldest regressive deposits outcrop only along the South-Western
margin of Murge while the Terraced marine deposits outcrop extensively or in limited limbs in
Murge and Salento lying in transgression on distinct abrasion surfaces located at different highs.
The uplift of the Murge is so testified by the presence of 16 orders of uplifted shorelines, recorded
by palaeocliffs, abrasion platforms and/or by thin Terraced marine deposits, that disconformably
overlay the Mesozoic limestones and the Late Pliocene-Early Pleistocene units of the Murge
(Ciaranfi et al., 1988; Doglioni et al., 1996).
From a structural point of view, the Apulia region corresponds to the most uplifted portion of a
wide antiform structure with a WNW-ESE trending and segmented by several, parallel normal
faults and related transfer zones (Doglioni et al. 1994). The antiform shows down faulted blocks
both toward the Bradanic trough to the west and toward the Adriatic (Figure 26). Transfer faults
oblique or perpendicular to the main WNW trending normal faults divided the region in three main
36
blocks with different degree of uplift, from the highest Gargano to the lowland of Salento moving
toward the southeast (Doglioni et al., 1994)
The study area (Monopoli area) is located along the vertical Adriatic coastal cliffs at the south of
Bari town (Figure 27). These cliffs represent part of the faulted blocks of the eastern margin of the
Murge domain, lowered to the Adriatic Sea. The Calcarenite di Gravina, outcropping in the
Monopoli area, discordantly covers the carbonate sequences of the Calcare di Bari (Figure 27;
Ciaranfi et al., 1988) Inwards, for instance at Cristo Re or Santa Lucia districts (Figure 27), the
Calcare di Altamura occurs on the Calcare di Bari from which is separated by an unconformity
Turonian in age (Ciaranfi et al., 1988).
In detail, the Calcarenite di Gravina (Late Pliocene?-Lower Pleistocene; Iannone & Pieri, 1979,
Ciaranfi et al., 1988) is composed of bioclasts and terrigenous limestone fragments, some of them
derived from the erosion of the underlying Cretaceous rocks, therefore it consists of thick banks of
biocalcarenites and biocalcirudites with some calcilutite levels. Continental calcareous silts and
clays are locally present in some land hollows at the base of the calcarenite banks. This formation
provides coarse-grained, clastic basin-margin, shoreline to offshore facies, so their carbonates are
mainly shallow-marine deposits which structures and lithologies display evidence of strong
transgression onto a karstic region previously dissected in a complex horst and graben system
(Tropeano et al., 2000, 2002). The Calcare di Altamura Formation (Late Turonian?-Maastrichtian)
consists of micritic limestones, rich in micro and macrofossils (rudists mainly as macrofossils),
locally forming cyclic sequences thick about 1000 meters. This formation, represented mainly by
biogenic fine limestones, is separated from the underlying Calcare di Bari, as above-mentioned, by
an unconformity locally associated with continental sediments as bauxite and/or sandy-clayey
deposits (Ciaranfi et al., 1988). The Calcare di Bari Formation (Valanginian-Lower Turonian?)
consists nearly 2000 metres of micrites and dolomitic limestones, with some levels rich in
macrofossils (mainly rudist-rich beds) of rudists and microfossils (Ciaranfi et al., 1988). Therefore,
this formation is represented by a thick sequence of mostly detritic limestone layers and some
dolomite levels. The carbonate successions of the Cretaceous formations show similar
paleoenvironmental conditions with tha characters of a wide inner carbonate platform, subjected to
subsidence compensated by shallow-marine sedimentation. This sedimentation was characterised by
several, cyclic tidal fluctuations and the rudist-rich beds created themselves during the positive
marine levels (Ciaranfi et al., 1988). Moreover, Holocenic terra rossa deposits from limestone
solution and alluvial deposits occur in depressed areas such as dolines and river valleys (Merla and
Ercoli, 1971).
37
WATER-MAP Project
a)
b)
A
SW
Tyrrhenian
Sea
c)
Foredeep
Southern Apennines
(Bradano Trough)
Apulian
Foreland
NE
Adriatic
Sea
a.s.l.
0
-4
km
Section A
0 km 20
-7
1
2
3
4
5
Figure 26: a) Schematic structural map of Italy showing location of Apulian foreland and the cross section A (after
Doglioni, 1994, modified); b) schematic geological map of the Puglia region (after Pieri et al., 1997, modified; c)
schematic geological cross section A through the entire southern Apennines thrust belt-foredeep-foreland system (after
Sella et al., 1988, modified). Key: 1) internal Apenninic nappes (Liguride-Sicilide Complexes), 2) Apennine Platform
Units, 3) undifferentiated Lagonegrese-Molise Units, 5) Bradano Trough Unit, 8) Apulian Platform Units.
Alluvial and
beach deposits
Calcarenite di Gravina
Formation
AD
RI
AT
IC
Calcare di Altamura
Formation
SE
A
Calcare di Bari
Formation
Coastlines
Coastal dune
a
b
Axis of anticline (a)
and synclinale (b)
Fault
(dashed if inferred)
5 km
Regional
strata attitude
Figure 27: Geological map of the study area (after Ciaranfi et al., 1988, modified).
38
4.4 Collection of data: database and preliminary statistical processing
Geological, hydrogeological and chemical-physical groundwater data of 250 boreholes have been
collected (Figure 28). The wealth of information assembled has been extracted from a vast array of
sources (from public sources or institutions and secondly by private companies) and dates back to
various periods of time. Hence, huge efforts have been put to make data comparable and
overlapping and validate the findings in keeping with the objectives of this research activity.
The location, the altitude, the depth and the source of each well have been so gathered in detailed
databases where stratigraphical, piezometric and chemical-physical groundwater data have been
also considered.
The selected boreholes are widespread all over the study area; someone is near but outside the area
limit (Figure 28). In short, Table 16 describes the type of data and some statistic concerning the
stratigraphical and hydrogeological data.
Moreover, historical data and direct current measurements have been also collected for estimating
the groundwater use and the salt-related groundwater quality degradation due to seawater intrusion.
The attention is focused on some major elements, such as calcium, magnesium, sodium, potassium,
carbonates, bicarbonate, chlorides, sulphates, nitrates and some other chemical-physical (total
dissolved solids, salinity, electrical conductivity, pH and temperature) and microbiological
parameters, such as streptococci and total and faecal coliforms. The chemical-physical data will be
detailed described and discussed in another Report.
A deep analysis of the all data, connected also to a hydrogeological survey, has allowed defining the
geological and hydrogeological set-up of the study area. Besides, the hydrogeological features of
aquifer lying in the area have been also pointed out.
The attention is focused on the so-called deep carbonate aquifer lying in a wide portion of the
region, called Murgia Plateau.
In order to manage space-related information via a GIS, relational geo-databases have been
designed to permit the analysis using all type of data. In the database have been recorded, where the
information is available, for each well: the location, the geometry and the depth of the well, the
piezometric level (asl), the depth to groundwater and data concerning well pumping tests. These
parameters have yielded some additional data which have helped characterising the aquifer under
study, such as the depth to groundwater, the thickness of the unsaturated zone and of saturated
aquifer, the hydraulic conductivity and the type of groundwater flow.
The record of data pertaining to one of the 250 surveyed wells is identified by the progressive
number of the well itself. As the major characteristic of a GIS is its ability to assign every element
39
WATER-MAP Project
its actual spatial coordinates, the wells have been geo-referenced in the Gauss Boaga system based
on the topographic maps of the study area on a scale of 1:25,000 using software del tipo ArcViewArcMap.
The statistical processing of collected data was based on the various parameters featured in the
database of which Table 16 provides a statistical outline of the major hydrogeological parameters.
Briefly, stratigraphical and constructive data are available for 92% of the wells. The depth of the
surveyed wells varies from a few metres to hundreds of meters, up to max. 853 m. Along the
Adriatic coastline the wells are generally shallow; they become deeper inland. The wide range of
well depth is not due only to altitude variability but also to the vertical location of strata with higher
permeability which, due to karstic processes, is widely located tens of meters below the present sea
level.
Well pumping tests are available for 86% of wells; the discharge of each well ranges from.1 l/s to
40 l/s; the mean value corresponding to 18 l/s; the mean drawdown to obtain these discharges is
equal to 22 m. It is possible to observe, from the interpretations of pumping tests, that the
groundwater flow is generally confined in the study area.
At the end, the hydrogeological data are available for the 47% of wells and they will be discuss in
the following section.
.
Well depth
(m)
Data %
MIN
MEAN
MAX
92
9
412
853
Piezometric
Pumping
Aquifer Hydraulic
Depth to
Drawdown
level
test
thickness conductivity
groundwater
(m)
(m)
(m asl)
(l/s)
(m/s)
85
0.5
34
181
47
37
227
452
86
1.5
18
40
86
0.1
22
159
47
1
56
262
47
2.E-06
8.E-03
7.E-01
Table 16: Statistic of the main hydrogeological parameters of collected data (250 record or total number of selected
wells).
