Impacts and threats to
groundwater
Deliverable D1.1
Partner: Joanneum Research Forschungsgesellschaft mbH
H. Kupfersberger
2
Deliverable summary
Project title
Acronym
Date due
Final version submitted to EC
Complete references
Contact person
Contact information
Authors and their affiliation
Project homepage
Confidentiality
Key words
Summary (publishable) for
policy uptake
Groundwater and Dependent Ecosystems: New Scientific and
Technological Basis for Assessing Climate Change and Land-use
Impacts on Groundwater
GENESIS
Contract number 226536
Month 10 in GENESIS
Month 10 in GENESIS
Hans Kupfersberger
Joanneum Research, Institute for Water, Energy and Sustainability,
Elisabethstr. 18, A-8010 Graz, Austria,
[email protected]
Hans Kupfersberger (JR)
www.thegenesisproject.eu
Public
groundwater systems, land use impacts, Groundwater Directive,
GENESIS test sites
Groundwater systems in Europe significantly differ with respect to
their geological settings, climate conditions, size, land-uses and water
utilization. In order to review the present situation on European scale,
17 test sites from 15 different countries have been evaluated.
Conflicts of interest may arise between various groundwater uses and
users that result in a wide range of impacts on aquifer systems.
Within this report, impacts and threats are described in detail on (i)
groundwater dynamics, recharge and water balance of groundwater
systems, (ii) substances leaching to groundwater aquifers due to
different land-uses and (iii) groundwater dependent ecosystems
interacting with surface water.
These results will be input for the working packages where research
on processes in groundwater systems and their mathematical
implementation in models is conducted. Additionally, likely future
scenarios of groundwater systems use can be deduced from the test
sites which will lead to the development of economical and social
viable measures for groundwater protection. In this context, the
national River Basin Management Plans have also been analyzed.
Finally, possible gaps with respect to the WFD and the GWD
encountered at the test sites are discussed and a general overview of
modeling approaches used is compiled.
3
List of GENESIS partners
Norwegian Institute for Agricultural and Environmental Research (CO)
Bioforsk
Norway
University of Oulu
UOULU
Finland
Joanneum Research Forschungsgesellschaft mbH
JR
Austria
Swiss Federal Institute of Technology Zurich
ETH
Switzerland
Luleå University of Technology
LUT
Sweden
University of Bucharest
UB
Romania
GIS-Geoindustry, s.r.o.
GIS
Chezk Repulic
French National institute for Agricultural research
INRA
France
Alterra - Wageningen University and Research Centre
Alterra
The Netherlands
Helmholtz München Gesundheit Umwelt
HMGU
Germany
Swiss Federal Institute of Aquatic Science and Technology
EAWAG
Switzerland
University of Science and Technology
AGH
Poland
Università Cattolica del Sacro Cuore
UCSC
Italy
Integrated Global Ecosystem Management Research and Consulting Co.
IGEM
Turkey
Technical University of Valencia
UPVLC
Spain
Democritus University of Thrace
DUTh
Greece
Cracow University of Technology
CUT
Poland
University of Neuchâtel
UNINE
Switzerland
University of Ferrara
UNIFE
Italy
Athens University of Economics and Business- Research Centre
AUEB-RC
Greece
University of Dundee
UNIVDUN
United Kingdom
University of Zagreb - Faculty of Mining, Geology and Petroleum
Engineering
UNIZG-RGNF
Croatia
Helmholtz Centre for Environmental Research
UFZ
Germany
Swedish Meteorological and Hydrological Institute
SMHI
Sweden
University of Manchester
UNIMAN
United Kingdom
4
Table of contents
1.