40
•
•
•• •
•
••
•
• •
•
••
•
•
•••
•
•• •••• •
•
•
•
•
••
••
•
• • •
•
•
• •• • •
•
• •••••• ••
•
•
•
•
•
•
•
•
•
•
•
• ••
•
• •
•
•
•
•
•
•
•• • •
•
•
• ••
••
•
•••
••
•
•
•
•• •
• ••
• • ••
•• • • •••• ••
• • • • • ••
••
•
• • ••
•
•
• • ••
• • ••
• •
•
•• •
• •
•
•
•
•
•
•
•
•
•
•
• •
•
•
•
•
• ••
•
•
•
•
•
•
•• •
•
•
•
•
• •
••
•
•
• • • • ••
••
•
•
• ••
• •
•
•
•
•
•
•
•
•
•
•
•••
•
•
•
•
•
•
•
•
•
•
•
Well
Study area.
•
Figure 28: Well location maps.
4.5 Hydrogeological features
In the Apulia region can be mainly distinguished the hydrogeological units of the Gargano and of
the Tavoliere and the hydrogeological structures of the Murgia and of the Salento (Figure 29). All
of these areas are carbonate in nature, except for the Tavoliere, and constitute the largest coastal
karstic aquifers of Italy, made up of Mesozoic rocks (Polemio, 2005).
41
WATER-MAP Project
Figure 29 - Apulian hydrogeological structures and units. 1) Carbonate rock outcrops of Gargano Unit, Murgia and
Salento Structures; 2) Tavoliere Unit, shallow aquifer mainly constituted by conglomerate and sands; 3) shallow aquifers
and permeable lithotypes, calcarenites, clayey sands, sands, gravel, or conglomerates; 4) low permeable lithotypes, blue
marly clays; 5) hydrogeological boundary, dashed where uncertain; 6) regional boundary; 7) provincial boundary; 8)
study area.
The karstic coastal aquifer in the study area belongs to hydrogeological structure of Murgia. The
Murgia (maximum altitude 680 m asl) is a large asymmetric horst, hit by two direct fault systems
(NW-SE and NE-SW), due to neotectonics. Because of these faults, the morphological structure
slopes down towards the Adriatic Sea and towards the adjoining regions by means of a succession
of ledges in the shape of steps, bounded by slight fault throws.
The aquifer consists of platform cretaceous limestones covered with a thin layer of plio-quaternary
calcarenites. The carbonate rock is bedded, jointed and subject to karst phenomena. Freshwater
lying on seawater flows along preferential pathways where rock permeability is greatest, depending
on the highest fracturing degree.
The whole study area is characterised by developed karst landforms which formed a network due to
the chemical dissolution of limestone; karst formed in response to several morphogenetic phases
which took place in different climatic and structural contexts (Grassi, 1983). As a result an
underground network of cavities, caves and conduits is developed; some of these have great
dimensions. The landscape is characterised by many dolines, valleys and not so clearly defined
drainage lines, creating a discontinuous network (Figure 30). Dolines are of different dimensions
and they are either quite circular or elongated in one direction; in some cases they are coalescent
and they form an endorheic basin.
The valleys and water lines are the remnants of the original hydrographic network (Parise 1999) and
are mainly directed to the NE. Today karst is exclusively due to rainfall since there is no permanent
superficial drainage system in the whole area.
42
It follows that the repeated vertical motions, which have occurred during the different stages of the
Paleotectonics and Neotectonics, have led the karst aquifer to migrate many times and to a various
extent, both upwards and downwards (Grassi, 1983). In order to hydraulically offset these motions,
the groundwater network (mainly over the past 70 thousand years) has undergone major changes,
since it has had to adjust to the overall regional motion and to the differential motions between the
blocks of the same platform. In addition, the changes in the basic levels have led to different effects
according to the areas, owing to the magnitude and the frequency of the local events.
The karstic coastal aquifer is multilayered for the variable distribution of fractured and permeable
strata confined between impermeable levels of various extension and thickness, due to tectonic
events that has fractured the carbonate mass in a poor and discontinued manner.
It is possible to observe, from the interpretations of pumping tests, that the groundwater flow in the
area is generally confined, except along a narrow coastal strip; faults govern the major preferential
flow paths and seawater intrusion.
The map of piezometric surface (Figure 31) shows that starting from the main recharge area, located
in the highest portion of the study area, groundwater, with an initial piezometric level slightly
higher than 100-150 m asl, flows toward the coast, where discharge diffusely to the sea. The main
groundwater flow path is mainly towards the Adriatic coastline; the piezometric gradient is high,
also equal to 1-1.5 % or greater far from the coast.
The high anisotropy and unhomogeneity degrees differentiate the aquifer so that groundwater
circulates following preferential pathways with relevant differences from within short distances.
This is the reason for which the thickness of the aquifer, for which is known, is really irregular,
ranging from 1 m to 262 m) , as a consequence of the irregular surface of aquifer bottom and top
but also due the discontinuous thickness of high permeable limestone strata.
The depth to groundwater (Figure 32) is really high (greater than 400 m) in the main recharge area
and decrease towards the coastline.
The high variability of hydrogeological characteristics is confirmed also from distribution of
hydraulic conductivity (Figure 33); data on 118 well tests are been collected for the area (47% of
total wells). The minimum hydraulic conductivity is equal to 2 10-6 m/s, the detected maximum is 7
10-1 m/s and the mean value is 8 10-3 m/s.
The data density and the homogeneity is almost low in the case of hydraulic conductivity in the
recharge area; so that the mean value is strongly related to the major well tests in the coastal area.
In any case any consideration can be done. The hydraulic conductivity increases coming from
inland, where the wells discharges are quite low and the drawdown are the highest, to the coast
where the hydraulic conductivity is the greatest, depending on relevant effects of karstic processes.
43
WATER-MAP Project
Due the low density of available data in the main recharge area, for the next applications of
vulnerability assessment tools a detailed study area will be selected inside the whole study area.
Figure 30: Distribution of karst landforms (dolines) and drainage network.
44
0.5
2.5
5
10
25
50
75
100
150
Figure 31: Map of piezometric contour lines (m asl).
45
WATER-MAP Project
50
100
200
300
400
Figure 32: Map of depth to groundwater (m).
46
1)
2)
3)
Figure 33: Hydraulic conductivity contour map (m/s). 1) 0.01m/s, 2) 0.001m/s, 3) 0.0001m/s.
47
WATER-MAP Project
4.6 References
Auroux C., Mascle J., Campredon R., Mascle G. & Rossi S. (1985) - Cadre géodynamique et
évolution récente de la Dorsale Apulienne et de ses bordures. Giornale di Geologia, 3, 47 (1/2),
101-127.
Ciaranfi N., Pieri P. & Ricchetti G. (1988) – Note alla carta geologica delle Murge e del Salento
(Puglia centromeridionale). Mem. Soc. Geol. It., 41 (1), 449-460.
Doglioni C. (1991) - A proposal of kinematic modelling for W-dipping subduction - Possible
applications to the Tyrrhenian Apennines system. Terra Nova, 3, 423-434.
Doglioni C. (1994) - Foredeeps versus subduction zones. Geology, 22, 271–274.
Doglioni C., Mongelli F. & Pieri P. (1994) - The Puglia uplift (SE Italy): an anomaly in the foreland
of the Apenninic subduction due to buckling of a thick continental lithosphere. Tectonics, 13
(5), 1309–1321.
Doglioni C., Tropeano M., Mongelli F. & Pieri P. (1996) – Middle-Late Pleistocene uplift of
Puglia: an “anomaly” in the Apenninic foreland. Mem. Soc. Geol. It., 51, 101–117.
Grassi D. (1983) - Difformità di ambiente idrogeologico promossa in seno alla piattaforma
carbonatica appula da una evoluzione tettonico-carsica differenziata. Geol. Appl. e Idrogeol.,
XVIII, parte I, 209-239, Bari, Italy.
Iannone A. & Pieri P.(1979) - Considerazioni critiche sui “Tufi calcarei”delle Murge. Nuovi dati
litostratigrafici e paleoambientali. Geografia Fisica e Dinamica Quaternaria, 2, 173–186.
Malinverno A. & Ryan W.B.F. (1986) - Extension in the Tyrrhenian Sea and shortening in the
Apennines as result of arc migration driven by sinking of the lithosphere. Tectonics, 5, 227-245.
Merla G. & Ercoli A. (1971) - Note illustrative della Carta Geologica, Foglio 190, Monopoli. Serv.
Geol. Ital., Roma, pp. 23.
Parise, M.(1999), Morfologia carsica epigea nel territorio di Castellana Grotte, Itinerari
Speleologici, 8, 53–68.
Pieri P., V. Festa, Moretti M. & Tropeano M. (1997) – Quaternari tectonic activity of the Murge
area (Apulian foreland-southern Italy). Annali di Geofisica, 40 (5), 1395–1404.
Polemio M. (2005) - Seawater intrusion and groundwater quality in the Southern Italy region of
Apulia: a multi-methodological approach to the protection. UNESCO, IHP, n. 77, 171-178,
Paris.
Sella M., C. Turci & RivaA. (1988) - Sintesi geopetrolifera della Fossa Bradanica. Memorie della
Societa` Geologica Italiana, 41, 87–108.
Tropeano M. & Sabato L. (2000) - Response of Plio-Pleistocene mixed bioclastic-lithoclastic
temperate-water carbonate system to forced regressions; the Calcarenite di Gravina
Formation, Puglia, SE Italy. In: Sedimentary Responses to Forced Regressions. Geol. Soc.,
London, Spec. Publ., 172, 217-243, Ed. Hunt & Gawthorpe.
Tropeano M., Sabato L. & Pieri P. (2002) - Filling and cannibalization of a foredeep: the Bradanic
Trough (Southern Italy). In: Sediment Flux to Basins: Causes, Controls and Consequences.
Geol. Soc. London, Spec. Publ. 191, 55-79, Eds. Jones & Frostick .
48
5 Hydrometeorological and Hydrogeological data of Piana del Fucino,
Abruzzo region, Italy4
5.1 General description
Basin Authority of Rivers Liri-Garigliano and Volturno has decided to develop WATER MAP
project in basin of Fucino (Figure 34). The Plain of the Fucino is an extended flat area, a time
location of a very large lake at present drained, located entirely in the territory of the Abruzzo
Region. The basin of Fucino has a flat area, between 648 and 700 m asl, included in a mountainous
zone with peaks that reach 2500 m asl. The Plain has an extension of about 324 km2, while the
comprehensive surface of the drainage basin of the Fucino is of about 845 km2.
Borders of study area are:
− on the North Monte Velino
− on the Nord-East Monte Sirente
− on the East Monte S. Nicola e Passo di Forca Caruso
− on the South-East Passo del Diavolo e Monte Rapanella
− on the South Monte Rovella
− on the South-West Monti Simbruini
− on the North-West Monti Carseola.
4
Chapter realised by Autorità di Bacino dei fiumi Liri – Garigliano e Volturno
49
WATER-MAP Project
Figure 34: Fucino Basin
The plain, in which flow into the Giovenco River, has no natural bayou and, in the past (XIX
century), within the plain there was a large lake, with a surface about 160 km², which has been
drained.
Into the basin there are 27 municipalities, and 18 are almost entirely included in Liri-Garigliano
basin. Most important municipalities are located around the plain (Avezzano 39376 inhabitants,
Celano 10979 inhabitants), and a little number of people lives in municipalities located in mountain
zone.
The most important economic activity of Fucino Plain is agriculture, but there is an important
industrial area in Avezzano. In the last years new cultivations has been introduced in Fucino area, in
particular vegetables instead of sugar beet. Water demand for agriculture increased due to this land
use transformation, so it is very important to define a water resources government strategy for a
sustainable use, on the environmental and social point of view.
5.2 Acquired data for Fucino plain
Characterization of study area has been based on data collected from scientific papers and from
other studies. Aim of characterization is to support vulnerability map realization and to define
actions for a Water Resources Government Plan, as defines in Water Framework Directive. Basins
Authority has programmed also a fieldworks campaign in order to increase knowledge of study area
physical features.
This document explains briefly all activities realized by technical staff of Basin Authority, activities
deputed to acquire data for WATER MAP project development. Acquired data are related to:
•
Hydrology and climatology (Meteorological aspects),
•
Geology,
•
Hydrogeology,
•
Pollutant loads,
•
Waste water treatment.
50
5.3 Meteorological aspects
Fucino Plain is characterized by a continental climate, with intensive rainfall during the winter and
dry-season during the summer.
5.3.1 Rainfall
To develop the hydrological characterization, the LG Authority has realized a data processing of
values acquired in 28 gauges (15 internal and 13 external to the basin) from 1921 to 2003 (Figure
35).
Figure 35: Fucino Basin and rainfall measure gauges.
The most relevant result of hydrological analysis is the definition (based on 82 years of
observations) of annual medium rainfall map (Table 17 and Figure 36), and the medium rainfall
map for each month (Figure 37).
The minimum value of rainfall is about 650–700 mm/y in the plain and the maximum value is more
than 1400 mm/y, on the mountains in the South of Fucino Basin.
51
WATER-MAP Project
GAUGE
Est_UTM33 Nord_UTM33
Elevation
[m asl]
years
Annual
average
rainfall
[mm]
Avezzano (E. F.)
369188
4654952
698
29
629.0
Avezzano (S. I.)
369299
4655999
708
75
774.7
Balsorano (E. F.)
379954
4630451
400
45
1321.0
Bisegna (E. F.)
397060
4641999
1216
51
917.9
Capistrello
366725
4647532
735
80
1233.4
Cappadocia
357628
4652028
1098
73
1423.5
Cerchio
384125
4658333
834
50
644.5
Civita d'Antino
373148
4638405
893
59
1410.1
Cocullo
398689
4654160
870
48
968.4
Fucino (Borgo V. N. )
371914
4653051
663
10
716.6
Fucino (STR. 28)
387120
4645728
662
17
664.2
Fucino (STR. 39)
374569
4645960
664
5
777.5
Fucino 8000
379831
4650475
652
80
729.4
Gioia Vecchio
395066
4639560
1375
73
1041.2
Goriano Sicoli
399975
4659721
785
51
838.9
Massa d'Albe
367195
4663229
856
46
793.6
Ortona dei M.
396164
4646886
948
13
920.0
Ortucchio
386976
4645391
680
27
719.6
Ovindoli
377507
4666466
1363
78
1088.1
Pescasseroli
399582
4629509
1150
49
1550.5
Pescina
389295
4653777
749
61
786.0
Rocca di Mezzo
378157
4673776
1329
51
996.2
Roccavivi
378517
4630136
479
74
1445.3
Rosciolo
362774
4664300
903
49
848.1
S. Benedetto dei M.
386830
4652119
687
49
618.0
Scanno
407375
4639749
1030
50
1086.8
Scurcola
362709
4658659
730
50
902.1
Villavallelonga
385229
4637028
945
80
1241.1
Table 17: Annual medium rainfall in Fucino Basin
52
Figure 36 – annual medium rainfall map in Fucino Basin.
Although this variability, all the monitoring gauges in the Fucino plain are characterized by a
continental climate, with the minimum rainfall in July and the maximum rainfall in November
(Figure 37.)
300
Prec. media mensile [mm
250
200
150
100
50
0
gen
feb
mar
apr
mag
giu
lug
ago
set
ott
nov
dic
Figure 37 – Monthly rainfall in 28 gauge of Fucino Basin
53
WATER-MAP Project
5.3.2 Temperature
In the same way used for rainfall analysis, all the temperature data have been analyzed to define the
minimum and medium value (Table 18).
Temperature data are available from 1921 until 2003: the minimum value is about -3°C (in January)
and the maximum value is about 27°C (in July) and the medium value is about 12°C.
In the Figure 38 are represented all the thermometric gauges (23 gauges) of Fucino Basin (13
gauges) and in his boundary (10m gauges).
Figure 38 –Temperature gauges in Fucino Basin.
54
years
Annual average
Temperature
[°C]
698
26
11.4
708
61
11.7
4630451
400
44
12.8
397060
4641999
1216
46
9.0
366725
4647532
735
44
11.1
384125
4658333
834
48
10.9
STAZIONE
Est_UTM33
Nord_UTM33
Avezzano (E. F.)
369188
4654952
Avezzano (S. I.)
369299
4655999
Balsorano (E. F.)
379954
Bisegna (E. F.)
Capistrello
Cerchio
elevation
[m asl]
Civita d'Antino
373148
4638405
893
13
11.2
Fucino 8000
379831
4650475
652
49
10.8
Gioia Vecchio
395066
4639560
1375
48
8.6
Goriano Sicoli
399975
4659721
785
49
11.8
Massa d'Albe
367195
4663229
856
41
10.6
Ortona dei M.
396164
4646886
948
10
9.4
Ortucchio
386976
4645391
680
24
10.6
Ovindoli
377507
4666466
1363
45
6.8
Pescasseroli
399582
4629509
1150
46
8.0
Rocca di Mezzo
378157
4673776
1329
49
7.9
Rosciolo
362774
4664300
903
44
11.5
S. Benedetto dei M.
386830
4652119
687
49
11.1
Scanno
407375
4639749
1030
46
10.0
Scurcola
362709
4658659
730
41
10.3
Villavallelonga
385229
4637028
945
48
10.4
Table 18 – Annual medium temperature in Fucino Basin.
55
WATER-MAP Project
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Figure 39 – Monthly temperature in Fucino Basin.
5.3.3 Potential evaporation – transpiration (PET)
The evaluation of potential evaporation-transpiration (PET) was realized using all the temperature
data: more specifically, the monthly value of this parameter was valued by the Thornthwait formula
(Figure 40).
56
Figure 40 – Annual mean value of potential evaporation - transpiration in Fucino basin.
5.4 Geological and Hydrogeological aspects
5.4.1 Geology
Fucino Basin is about 900 km2 large and is a part of Laziale-Abruzzese Apennines; his main
morphological characteristic is the wide plain (about 200 km2), bordered by carbonate mountains
(Figure 41).
The carbonate mountains show a high permeability due to fracturing and karstic effects and so they
constitute aquifers of high capacity. The carbonate aquifers bounded by pelitic impervious deposits
located in the uppermost portion of the plain and, in part, from the clastic deposits at the foot of the
mountainous slopes; these impervious strata allow the existence of important groups of springs but
also the leakage of groundwater from carbonate aquifers to the alluvial aquifers of the plain. The
Plain constitutes a hydro-geological unit, characterized by detritic and alluvial strata constituted by
gravel, sand and clay, whose permeability results extremely variable.
57
WATER-MAP Project
Fig. 4.1 - geological map of Fucino basin
Figure 41 – Geological cross - section of Fucino basin.
5.4.2 Hydrogeology
The Plain constitutes a hydrogeological unit, characterized by detritus and alluvial strata constituted
by gravel, sand and clay, whose permeability results extremely variable (Figure 42).