Overview of impacts and threats to typical GWs and GDEs within the Genesis test sites
....................................................................................................... 9
1.1. Impacts and threats on groundwater dynamics, recharge and water balance of
groundwater systems .............................................................................. 20
1.1.1. Grue site, Norway ....................................................................... 21
1.1.2. Rokua site, Finland ...................................................................... 21
1.1.3. Murtal aquifer, Austria.................................................................. 21
1.1.4. Zagreb site, Croatia ..................................................................... 22
1.1.5. Vosvozis site, Greece ................................................................... 22
1.1.6. Mancha Oriental site, Spain ............................................................ 22
1.1.7. Areuse site, Switzerland ................................................................ 23
1.1.8. De Kromme Rijn site, The Netherlands............................................... 23
1.2. Impacts and threats on substances leaching to groundwater aquifers due to different
land-uses ............................................................................................. 24
1.2.1. Grue site, Norway ....................................................................... 25
1.2.2. Koycegiz-Dalyan (KD) site, Turkey .................................................... 26
1.2.3. Caretti site, Italy ........................................................................ 26
1.2.4. Feucherolles site, France............................................................... 26
1.2.5. Murtal site, Austria ...................................................................... 27
1.2.6. Zagreb site, Croatia ..................................................................... 27
1.2.7. Vosvozis site, Greece ................................................................... 27
1.2.8. Mancha Oriental site, Spain ............................................................ 28
1.2.9. Areuse site, Switzerland ................................................................ 28
1.2.10. Czestochowa site, Poland ............................................................. 28
1.2.11. Bitterfeld site, Germany .............................................................. 29
1.2.12. Po valley site, Italy .................................................................... 30
1.2.13. De Kromme Rijn site, The Netherlands ............................................. 30
5
1.3. Impacts and threats on groundwater dependent ecosystems interacting with surface
water …… ............................. ………………………………………………………………………………...31
1.3.1. Grue site, Norway ....................................................................... 32
1.3.2. Rokua site, Finland ...................................................................... 32
1.3.3. Koycegiz-Dalyan (KD) site, Turkey .................................................... 32
1.3.4. Vosvozis site, Greece ................................................................... 33
1.3.5. Sumava site, Czech Republic .......................................................... 33
1.3.6. Czestochowa site, Poland .............................................................. 34
1.3.7. Bogucice site, Poland ................................................................... 34
1.3.8. Lule site, Sweden ........................................................................ 34
1.3.9. Po valley site, Italy ...................................................................... 35
1.3.10. De Kromme Rijn site, The Netherlands ............................................. 35
1.4.
Possible gaps with the WFD and/or GWD .............................................. 36
1.4.1. Grue site, Norway ....................................................................... 37
1.4.2. Rokua site, Finland ...................................................................... 37
1.4.3. Koycegiz-Dalyan (KD) site, Turkey .................................................... 37
1.4.4. Caretti site, Italy ........................................................................ 37
1.4.5. Zagreb site, Croatia ..................................................................... 38
1.4.6. Vosvozis site, Greece ................................................................... 38
1.4.7. Areuse site, Switzerland ................................................................ 38
1.4.8. De Kromme Rijn site, The Netherlands............................................... 38
1.5.
2.
Impacts and threats on groundwater systems and River Basin Management Plans39
A general overview of modeling approaches used and their purposes ................... 41
2.1.
Grue site, Norway ......................................................................... 43
2.2.
Caretti site, Italy .......................................................................... 43
2.3.
Murtal aquifer, Austria .................................................................... 44
2.4.
Feucherolles site, France ................................................................. 44
2.5.
Zagreb site, Croatia ....................................................................... 45
6
2.6.
Vosvozis site, Greece ..................................................................... 45
2.7.
Mancha Oriental site, Spain .............................................................. 46
2.8.
Bogucice site, Poland ..................................................................... 47
2.9.
Lule site, Sweden .......................................................................... 48
2.10. Po valley site, Italy ........................................................................ 48
2.11. De Kromme Rijn site, The Netherlands ................................................. 48
7
Groundwater systems in Europe significantly differ with respect to their geological settings, climate
conditions, size, land-uses and water utilization. In order to review the present situation and measures
on European scale, 17 test cases from 15 different countries have been evaluated. The areas include the
Mediterranean zone, Central and Western Europe as well as Scandinavia; hydrogeological regimes range
from lagoon systems, fractured rock, sand and gravel aquifers and karst systems to peatlands and
eskers.
Typically, conflicts of interest may arise between various groundwater uses and users, e.g. drinking
water supply, agriculture, hydropower generation or groundwater dependent ecosystems. Additionally,
groundwater use results in a wide range of impacts on the aquifer systems like altering groundwater
dynamics and balance or worsening groundwater quality due to leaching of substances.