The carbonate mountains show a high permeability due to fracturing and karstic effects and so they
constitute aquifers of high capacity. The carbonate aquifers bounded by pelitic impervious deposits
located in the uppermost portion of the plain and, in part, from the clastic deposits at the foot of the
mountainous slopes; these impervious strata allow the existence of important groups of springs but
also the leakage of groundwater from carbonate aquifers to the alluvial aquifers of the plain.
58
Main springs are at the bottom of carbonate mountains, in prevalence at the south-eastern limit
(Trasacco, Ortucchio, Venere) and at the northern limit (Celano) of the plain.
Figure 42 - Hydrogeological scheme of Fucino Basin.
5.5 Piezometric surface
Piezometric surface presents a depth between 5-6 m (in the plain area) and more than 100 m
(surrounding the eastern limit of the Plain near Aielli, Cerchio and Celano municipalities) (Table
19).
The elevation of piezometric surface is included between 640 m asl and 715 m asl but, somewhere
the piezometric level is above the field level (artesian wells) (Figure 43).
59
WATER-MAP Project
Figure 43 –Piezometric map of Fucino Plain.
Est
Code Municipality
UTM33
A
B
C
D
E
F
Avezzano
Celano
Pescina
Ortucchio
Trasacco
Trasacco
373020
380036
388662
388380
377315
377669
Nord
UTM33
4654672
4655094
4652881
4647061
4647291
4649629
Field
elevation
(m asl)
662.00
653.40
713.00
661.00
656.60
653.00
well Piezometric Piezometric
depth table depth
level
notes
(m)
(m)
(m asl)
60
2.50
659.50 phreatic
102
-2.40
655.80 artesian
100
25.70
687.30 phreatic
105
-5.40
666.40 artesian
42
1.60
655.00 phreatic
100
2.20
650.80 phreatic
Table 19 – Piezometric values in some wells of Fucino Basin.
60
6 Hydrometeorological and Hydrogeological data of the Mean Sea Level
aquifer recharge area in the island of Malta5
6.1 Location-Description of the study-area
The Maltese Archipelago consists of three inhabited islands: Malta, Gozo and Comino, and a
number of uninhabited islets scattered around the shoreline of the major islands. The islands are
located at about 96km south of Sicily (Italy) and 290km north of Tunisia (between 35° 48’ and 36°
05’ N and 14° 11’ and 14° 35’ E). The total surface area is about 316km2 and the perimeter of the
shoreline of the island of Malta is 136km while that of Gozo is 43km.
The Water-Map Project will focus its studies on the Mean Sea Level Groundwater body in the
island of Malta. This Groundwater Body is by far the major groundwater body in the Maltese
islands and yields an estimated 66% of the total groundwater abstracted in the country. In fact an
estimated 23 million m3 of groundwater is abstracted annually from this groundwater body; thirteen
million of which are abstracted by the Water Services Corporation for potable purposes with the
remaining 10 million m3 being abstracted by private entities for a variety of uses including potable,
irrigation, industrial and tourism purposes. Under optimum conditions the MSL system is estimated
to store up to 1.5 billion m3 of groundwater.
6.1.1 Topographical and geographical location of the study area
The Malta Main Mean Sea Level Groundwater Body is sustained in the Lower Coralline Limestone
aquifer and is in free contact with sea-water. This groundwater body extends over the whole
southern and central parts of the island, under the Rabat-Dingli plateau (to the west), and the Mgarr
Plateau, the Wardija Ridge up to the Pwales Valley as its northern boundary, as is shown in Figure
44.
5
Chapter realised by Malta Resources Authority
61
WATER-MAP Project
MT001
Malta Main Mean Sea Level
Groundwater Body
Figure 44: Boundaries of the Malta Main Mean Sea Level Groundwater Body.
In real terms the groundwater body can be compared to a lens shaped body of fresh-water floating
on more saline water, having a convex piezometric surface and conversely a concave interface
sloping towards the land. The thickness of the lens below sea level is roughly thirty-six times its
piezometric height above sea level following closely the Ghyben-Herzberg model.
Its surface area, mostly overlain by Globigerina Limestone is 216.6km2. South of the Pwales
Valley, over a total area of 37.8km2 the Upper Coralline Limestone overlies the Lower Coralline
Limestone aquifer, but is separated from it by the more or less impervious Greensand and Blue Clay
formations.
6.2 Meteorological Data
The climate of the Maltese Islands is typically semi-arid Mediterranean, characterised by hot, dry
summers and mild, wet winters. During the summer season, the islands are dominated by highpressure conditions. The mean annual rainfall was about 550mm for the period 1900-2000 but with
high seasonal and interannual variability (variation coefficient: 27 percent), with some years being
excessively wet, and others being extremely dry. The highest precipitation rates generally occur
between October and February (Table 20). Rainfall is characterised by storms of high intensity but
of relatively short duration.
62
Month
Rainfall
Max. Temp.
(°C)
(mm)
January
Min Temp.
86.4
14.9
10.0
February
57.7
15.2
10.0
March
41.8
16.6
10.7
April
23.2
18.5
12.5
May
10.4
22.7
15.6
June
2.0
27.0
19.2
July
1.8
29.9
21.9
August
4.8
30.1
22.5
September
29.5
27.7
20.9
October
87.8
23.9
17.7
November
91.4
20.0
14.4
December
104.3
16.7
11.4
Table 20 Mean monthly values of main climate parameters, Malta
6.2.1 6.2.1 Rainfall
Figure 45 presents the annual rainfall for the Luqa meteorological station for the period 1947-2004.
The average rainfall for this site for this period was 569mm (Figure 45). In order to give a better
impression of the interannual variability, Figure 46 presents the deviation of annual rainfall from
the long-term average for the same meteorological station. This figure shows that annual rainfall of
300mm more or 250mm less that the average is common. Although there is no indication of
systematic variability, consecutive years of above- or below- average annual rainfall are common.
1000
900
800
700
600
500
400
300
200
100
2004
2001
1998
1995
1992
1989
1986
1983
1980
1977
1974
1971
1968
1965
1962
1959
1956
1953
1950
1947
0
Figure 45: Annual Rainfall for Luqa Meteorological Station (1947-2004).
63
WATER-MAP Project
In Malta and Gozo, the WSC operates 14 rain gauges, 3 weather stations, 3 wind monitoring
stations and 4 runoff recorders. From the data gathered by the WSC from its weather stations, the
highest maximum rainfall intensity was registered in 1994/95 with 56mm/hr; whilst the lowest
maximum intensity was 16.8mm/hr in 2000/01.
Figure 46 Deviation from mean annual rainfall for Luqa met. Station (1947-2004).
6.2.2 Temperature
During the hydrological year 2001/02, the WSC registered 108 days of rain with the maximum
rainfall intensity being 20.4mm/hr. The maximum wind speed was recorded at 24.5m/s. The
highest maximum and minimum temperatures were recorded as 37.1 and 3.2 °C, respectively, with
the average maximum temperature of 20.6 °C being the lowest registered in the most recent sevenyear period. The average evaporation, wind speed and mean rainfall were 5.4mm/day, 3.2m/s and
24mm/month, respectively.
6.2.3 Evapotranspiration
The potential evapotranspiration calculated by the Penman formula using 1947-1989 climatological
data for the Maltese islands is 1,390mm (albedo=0.2) with an interannual variability of 3 percent.
Table 21 summarizes various figures for annual average rainfall, actual evapotranspiration, runoff
and effective rainfall rates as calculated in different studies.
64
Rainfall
Evapotranspiration
Author
Runoff
Effective Rainfall
(mm)
Morris (1952)/Edelmann
(1968)
522
392
130
ATIGA (Martin)
587
475
95
ATIGA (Verhoeven/Gessel)
536
439
97
ATIGA (WWD Data)
551
431
120
FAO
587
437
150
Spiteri Staines (19870
508
356
BEGM (1991)
551
348
30
122
203
Table 21 Rainfall, evapotranspiration and effective rainfall.
Based on the models developed by the Bureau de Recherche Geologique et Miniere (BRGM, 1991),
preliminary estimates of actual evapotranspiration rates have been calculated on the basis of daily
rainfall values recorded at the Luqa Meteorological Office (1948-1998). These estimates indicated
that actual evapotranspiration varied between 197 and 402mm, or 36 – 89 percent of the measured
annual rainfall.
6.2.4 Runoff
Most runoff occurs after heavy torrential rain. This is the only time when surface water flows (for a
few days at most) along the beds of the major valleys. To retain this storm discharge, 31 small
dams have been constructed across the drainage lines. They also serve the purpose of reducing the
rate of soil erosion. Total dam capacity is estimated at 154,000m3. A number of open reservoirs
have been constructed along roads to catch flowing water; their total volume is estimated at
250,000m3.
The Rural Development Plan for Malta reports that in 1993 there were a total of 18 dam systems
with a total capacity of 37,000m3 that were no longer in use and notes that “this number is likely to
have increased since then” (Figure 47). However, the cleaning and rehabilitation of dam systems
has recently been recognized as an important aspect of water management. Major rehabilitation
works were undertaken in 1997 on the Wied il-Qlejjgha Dam systems, while rehabilitation and
upgrading works have been carried out in the last years on major dams in Malta including those of
the Wied il-Ghasel, Wied is-Sewda, Wied il-Kbir and Burmarrad valley systems.
According to Edelmann (1968), the eight-year average of surface runoff at the Marsa gauge which
controls a large part of the Wied il-Kbir and Wied is-Sewda catchments, ranged between 2 and 3
percent of the annual precipitation. The same study reports that at the Mannarino gauge, only 1
percent of the rainfall was registered. ATIGA (1972) assumed an average surface runoff of 3
percent of rainfall to take into consideration the distribution between inland rural and built up areas.
65
WATER-MAP Project
Runoff records for 1961-62 in the Burmarrad Valley basin, which lies north of the Victoria Fault,
gauged runoff at about 0.5 percent of the total rainfall.
Figure 47 Location of Dams in the main water courses in Malta.
In view of the lack of observational data to support these assumptions, the runoff from rural areas
that is lost to the sea is considered to be in the range of 2-5 percent of the annual rainfall. In urban
areas, localized runoff is considered to be as high as 80 percent of annual rainfall with the amount
lost to the sea being highly dependent on the geographical location.
Hence, land-use and
urbanization have a considerable impact on the hydrology and water balances of different parts of
the islands.
6.2.5 Infiltration
It is estimated that, over the long term, the part of rainfall that infiltrates into the underground and
recharges groundwater is about 32%, with variations from “wet” to “dry” years. In a wet year, up to
280 mm of rainfall (80 million m3) may recharge groundwater, while in a dry year the recharge may
be as low as 56 mm (16 million m3).
6.3 Geological Framework
The geology of the Maltese islands comprises a succession of Tertiary limestones and marls with
scarce Quaternary deposits. Essentially, the islands are geologically made up of a core of clays and
marls, the Blue Clay and the Globigerina Limestone formations stacked between two limestone
formations known as the Upper and the Lower Coralline Limestones. The oldest formation, the
66
Lower Coralline Limestone is of Oligocene Age whilst the Maltese succession ends in the Miocene,
with the top of the Upper Coralline Limestone being chronologically dated to the Upper Messinian
age possibly extending into the early Pliocene (Figure 48).
6.3.1 Geological description of the region
From a structural point of view, the Maltese islands can be subdivided into three regions, primarily
consisting of two elevated blocks separated by the two major NE-SW fault lines present in the
islands, namely the Ghajnsielem-Qala fault in the north and the Victoria fault in the south. Between
these two faults a structural graben stretching between southern Gozo, Comino and northern Malta
separates the two upthrown blocks.
In a significant part of the island of Malta, south of the Victoria fault-line, the Upper Coralline
Limestone and the Globigerina/Lower Coralline Limestone formations are stacked vertically. The
Lower Coralline Limestone in this region occurs mainly at sea-level and is thus in lateral and
vertical contact with sea-water. The Upper Coralline Limestone formation outcrops mainly on the
western side of the island, perched over the Blue Clay formation.
The downthrown region of the archipelago, north of the Victoria fault, is divided by a NE-SW fault
system into a succession of horst and graben like structures.
This structure with parallel
compartments separated by faults leads to the formation of relatively small aquifer blocks which are
independent from one another from a hydrogeological point of view.
In the island of Gozo, north of the Ghajnsielem-Qala Fault, the Lower Coralline Limestone occurs
at sea-level and is overlain by the Globigerina Limestone formation over much of the whole of the
island. The Upper Coralline Limestone outcrops over the peaks and on high-grounds, perched over
the impervious Blue Clay formation in the northern and central regions of the island.
67
WATER-MAP Project
Figure 48 Geological Map of the Maltese Islands.
The lithological different natures of these formations together with their geological position give
occurrence to two broad aquifer types:
the upper (perched) aquifers in the Upper Coralline
Limestone and the lower (mean sea level) aquifers in the lower limestone units (the Lower
Coralline Limestone, and where fractured in the Globigerina Limestone). Due to the depressed
structure of the central region of the archipelago, the Upper Coralline Limestone also hosts small
sea-level aquifers in the Northern region of Malta.
The Upper and Lower Coralline Limestones are thus considered to function as the main aquifer
formations in the islands. The Globigerina limestone functions only locally as an aquifer formation,
only where it is fractured and/or is located at sea-level, and is commonly expected to allow
groundwater flow exclusively through fractures and fissures. The Blue Clay and the Greensand
formations are normally impermeable and underlie the perched aquifers.
6.3.2 Stratigraphical Sequence
The Geological formations exposed in the Maltese islands are of the Tertiary and Quaternary Ages,
having been deposited in the last 35 million years (Figure 49). The Lower Coralline Limestone is
of the Oligocene Age(23-35 million years old); with the other overlying formations being of the
Miocene Age (5-23 million years old). The very top of the Upper Coralline Limestone could be of
the Upper Messinian Age possibly extending into the early Pliocene Age (1.6-5 million years old).
68
Figure 49: Schematic geological section.
The Upper Coralline Limestone (UCL) is a porous massive formation, which outcrops over the
western and northern zones of the island and forms the highest parts of the topography. In view of
its lithographic nature and its response to karstic erosion, this formation should be considered as a
porous and fissured formation that could contain a generalised aquifer. The UCL formation varies
considerably in thickness due to erosion. The existing thickness in the ridges and plateaus averages
30m, while the range in the valleys (structurally low blocks) is 60-90m with a 100m maximum
thickness being reached at Bingemma, south of the village of Mgarr. The rather small thickness of
this formation on the plateaus has historically made possible the direct exploitation of water
resources by shallow wells. The outcrops of the UCL act as a generalised recharge area for the
underlying groundwater body.
The Greensand (GS) formation occurs as green glauconitic marl and rusty-coloured, sandy textured
limestone. The thickness of this formation varies from 0.25 to 1.5m, locally increasing up to 12m.
The Blue Clay (BC) formation is considered as an aquitard that supports the groundwater body in
the UCL.
The karstic evolution that affected the Maltese Islands should have locally but
significantly modified this aquitard property, allowing groundwater stored in the UCL to ‘leak’
down to the underlying sea-level aquifer. The average thickness is about 30m, with the formation
generally being thicker in western Malta than in the east.
The Globigerina Limestone (GL) is generally a massive and porous formation, which is rather
homogeneous all over the Maltese Islands. Short regressive periods during its deposition have
69
WATER-MAP Project
created hardground and phosphoritic beds. Formations and also sedimentation conditions have
changed locally and resulted in thin clayey or marly layers interbedded in the GL formations.
These less-porous layers act as horizontal aquitards in the porous body of the GL, giving rise to
small local water tables in a perched position above the main water body. The total thickness of the
formation ranges from 30 to 210m.
The total thickness of the LCL formation is estimated at more than 450m according to
reconnaissance oil-well results. In the LCL, many coral-reef formations have developed under
shallow water and shoal conditions. The material of these reefal formations is generally more
porous than in the main part of this geological unit.
This observation is important from a
hydrogeological point of view as these reefs could be considered as higher permeability zones in the
porous matrix of the LCL. On the other hand the vertical and horizontal extensions of these reefs
are not known, nor are their volumes and their possible interconnections.
As such, the
hetereogeneity they create in the main aquifer body is important when assessing the general
hydrodynamic behaviour of the aquifer.
6.4 Hydrogeological Characterisation
6.4.1 Conceptual model of the groundwater body
The Lower Coralline Limestone aquifer is in lateral and vertical contact with seawater. Besides
differences in viscosity between the two fluids, there exists a density change which depends mainly
on salinity differences. In a stable system, freshwater floats on salt water and a landward sloping
interface separates them (Figure 50). Since the freshwater flow zone thickness decreases towards
the coast, the piezometric head or water table is convex and the interface is concave in a
homogeneous medium. The system therefore takes the shape of a freshwater lens floating on top of
saltwater with a thickness approximately 36 times more below sea level as compared to the
freshwater level above sea level.
Due to diffusion and hydrodynamic dispersion, the interface is really a mixing of transition zone the
thickness of which depends on the hydrodynamic characteristics of the aquifer. A sharp interface
between freshwater and sea water can only be assumed when this zone represents a few percent of
the freshwater thickness. The transition zone limits can be defined arbitrarily as the surfaces of 1
percent and 95 percent seawater content, based on total dissolved solids or chloride ion content.
The groundwater is not a rest, but flows away more or less horizontally. Part of this lateral flow is
recovered by public and private abstractions using galleries and boreholes, while the remaining part
continues its outward journey towards the coast, to be discharged into the surrounding sea.
Already, near the coast-line, the sea-ward flow of fresh ground-water comes into contact with sea
70
water. This sea water however is salt water with a higher specific gravity than freshwater. This
means that the pressure of sea water will increase more rapidly with depth than the pressure of
freshwater. Whatever the conditions at the surface may be, from a certain depth downwards the salt
water pressure tends to surpass the fresh water pressure, backing up this fresh water till again
equilibrium is obtained. In this way a fresh-salt water interface is formed, above which the impeded
outflow of freshwater takes place and below which salt water penetrates the aquifer over great
distances. Over a limited depth only do coastal aquifers carry fresh water, seriously limiting the
possibilities of freshwater abstraction.
Figure 50 Schematic representation of the freshwater lens.
6.4.2 Hydrogeological features
The Lower Coralline Limestone formation represents the most important aquifer rock in the
Maltese Islands, sustaining the major sea-level groundwater bodies which by far are the primary
sources of freshwater for the islands. It consists of an algal-foraminiferal limestone with solitary
corals, having a moderate, irregular and frequently layered or channel-like permeability.