Based on the analysis of case studies of groundwater systems and groundwater dependent ecosystems
the most relevant and actual impacts and threats shall be revealed. These results will be input for
further working packages where research on processes in groundwater systems and their mathematical
implementation in models is conducted. Furthermore, likely future scenarios of groundwater systems
use can be deduced from the test sites considering all relevant stakeholders which will lead to the
development of economical and social viable measures for groundwater protection (WP6). The basis will
be provided for model development testing and scenario simulations to generate new tools and
improved insight for updates of the WFD and GWD.
Within this report, first, an overview about geological settings, climate, hydrology and land-use of the
different test sites is given. Then, impacts and threats are described in detail

on groundwater dynamics, recharge and water balance of groundwater systems,

on substances leaching to groundwater aquifers due to different land-uses and

on groundwater dependent ecosystems interacting with surface water.
Moreover, possible gaps with respect to the WFD and the GWD are discussed. Finally, a general
overview of modeling approaches used and their purposes with a specific focus on model requirements
and data availability and needs is put together.
The site characteristics presented here are based on information provided by the corresponding project
partners. The work package leader is responsible for making selection thereof, interpretation and
summary (at the beginning of each chapter) of the facts.
8
1. Overview of impacts and threats to typical GWs and GDEs
within the Genesis test sites
Because of interdependencies and to better understand the impacts and threats to groundwater
systems a short introduction to the geological setting, the climate conditions, the hydrology and the
current land-use that prevail at each test site is given as a basis. In order to restrict the report to a
reasonable extent and to avoid replication of unspecific information only excerpts of the information
provided from the partners responsible of the test sites is presented. The locations of the sites are
shown in figure 3 of the DoW on a European scale.
Overview of geological settings, climate, hydrology and land-use at the Grue site, Norway
The area is situated above a deep basin filled with marine deposits beneath a top layer of fluvial
sediments. Clay has been found at a depth of 13-15 m in several drill holes. Above this level the deposits
consists mainly of sand with a top layer of flood plain sediments of coarse silt and sand. The thickness of
the unsaturated zone normally ranges between 1.8 and 6 m.
Average annual temperature and precipitation in this area is 3.3 ˚C and 635 mm, respectively. The mean
groundwater recharge is estimated to be at a size of 300 mm/year.
Precipitation normally falls as snow in December–March with snowmelt in April. During winter the soil is
frozen. The pattern of groundwater recharge has a seasonal cycle with minima in summer and winter
and maxima in spring due to infiltration of water from snowmelt.
The flow pattern of the aquifer is characterised by groundwater flow towards the river most of the year.
Only during flood peaks in spring and autumn water will flow into the aquifer from the river Glomma.
Overview of geological settings, climate, hydrology and land-use at the Rokua site, Finland
The Rokua esker (area 70 km2) is located in Northern Finland, in the region of Northern Ostrobothnia. It
is a part of a chain of esker ridges stretching from the island of Hailuoto in Gulf of Bothnia to Ilomantsi in
eastern Finland.
Rokua is a large glaciflucial deposit with the highest point rising 80 meters above the surrounding
wetland areas (200 meters above sea level). The esker consists mainly of sandy soils. During its
formation in the last glaciation, the glaciers and meltwaters loosened homogenous material from easily
crumbling and weathered surface bedrock, which were deposited in Rokua. Small “kettle” lakes are
situated within the esker area. Most of these lakes have no outlet or inlet: the water level is dependent
of the ground water level of the esker.
9
The climate is cold with snow cover lasting throughout the winter until late April. The average
precipitation in the area is 500-600 mm and 30-50 % of precipitation is estimated to recharge the
groundwater. The annual average temperature is 2.0 degrees Celsius.
The Rokua esker sandy recharge areas remain in quite natural state. In the lowland discharge areas
intensive peatland drainage mainly for forestry, but to some extent also for agriculture and peat
harvesting has been carried out since 1940’s. Small amounts of the Rokua groundwater (100 – 200 m3/d)
is used as drinking water by the residents and in the Rokua Spa and health center. The regulated lake
Oulu is located at one end of the esker.