In fact,
the high permeabilities of coral reefs are absent and are replaced instead by an irregular
permeability more characteristic of algal reefs. This heterogeneity is further accentuated by the
presence of scattered patch-reefs in lateral contact with lagoonal and forereef facies (Figure 51).
The primary porosity of the formation is highly variable and varies from 7 to 20%. The different
density shows that a large part of the primary porespace is not interconnected, which is also stressed
by the rather low primary permeabilities. Effective porosity in the rock porespace exists mainly in
connection with fracture permeability, otherwise the pores are very poorly interconnected. Flow
and dewatering of porespaces rely on secondary permeability by tectonical fracturing and solution
enlargement. The fractures range from microfissures to Karst solution caverns, and frequently the
fissuring is aligned in one direction. The main fracture trends in the Coralline Limestones follow
71
WATER-MAP Project
the fault trends SW-NE. Zones of fracturing are freeways for outflow to the sea, vertical intrusion
of sea water and direct downward flow of pollutants.
Secondary permeability is thus mainly fissure dependent and is estimated to range between 10 to
15% whilst the average hydraulic conductivity as measured from pumping tests is 400 x 10-6m/s.
The transmissivity of the formation is estimated to vary between 10-4 and 10-3m2/sec.
The Globigerina Limestone overlays the main aquifer over most of central and southern Malta.
Locally, the Globigerina Limestone where it is intensely fractured and located below the water table
becomes part of the Lower Coralline Limestone Aquifer. To the north of the Victoria Fault line the
Lower Coralline Limestone is locally depressed below sea level and overlain by the Blue Clays in
western Malta namely at the synclines of Mgarr, Bingemma and Falka. The primary porosity and
permeability of the massive formation are not effective for groundwater storage and release.
Figure 51 West-East section of Malta from Fawwara to Ricasoli, showing the Globigerina Limestone Formation
depressing below sea-level in the Hamrun syncline.
6.4.3 Groundwater Balance
Replenishment of the aquifers is by rainfall and leaks from the water supply system. Surface runoff
into the sea is comparatively small because of the morhphology, good water absorption by the soil
and infiltration into the rocks, and runoff interception by numerous dams, walls and terraces built
over the centuries. The major surface water loss is by evapotranspiration. Aquifer recharge varies
according to the rainfall. The amount of water in storage in the Ghyben-Herzberg lens of the main
aquifer is of the order of 1,500 billion m3. Before the impacts of groundwater overabstraction, this
could be considered quite large compared with yearly recharge, whereas the recharge forms a very
large percentage of the water in storage in the perched and coastal aquifers. In the sea-level
aquifers, the yearly recharge replaces abstraction and storage water after dry years.
In relative
terms, a considerable amount of water flows into the sea from coastal and submarine springs or is
lost by diffusion into the sea. As the existence of the freshwater lens also implies an outflow
gradient, even in years of sub-normal rainfall, freshwater is lost in this way, and this adds to the
72
water deficiency in the sea level aquifers. The occurrence of this outflow is a pre-requisite for the
existence of the freshwater lens.
Exploitation of the sea-level groundwater body started during 1856 when a shaft was sunk at LArmier, at the inner edge of Marsa. From 1885 onwards this was steadily increased with the
construction of a number of pumping stations skimming the surface of the groundwater body.
During the 1970's groundwater production from the Lower Coralline Limestone aquifer was
boosted through the implementation of an intensive borehole drilling campaign.
Overall
groundwater production figures increased but with a corresponding deleterious effect on the
qualitative status of the aquifers. In fact by 1980 the average weighted annual salinity of the water
abstracted from the mean sea level groundwater body had shot up to 1600mg/l, exactly twice what
it was in 1969. By then, it had become evident that the heavily depleted aquifers could no longer
meet the growing water demand and Reverse Osmosis technology was chosen as the strategic
alternative water supply for the islands. As a result total groundwater abstraction for public
purposes has been reduced by over 25%. However, this change has been accompanied by an
increase in abstraction by the agricultural sector for irrigation purposes which has partially offset
the expected recovery in groundwater status.
GW-Body
Code
Size
Name
2
Km
Recharge
3
hm
Extraction
3
hm
Malta (Main)
MT001
Mean Sea Level
Major
Balance
Extraction
hm3
Potable
216.6
34.27
36.05
Agriculture
-2.37
Table 22 Simplified water balance for the groundwater body.
A balance of groundwater reserves in the sea-level groundwater body has been computed for the
period 2003-04, and presented in Table 22. Results indicated that the total abstraction from the
Lower Coralline limestone aquifer was of the same order, if not exceeding, the recharge. Several
data-gaps constrain the accuracy of water balance estimations while making some computations
impossible.
The quality of groundwater in Malta is highly variable with contamination of groundwater by nitrates and by chlorides
being the main quality issues of concern (Figure 52).
73
WATER-MAP Project
Figure 52 Nitrate content of groundwater abstracted from the LCL and UCL aquifers
Nitrates occur naturally in the environment and are produced from natural decay of vegetable material in the soil. The
natural nitrate level in the Mean Sea Level aquifer is generally expected to be low. Soil cover in Malta is relatively thin
and poor in organic content. Furthermore there are no naturally occurring formations that contribute towards nitrate
content in groundwater. Nitrate contamination in groundwater is thus largely attributed to anthropogenic activities
including: agricultural practices through the application of nitrogenous fertilizers on arable land and contamination from
human or animal wastes and refuse dump run-off. The movement of these pollutants below the surface is affected by
the properties of the underlying strata.
Nitrate concentration varies seasonally and by location, with maximum
concentrations corresponding to the rainy season (October-March) due to leaching of nitrates in the unsaturated zone.
Responses are more direct in the perched aquifers due to the karstic nature of the Upper Coralline Limestone than in the
sea-level aquifers where changes are more subdued.
74
Figure 53 Chloride content of groundwater abstracted from the LCL and UCL aquifers
Groundwater in Malta has generally high levels of chloride concentrations as a result of over-abstraction of
groundwater and seawater intrusion (Figure 53).
The situation is further influenced by the large perimeter in
comparison to the islands’ area and the karstic nature of the aquifer. Generally chloride levels in the perched aquifer are
significantly lower that the mean sea level aquifer and these lower values result from the topographical nature where the
aquifer is largely protected from sea water intrusion. However relatively higher chloride concentrations at Bingemma
and Mizieb pumping stations occasionally have been registered and these are attributed to periods of increased
abstraction and influenced by seawater intrusion since the top of the confining clay layer lies below the mean sea level.
75
WATER-MAP Project
6.6 6.6
References
ATIGA Consortium (1972) Wastes disposal and water supply project in Malta, United Nations
Development Programme
Axiaq V. & Sammut A.(2002)
The Coast and Freshwater Resources. In: State of the
Environment, Report for Malta 2002, Ministry for Home Affairs and the Environment, August
2002.
Blue Plan, 2000
Indicators for the Sustainable Development in the Mediterranean Region.
Sophia Antipolis, France.
Borg S. 2004 Review and critical assessment of the legal framework for groundwater in Malta
FAO/MRA Consultancy Report
BRGM (1991)
Study of the fresh-water resources of Malta, Government of Malta
Costain, R. (1955)
Geological Investigations in the Maltese Islands
Department of Agriculture
Soil data from MALSIS Project
Edelmann 1968
The Conservation of Runoff Water FAO Consultancy Report
Falkland A. (Ed)
(1991).
Hydrology and water resources of small islands: a practical guide. UNESCO
FAO. 1997. Seawater intrusion in coastal aquifers: Guidelines for study, monitoring and control.
FAO Water Report 11. Rome.
Lang D.M. 1960,
Soils of Malta and Gozo Colonial Research Studies No 29, Colonial Office.
Malta Environment and Planning Authority Mapserver
Malta Environment and Planning Authority GIS and Mapping Data
Malta Resources Authority The Annual Report 2001-2004
Malta Resources Authority (2005) Initial Characterisation of the Groundwater Bodies within the
Maltese Water Catchment District under the Water Policy Framework Regulations, 2004.
Mangion J. et al (2004)
The Oligocene Limestone Aquifers of Malta and Gozo,
BaSeLiNe Project EVK1-2002-00527
Morris T.O. (1952)
EU
The Water Supply Resources of Malta, Government of Malta
Sammut A. (2003) Case Study - Malta: Present conditions of water resources and major patters
of water use in Malta, Proceedings in the SUSTAINIS Workshop EVK1 - CT-2002-60001
76
Sapiano M. 2004
Review of the water resources of the Maltese Islands
Consultancy Report
Vella S. (2000)
Soil information in the Maltese Islands
FAO/MRA
Options Mediterraneennes.
Water Services Corporation The Annual Report 1997-2004
Water Services Corporation Hydroclimatological Data 1994-2004
Water Services Corporation (2004) Strategic Plan 2004-2008
77
WATER-MAP Project
7 Hydrometeorological and Hydrogeological data of Mouriki basin,
Kozani prefecture, Western Macedonia region, Greece
Mouriki basin (Figure 54 e Figure 55Figure 2) is located in the north part of Kozani Prefecture
(Municipalities Mouriki and Ptolemais), Western Macedonia region, Greece.
Ptolemaida
Basin
Mouriki
Basin
Figure 54: Topographic map of the study area.
78
Figure 55: Topographic map and sheaded view of the study area.
It is a sub-basin of Ptolemaida Basin which covers an area of 2.145 km2. Five other sub-basins,
Ptolemaidas, Sarigiol, Begoritidas, Xeimaditidas and Petron, are also included in the total
Ptolemaida Basin.
Mouriki Basin covers an area of 133.6 km2 (Figure 54). The mean altitude of the basin is about 875
m asl and the mean slope 26.1% (Table 23).
79
WATER-MAP Project
Area (km2)
Mean slope (%)
133.6
875.0
26.1
Table 23: General characteristics of the Mouriki basin.
Municipal
compartments
Population
Municipal
compartments
Population
Emporio
1003
Galateia
530
Anaraxi
1150
Olympias
693
Miloxori
743
Varikon
698
Foufas
857
Drosero
327
Table 24: Villages of Mouriki Basin
Figure 56: Mouriki Basin
80
Mouriki Basin is oriented from the west side from Mouriki Mountain, and the following Villages
(Table 24) are located in it:
The flat area which covers 33.0% of the total basin is intensively cultivated agriculture. The main
cultivations are wheat (10%), maze (60%), apple trees (20%) and vegetables (10%). Also cattle and
sheep breading activities are met around and in the basin.
The area is characterized by a semi-arid, Mediterranean climate, with an annual temperature of
approximately 11.3 °C and an annual rainfall of 413.3 mm (1980-2001) (Table 25). About 70-80% of
annual rainfall occurs in wet period, while summers are usually dry.
413.3
11.3
9-39
Mean annual rainfall (mm)
Mean annual temperature (oC)
Mean annual discharge (x106 m3/y)
Table 25: Summary statistics of meteorological data in alluvial aquifer of Mouriki basin.
7.2.1 Rainfall and Temperature
The flat area of Mouriki basin, with mean altitude equal to 665 m asl, is closed to gauging gauge of
Ptolemaida (650 m asl) so the data of Ptolemaida gauge can be considered representative (Table 26;
Figure 57: Mean monthly rainfall (mm) fluctuation at Ptolemaida gauge.,Figure 57, Figure 58).
January
February
March
April
May
June
July
August
September
October
November
December
RAINFALL
(mm)
25.7
27.2
27.2
39.1
48.3
29.4
28.9
21.6
21.0
45.8
59.7
39.5
TEMPERATURE
(oC)
1.2
2.3
6.0
9.8
14.7
19.5
22.1
21.5
17.5
12.3
6.3
2.5
Total
413.4
Average
34.5
11.3
ΜΙΝ
21.0
1.2
ΜΑΧ
59.7
22.1
Table 26: Rainfall and Temperature data of Ptolemaida gauging gauge (1980-2001).
81
WATER-MAP Project
1980-2001
70
60
Rainfall (mm)
50
40
30
20
10
be
r
N
ov
em
be
D
r
ec
em
be
r
ct
o
O
te
m
be
r
us
t
Au
g
Se
p
Ju
ly
Ju
ne
ay
M
il
Ap
r
ar
ch
M
ry
ua
Fe
br
Ja
n
ua
r
y
0
Figure 57: Mean monthly rainfall (mm) fluctuation at Ptolemaida gauge.
Rainfall depth is correlated strongly with the altitude. The relationship between the annual rainfall (P)
and the elevation (H) was estimated by using the Thiesen method (data from 7 rain gauging gauges of
the wider area).
The relationship between the annual rainfall and the elevation is explained by the regression line:
P (mm)=0.61 H (m) + 86.4
Thus, the mean annual rainfall increases by 61mm per 100 m of ground elevation.
According to temperature data from three different measurement gauges the correlation between
elevation and average, maximum and minimum temperature were estimated. Table 27 gives the
used data.
The correlation between elevation and temperature are:
Average max temperature: a(max) = 4.4oC/km
Average min temperature: a(min) = 5.6 oC/km
Average temperature:
A/A
Gauge Name
1
a(average) = 4.7 oC/km
Altitude
Average Annual
o
Average Max Annual
Average Min Annual
o
(m)
Temperature ( C)
Temperature ( C)
Temperature (oC)
Amyntaio
578.3
12.6
18.3
6.8
2
Limnoxori
600.3
12.6
18.3
7.0
3
Ptolemaida
650.0
11.3
17.6
4.9
Table 27: Meteorological data of three measurement gauges
82
Because of the large differences among them it is decided that the average annual correlation will
be taken account in all the calculations. These correlations are for the Total Ptolemaida Basin.
7.2.2 Evaportranspiration
The evaportranspiration was calculated for the gauge of Ptolemaida by using the Thornthwaite
Method (
Table 28). Temperature and rainfall data of a representative year (1998) were used .
The annual evapotranspiration for the Ptolemaida gauge is 412.1 mm.
83
WATER-MAP Project
1980-2001
25
0
Temperature ( C)
20
15
10
5
r
r
em
be
em
be
D
ec
N
ov
ct
O
m
be
te
ob
er
r
t
us
ly
Se
p
Au
g
Ju
Ju
M
ne
ay
il
Ap
r
ar
ch
M
ry
ua
Fe
br
Ja
nu
ar
y
0
Figure 58: Mean monthly temperature (0C) fluctuation at Ptolemaida gauge.
1980-2001
70
25
60
20
15
T (0C)
40
30
RAINFALL (mm)
TEMPERATURE (oC)
10
20
5
10
Au
gu
Se
st
pt
em
be
r
O
ct
ob
er
No
ve
m
De be
r
ce
m
be
r
Ju
ly
Ju
ne
M
ay
0
Ap
ril
0
Ja
nu
a
Fe ry
br
ua
ry
M
ar
ch
P (mm)
50
Figure 59: Mean monthly rainfall (mm) and temperature (0C) fluctuation at Ptolemaida gauge.
84
Evapotranspiration by Τhornthwaite
Ws =
110
α=
1.300
Coefficient of actual
evapotranspiration
79.3%
J
F
M
A
M
J
J
A
S
O
N
D
1.60
0.18
1.40
0.15
6.30
1.42
11.3
3.44
16.1
5.87
20.2
8.28
21.3
8.97
22.4
9.68
17.5
6.66
14.1
4.80
6.7
1.56
2.1
0.27
3.5
3.0
20.9
44.7
70.8
95.0
101.8
108.7
78.9
59.6
22.6
5.0
N
Ep’
(mm)
0.84
0.83
1.03
1.11
1.24
1.25
1.27
1.18
1.04
0.96
0.83
0.81
3.0
2.5
21.5
49.6
87.8
118.8
129.3
128.3
82.0
57.2
18.8
4.1
702.73
P (mm)
53.4
30.6
48
40.2
14.2
104.4
22.3
21.7
22.4
30.1
97.9
34.5
519.7
Deficit
0.0
0.0
0.0
9.4
73.6
14.4
107.0
106.6
59.6
27.1
0.0
0.0
Surplus
50.4
28.1
26.5
0.0
0.0
0.0
0.0
0.0
0.0
79.1
30.4
APWL
0.0
0.0
0.0
-9.4
-82.9
-97.3
-204.3
-310.9
-370.5
0.0
397.6
0.0
0.0
St
110.0
110.0
110.0
101.0
51.8
45.4
17.2
6.5
3.8
3.0
82.1
110.0
ΔSt
0.0
0.0
0.0
-9.0
-49.3
-6.3
-28.2
-10.6
-2.7
-0.8
79.1
27.9
Er
3.0
2.5
21.5
49.2
63.5
110.7
50.5
32.3
25.1
30.9
18.8
4.1
412.1
Q
50.4
28.1
26.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
2.5
107.6
T (0C)
i
Ep
(mm)
Mean/Total
11.75
51.28
Table 28: Estimated water balance at Ptolemaida gauge, using Thornthwaite-Mather method.
T=temperature, i=heat index, Ep=potential evapotranspiration, N=factor depending on latitude, Ep′= corrected potential evapotranspiration, P= rainfall,
APWL=accumulated potential water loss, Ws=maximum water storage in the soil, ΔWs=Wsi-Wsi-1, Er=actual evapotranspiration ,
Q=surface runoff + infiltration
12
T=the monthly temperature (oC) and I=the annual heat index: I= ∑ i j
1
ij=the monthly heat index of the month j; ij=(T/5)
1.514
a= 0.49239 + (1792x10-5) I –(771x10-7) I2 + (675 x 10-9) I3
85
WATER-MAP Project
7.2.3 Runoff
The Mouriki basin’s surface discharge is made by Potamia stream. According to measures (realized
by IGME) from 4 hydrologic years (1982-1986) the annual discharge varies from 9 - 39 x106 m3.
The mountainous area of Mouriki basin is covered by the Crystalline basement, the semi
mountainous area is covered by Neogene and Pleistocene deposits and the flat area where we will
apply the Drastic method is covered by alluvial deposits.
Figure 60: Stratigraphic sequence in Ptolemaida basin (adapted from IGME).
86
PLEISTOCANE
HOLOCENE
Crystalline
basement
NEOGENE
Figure 61: Geological structure of Mouriki basin.
87
WATER-MAP Project
7.4 Hydrogeology
7.4.1 Hydrogeological characterisation
The main aquifer system is developed in alluvial deposits (alluvial aquifer) located above Neogene
deposits.
The water needs of the basin are predominantly being covered by the exploitation of alluvial
aquifer, through a large number of boreholes (approximately 250). The potable water demand for
the villages situated in Mouriki is covered by springs of crystalline schists and karstic spring.