Overview of geological settings, climate, hydrology and land-use at the Caretti site, Italy
The site is located in the Po plain (Pianura Padana), immediately to the east of the historical centre of
the city of Ferrara. The size of the contaminated area at the moment is estimated 0.026 km2, the areal
size of the entire multi-layered aquifer system (of regional extension) is about 11,164 km2.
The general conceptual model of the Po plain is that one of a multi-aquifer system, made of porous
sandy aquifers and clayey-silty aquitards. The main aquifer in this area is the deeper 1st confined
regional aquifer (A1-I), composed by medium-fine grained sand of 20 m average thickness. The aquifer
A1-I is locally separated at the top by a 6 m thick clayey aquitard from the above A01 aquifer. Even if at
the site scale A1-I is separated by A01, it is still to be defined if there are connections between the two
aquifers on a broader area at the regional scale. The hydraulic conductivity is in the range of 1-8×10-4
m/s and the hydraulic gradient corresponds to 0.4-1 ‰. Recharge of the aquifer A1-I occurs by leakage
through the confining layer and by lateral recharge from the Po river, which is in contact with the sandy
aquifer 8 km to the north.
Using the data of a meteorological station from 1990 to 1998, the average rainfall in Ferrara results in
about 700 mm/year, with a mean temperature of 13°C.
One of the main Italian petrochemical plants is located very close to the city of Ferrara. The plant has
produced, among various compounds, Poli Vinyl Chloride (PVC), starting from VC monomer (from 1953
to 1998) and halomethanes (since 1951 to 1984). Groundwater contaminations by chlorinated
hydrocarbons were detected not only in subsurface of the plant area, but also in at least 3 urbanized
sites in the city surroundings. Considering that some of the contaminated sites are located up
groundwater gradient of the plant, the chlorinated hydrocarbons could have originated from the plant
itself via illegal waste disposal at locations surrounding the site.
During the 1950’s excavation of clay pits started to derive raw materials for brick production. Since the
1960’s the pits were used as waste disposals. Urbanization of the surrounding area started and grew
progressively until the beginning of the 1990’s. Surface dumps remnants vanished below a vegetated
cover. Between 2000 and 2003, the discovery of the contamination halted the development of new
10
residential areas. As a consequence, since 2004 the municipality of Ferrara took over the responsibility
of the site characterization of the whole area defined as the Caretti site.
Contamination at Caretti site probably affects also the confined aquifer used as the main groundwater
source of Ferrara province. By the way, the nearest well field plant is not affected by contamination,
because located quite far away (8 km) and up gradient to contamination source and because the aquifer
is always recharged by the Po River. Nearby the site, groundwater of the first confined aquifer is not
used for drinking purposes; irrigation wells are present but they do not show evidence of contamination.
Overview of geological settings, climate, hydrology and land-use at the Murtal aquifer, Austria
The quarternary valley floor of the river Mur downstream the alpine area to the Slovenian border covers
an area of more than 300 km². The groundwater system is built up by an unconfined shallow stream
aquifer with a thin soil cover. The quaternary fluvial-glacial sediments typically show high hydraulic
conductivities. In the floodplain area Eutric to dystric Fluvisol including sandy alluvial sediments
dominate, whereas at the terraces Dystric Cambisol (siliceous; loamy-sandy) can be found. The riverine
zone mostly is covered by riparian forests.
Due to the topographic situation the intensive use of the sub-alpine basins results into conflicts of
interests between the ever-increasing use of the resource land and water. Agricultural production of
high yield crops as well as agricultural biomass production is increasing resulting into high nitrate
concentrations in groundwater for the last and future decades. The average precipitation, groundwater
recharge and temperature in the study area is 750 mm, 350 mm and about 11°, respectively, which can
be summarized in general as a moderate alpine foothills climate.
Overview of geological settings, climate, hydrology and land-use at the Feucherolles site, France
Located 50 km west of Paris a field experiment started in 1998 to study the long-term effects of
repeated applications of urban waste composts. The site is located on the plateau of Alluets Le Roi
(48°53’ N; 1°58’ E). Developed on quaternary loess deposits, the soil is a silt loam Glossic Luvisol and is
representative of loamy soils of Paris Basin regional area. The size of the field site is 6 ha whereas the
total area of the plateau is about 180 km2. On the field experiment, the soil is conventionally cropped
with a biannual rotation winter wheat-maize, two major crops of the region.