The alluvial deposits cover an area of 33 km2 with mean altitude 665m approximately.
The depth of alluvial aquifer reaches 160 m below ground surface (b.g.s.). The alluvial deposits
host a phreatic aquifer superimposed on successive confined or semi-confined aquifers. There is
hydraulic connection between them due to their “lens” form, as well as with the phreatic aquifer.
Despite the documented heterogeneities however, it is suggested that on a regional scale a uniform
aquifer may be considered.
88
Sand - Clay
Sand
Clay
Shingle
Clay
Grit
Shingle
Clay
Gravel with Sand
Clay
Gravel with Sand
Clay
Sand
Clay
Figure 62: Typical lithology section of drill at Mouriki basin
89
WATER-MAP Project
7.4.2 Piezometric surface
The depth to water table in the alluvial aquifer ranges from 0 to 15 m (wet period) and 1 to 43.5m
(dry period) below ground surface or from +624 to +737 m asl and +593.5 to 736 m asl above sea
level (O.Patrikaki, Phd preparation).
High piezometric levels are recorded in the SW part of the aquifer and low piezometric levels are
recorded in NE part.
Groundwater flows are mainly from the South-West toward North-East, as deduced from
piezometric maps (Figure 63).
Figure 63: Piezometric map of the alluvial aquifer in Mouriki basin for period May 2004 (Patrikaki, PhD in preparation).
90
7.4.3 Hydraulic parameters
One pumping test analysis was realized in the frame of Water Map project and a second one was
realized by IGME (Stamou, 2006). According to these pumping test analyses the hydraulic
properties of the alluvial aquifer system range as shown at the following Table 29. The realized
pumping tests sites are shown at the Figure 64.
Figure 64: Sites of realized pumping tests
Storage coefficient
Hydraulic conductivity (k)
(m /min)
(S)
(m/min)
1
9.06x10-2 - 9.99x10-2
3.54x10-3 - 2.66x10-3
1.51x10-3 - 1.66x10-3
2
8.88x10-2 - 8.93x10-2
4.52x10-2 - 4.35x10-2
1.5x10-3 - 1.51x10-3
Transmissivity (T)
2
Table 29: Hydraulic parameters of the alluvial aquifer of Mouriki basin.
91
WATER-MAP Project
According to water analyses realized in Mouriki basin (O.Patrikaki, PHd preparation), the
groundwater is not polluted from nitrite (the concentration is lower than the limit for the legislation
potable water) although intensive cultivation is taking place in the basin. Exception are two specific
areas of the basin at the East part (Drosero village) and West part (Foufas village) where the nitrite
concentration of water coming from shallow (<30m) drills is very high.
7.6 Soil Quality
A research realized by IGME at 2001 was determined the type of soils and general soil
characteristics (Table 30), the concentrations of micronutrients (Table 31) and the concentrations of
the main elements at Mouriki basin. The soil samples were taken at depth of 30cm.
Also soil samples were collected from Environmental Centre at the framework of Water Map
project at May of 2007 from soil at Mouriki basin from depth of 30cm, 50 cm and 70 cm but the
results are not yet available.
SAMPLE
CLAY %
SILT %
SAND%
SOIL TYPE
789
6.8
16.29
76.91
790
5.75
10.17
84.05
791
21.03
42.08
36.89
792
8.81
19.55
71.63
793
20.29
18.97
60.75
794
16.58
25.53
57.89
795
10.53
50.64
38.83
796
21.92
50.93
27.15
797
2.92
20.43
76.65
loam sand
loam sand
loam
sandy loam
sandy clay loam
sandy loam
silt loam
silt loam
loam sand
loam sand
loam
loam sand
loam sand
sandy loam
loam
loam
798
6.69
14.53
78.78
809
12.03
37.26
50.72
811
6.26
11.7
82.04
812
3.12
13.79
83.09
813
10.7
32.58
56.72
814
21.95
32.97
45.07
815
14.73
42.02
43.25
Specific el.
conductivity
(μS/cm)
pH
CEC
meq/100gr
ORG.
MATTER
CaCO3 %
228
7.83
15.97
1.43
33.57
180
8.05
19.52
0.82
0.31
213
7.55
37.27
1.87
1.83
193
8.1
15.97
1.09
23.75
234
6.34
24.84
1.91
0.025
235
7.92
35.49
1.67
0.76
416
7.5
30.17
2.87
3.08
349
7.35
35.48
2.18
11.65
185
8.2
15.97
0.88
9.19
184
7.5
14.19
1.02
30.53
559
7.6
28.39
3.69
21.07
196
7.16
17.74
1.02
0.025
230
7.78
14.19
1.19
1.29
263
7.8
21.29
3.241
64.24
400
7.8
26.62
3.691
63.92
380
7.74
37.27
9.901
77.85
Table 30: Determination of soil type and general characteristics of soil at Mouriki basin.
92
SAMPLE
789
790
791
792
793
794
795
796
797
798
809
810
811
812
813
814
815
Cu(1)
20
18
26
25
18
19
24
28
22
37
27
17
12
19
26
15
8
Pb(2)
10
9
20
12
16
17
15
17
9
9
26
17
9
9
21
16
12
Zn(1)
20
28
67
26
43
42
61
74
26
23
44
49
24
23
56
34
12
Co(1)
8
19
20
9
15
21
15
16
11
6
10
13
14
12
6
5
3
Ni(2)
76
260
120
98
56
230
81
95
114
67
105
138
163
153
32
32
12
Cr(2)
50
150
90
70
60
140
60
80
80
40
60
70
100
90
30
30
20
Mo(5)
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
Cd(1)
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
As(1)
1
2
3
1
2
2
3
3
2
1
2
4
2
2
2
2
1
Sb(0.1)
<0.1
<0.1
3
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
V(10)
12
38
40
21
36
47
40
39
18
14
22
31
28
27
20
14
12
Cs(1)
2
2
2
2
2
1
2
1
2
2
3
1
1
1
3
3
3
Table 31: Chemical analysis of micronutrients (ppm) at Mouriki basin and their limits (ppm) from methodology (AAS).
SAMPLE
789
790
791
792
793
794
795
796
797
798
809
810
811
812
813
814
815
LOI
19.2
4.1
9.5
14.2
5.7
7.1
8.7
12.9
7.4
16.5
18.2
21.5
3.4
4.21
34
34.5
47.3
SiO2
46
72.5
59
54.5
68
69
58
50.5
67.5
51
49.5
44.5
75.5
76
18.5
18.5
5.2
TiO2
0.2
0.4
0.5
0.3
0.4
0.4
0.6
0.6
0.3
0.2
0.2
0.3
0.4
0.3
0.2
0.2
0.05
Al2O3
5.5
8.6
13.7
6.7
12.8
10.1
14
13.7
7.9
6.5
6.1
6
8.3
7.6
5.2
4.8
1.4
FeO3
2.1
4.5
6
2.7
4.8
4.7
5.4
6.2
3.1
2.4
2.9
2.9
3.5
3
1.9
2
0.6
CaO
21.6
2.8
3.7
15.4
2.5
2.6
5
8.2
6.8
19
15.1
12.8
2
2.7
37.3
37.2
42.5
MgO
1.5
2.7
2
1.7
0.8
1.7
1.9
3
1.9
1.4
4.2
8.8
1.7
1.9
0.7
0.9
1.2
K2O
1
1.3
1.9
1.4
1.9
1.8
2.1
2.1
1.7
1.2
0.1
0.9
1.6
1.4
0.8
0.7
0.2
Na2O
1.2
1.4
1.8
1.4
2
1.5
2.3
1.5
1.6
1.2
0.9
0.8
1.6
1.5
0.3
0.4
0.1
MnO
0.12
0.12
0.13
0.12
0.15
0.12
0.17
0.15
0.12
0.14
0.13
0.14
0.15
0.15
0.1
0.1
0.1
P2O5
0.1
0.06
0.11
0.09
0.05
0.05
0.17
0.12
0.05
0.12
0.18
0.15
0.04
0.07
0.3
0.2
0.07
Table 32: Chemical analysis of main elements (%) of soil at Mouriki basin
93
WATER-MAP Project
7.7 References
− Institute of Geological and Mineral Exploration (IGME), 2001. “Chemical -Pedologic study
of Kozani -Ptolemaida- Amyntaio”.
− Ministry of Development, Administration of Natural Resources- Department of aqua
dynamic and natural resources, 2006. “Planning management of natural resources of water
districts of Western Macedonia, Central Macedonia, Eastern Macedonia and Thrace”.
− Patrikaki O., 2007. “Hydrogeological conditions in Perdika basin – Ptolemais”. (PhD in
preparation).
−
Stamou A., 2001. “Hydrogeological studies for development and rational management of
water resources of Western Macedonia”. Institute of Geological and Mineral Exploration
(IGME).
94

WATER-MAP Project

Transcription

Similar documents

Awesome Aquifers - Groundwater Foundation

Presentation: VCWWD#1 Moorpark Desalter Project Update

Building Code Training – August 30th at Burgundy Basin Inn

Rainwater harvesting for Aquifer Storage and Recovery

Puzzle it out - Anglian Water

HAZTURK Için Istanbul`da Deprem Sonrasi Yersel Ivme Dagiliminin

Basin Spring Park - Eureka Springs History

WMO Task Force on Social and Economic Applications of Public

Hydrocarbon Opportunities in Peru