The geological stratification of the plateau of Alluets-le-Roi is typical of the Parisian Basin. A 2-m layer of
loess covers a buhrstone clay bed called “Argiles à Meulières” that crowns the sands and sandstones of
the Oligocene “Sables de Fontainebleau” formation (50 to 60 m depth) which constitutes the main
aquifer of the region. The main use is for drinking water supply. The aquifer recharge has a mean value
estimated to 80 mm/year y. Climatic data are currently measured on site since 2002 and climatic series
are available in the vicinity at a daily frequency (since 1971).
11
The clay bed constitutes a discontinuous aquitard on which a temporary perched water table may be
formed. A recent piezometric study on the experimental site has shown that the temporary perched
water table flows out laterally to draining windows or channels located within the clay bed. These zones
of preferential infiltration are mainly located in small topographical depressions and have an important
contribution to the recharge of the underlying sand aquifer.
Overview of geological settings, climate, hydrology and land-use at the Köyceğiz Dalyan (KD) site, Turkey
KD case study region is in semi humid class under the influence of Mediterranean climate
characteristics, with a hot, dry summer season and a warm, rainy winter season. January is the coldest
month with an average temperature of 9.2°C, July is the warmest month with an average temperature
of 28.8°C and the annual average temperature is 18.3°C in the site. Long term average annual
precipitation was found to be around 1083 mm. Long term average annual evaporation was found to be
around 1200 mm. A decreasing trend for precipitation and evaporation between 1985 and 2000 is
observed.
The KD case study area has a relatively heterogeneous geological structure and geomorphology at the
two sites of Dalyan channel. The watershed itself is considered as a tectonic depression zone. There are
alluvial and karstic regions. There are several geologically interesting features such as hot and cold water
springs, springs that contain high amount of salinity and hydrogen sulphide. Lime-free brown soil, which
is characterized by high clay content and sometimes stony clay texture with pebbles, is the dominant
soil type in the area. The second major type of soil, the Mediterranean red-brown soil composed of hard
limestone, granite, and rocks, is typically in dry climate conditions. Alluvial soil types have thicker soil
cover whereas red-brown and brown soils are too shallow. Lime is mostly observed on alluvial and
hydromorphologic soils.
Main source of potable water in the site is groundwater. There are 3 deep wells to supply water to
Dalyan town with 200 m3/h production capacity. Both surface water and groundwater are used for
irrigation in the area. An irrigation channel from Akköprü reservoir on Dalaman river reaches to the site
and serves to farmers. Annualy safety pumping amount of water for Okçular-Dalyan Village Plain was
estimated as 14x106 m3/year.
70% of total area is covered with natural vegetation that contains forest, scrub and frigana vegetations.
Agricultural activitiy is 25% of the total land use and common in Dalyan Town side of case study area.
Nitrogen loads that reach the aquatic ecosystem were calculated as 9.2 tons N/year from point sources
and 61.5 tonsN /year from non-point sources. Similarly, phosphorus loads were calculated as 1.37 tons
P/year from point sources and 5.14 tons P/year from non-point sources.
12
Overview of geological settings, climate, hydrology and land-use at the Zagreb site, Croatia
The Zagreb aquifer system is located in the NW part of the Republic of Croatia, along the Sava River. It
covers an area of approximately 350 km2 and is the only and therefore exceptionally important source of
potable water for the Croatian capital.
The aquifer system is built of two Quaternary aquifers which can be divided into three basic units:
aquifer system overburden built of clay and silt; shallow Holocene aquifer built of medium-grain gravel
mixed with sands; and deeper aquifers from Middle and Upper Pleistocene, with frequent lateral and
vertical alterations of gravel, sand and clay. The average seasonal resources are estimated to be at the
size of the 105 × 106 m3/year. Average annual temperature and precipitation are 11.7°C and 920 mm,
respectively. Thus, this area represents aquifers in temperate climate.
The Sava river, which is the main source of groundwater recharge within aquifer system, is in direct
hydraulic connection with the shallow aquifer, which has extremely high values of hydraulic conductivity
(up to 3000 m/day). The right bank of the Sava River is dominated by the intensive agriculture, even
near the largest well field in this area. Numerous well fields are accommodated within this aquifer
system.
Overview of geological settings, climate, hydrology and land-use at the Vosvozis site, Greece
Vosvozis catchment area covers an area of 340 km². The river’s length is 40 km. Vosvozis river discharges
into Ismarida lake. In the coastal part of the study area a system of coastal lagoons is formed, where
surface, groundwater and seawater interact. All the area of Ismarida lake and the coastal lagoons forms
an extremely important ecosystem.
From the geological-hydrogeological point of view, the upper part of study area, i.e. the part from the
Bulgrarian borders down to the mountain feet, is formed by Palaeozoic crystalline rocks of the Rhodope
massif, mainly consisting of gneisses, marbles and amphibolites. The plain area is formed by tertiary
sediments (molasic and alluvial deposits), mainly consisting of intercalations of permeable and less
permeable layers. The permeable formations consist of fine to medium grained sands and gravels,
whereas the less permeable formations consist of silts and clays. The total thickness of those sediments
is estimated to range from 50 to 500 meters, based on borehole data.
The climate is characterized as Mediterranean with dry hot summers and mild winters. The average
annual precipitation is approximately 650mm, whereas the average annual temperature is 15ºC. The
average groundwater recharge is estimated approximately 120mm/yr.
In those sedimentary formations two important aquifer systems are found. The first one is located close
to Komotini city. The total daily discharge pumped from the Komotini wellfield reaches 23,000 m3/d
providing domestic water to almost 70,000 inhabitants of the Komotini city and the surrounding
13
settlements. Groundwater pumping is taking place mainly during summertime, whereas during the rest
of the year Vosvozis river is used directly for domestic consumption, and when its water is of
appropriate quality (suspended load). The origin of the water extracted from the aquifer in the Komotini
wellfield is the nearby Vosvozis river, rain infiltrated directly into the aquifer, and lateral inflows from
the northern mountains.
The second major aquifer system is known as the Sidirohori aquifer, located on the southern part of the
study area, where water for irrigation use is abstracted from. This aquifer is important as it interacts
both with Vosvozis river as well as with Ismarida lake and the wetland area
Overview of geological settings, climate, hydrology and land-use at the Mancha Oriental site, Spain
La Mancha Oriental aquifer system (Hydrogeologic System 08.29) is located at the South-East of Spain,
on the eastern side of La Mancha plains (Castilla-La-Mancha region), extends over 7,260 km2 within the
Jucar river basin district, and contains one of the largest carbonate aquifers in Spain. The aquifer has as
its natural drainage the Jucar River in the stretch between two reservoirs (Alarcon and Molinar), of
about 80 km. The region has a mild Mediterranean climate, with dry summers and precipitations in
spring and autumn. Semi-arid and with extreme cold winters (under 6°C) and hot summers (above 24°C),
the average annual temperatures vary between 13°C and 14.5°C. Precipitation varies between 350 mm
in the south and 550 in the north. The average groundwater recharge is estimated to 165 mm/year.
The hydrogeological system can be considered as a multilayer aquifer, composed by 9 hydrogeological
units from which only 3 can be considered as aquifers. The first one is from the Jurassic period, and it is
mostly a confined aquifer constituted by dolomites and highly karstified limestone with a thickness of
250-500 meters and transmissivites between 2400 and 12000 m²/day. The Cretaceous aquifer behaves
as unconfined in the north and confined in the rest; its thickness is between 50-150 meters and its
transmissivites are lower than in the Jurassic aquifer. The Miocene aquifer is the most exploited one,
and it behaves as an unconfined aquifer with transmissivites of about 480-8400 m2/day. There is a
hydraulic connection between them, which can be vertical or lateral, depending on the sector. The
Miocene aquifer is hydraulically connected to the Jucar river; the river is gaining in some reaches and
losing in others. A 3D groundwater flow model is available.
The aquifer supplies water for the irrigation of about 70,000 ha., provided with modern irrigation
techniques (mainly sprinklers and centre pivot systems), and for urban consumption to a population of
over 275,000 inhabitants. The annual water draft is about 400 Mm3 for irrigation and 25 Mm3 for urban
supply.
14
Overview of geological settings, climate, hydrology and land-use at the Areuse site, Switzerland
The study area is localised in the Northwest part of the Canton de Neuchâtel (Switzerland) near the
French borderline. The total Areuse catchment area covers an area of 407 km2. The Areuse river’s length
is 46 km.
The upper Jurassic limestone (320 to 350 m of thickness) makes up the aquifer. These fissured
limestones overlay an Argovian marls-limestone complex, considered as relatively impervious and hence
acting as a regional aquiclude. In the central part of synclines, a porous aquifer is located, partially
disconnected from the karstic aquifer, consisting of Cretaceous deposits (marls and sandstone). The
Taillères Lake is based in these deposits. The Areuse spring, also called “La Doux” spring (750 m) is the
major outflow from the basin.
Average annual temperature and precipitation in this area are 5°C and 1500 mm, respectively.
Precipitation normally falls as snow in December - March with snowmelt in April. A large part of
groundwater recharges originates from snow, which can strongly influence seasonality and duration of
flood events. The spring presents high variations of its discharge along the year: the maximum, the
minimum and the annual mean are respectively 53.5 m3/s, 270 l/s and 4.86 m3/s for the 1959-2009
period.
Areuse catchment area is representative of rural conditions. It is covered by forest (about 36%)
composed by oaks, firs and spruces and by meadows (about 64%) used for pasture and rearing.
Urbanization is limited (~2500 inhabitants corresponding to 20 people/km2) to villages in this
mountainous area because of harsh climatic conditions. The karst groundwater resource is used as
drinking water. Some pumping wells are located within the karst aquifer. In the dry summer of 2003,
water shortage occurred for some communities and as a reaction the communities switched to an
alternative water source. A number of pumping wells are located in the alluvial aquifer downgradient of
the spring, which indirectly depend on the discharge from the spring. The river Areuse that is fed by the
Areuse spring is used for hydroelectrical production.
Overview of geological settings, climate, hydrology and land-use at the Czestochowa site, Poland
The Czestochowa case site (area 2365 km2) lies in the southern part of Poland. The borders of the case
site correspond to the borders of the Main Groundwater Basin MGWB 326. The MGWB 326 aquifer is
naturally divided by the Warta river into two subbasins: (i) MGWB 326 (S) with documented disposable
water resources of 4,220 m3/h on the area of 170 km2, (ii) MGWB 326 (N) with documented disposable
water resources of 8,900 m3/h on the area of 570 km2. The area of the case site is shared by two main
Polish river basins: part of it lies within the basin of the Warta River – the main right-hand tribuatry of
the Odra River while the other part belongs to the Pilica river basin – the left tributary of the Vistula
catchment. Rivers often change their character from gaining (70% of the total flow from groundwater)
15
to draining even within short sections which together with a fracture – karstic geological structure (high
seepage) make groundwater flow conditions complex and vulnerable to hydrological conditions.
Average yearly precipitation varies between 600 and 800 mm/year. The climate is continental with low
humidity and relatively high seasonal amplitudes of temperature; the average yearly temperature is 70C.
The industrial activities of the Czestochowa town include textile, metallurgical, iron, steel, paper and
food processing. Urban areas and villages cover ca. 20% of the surface. The remaining part is mainly
agriculture and forestry.
Groundwater is the only resource of water for the Czestochowa region. At present 99% of inhabitants is
connected to the local water supply system based on 4 main groundwater intakes . The total water
consumption is 163 Mm³/year (2006). For the late 90s of the XX century considerable decrease of water
consumption in the domestic sector has been observed – water consumption dropped by 20%. The
average water use in the region of Czestochowa now is 169 l/day/capita.
Overview of geological settings, climate, hydrology and land-use at the Boguice site, Poland
The aquifer is located in the south of Poland. It covers the area of ca. 200 km2 and belongs to the
category of medium groundwater basins in Poland. The hydrogeology of the aquifer can be considered
in three areas: the recharge area related the outcrops of the Bogucice Sands in the south, the central
confined area generally with artesian water, and the northern discharge area in the Vistula river valley.
The effective base of the aquifer is the top of the clay and claystone of the Chodenice Beds. The
groundwater movement takes place from the outcrops in the south, in the direction of the Vistula river
valley where the aquifer is drained by upward seepage through semipermeable clayey formations of the
Tertiary Grabowiec Beds. Intensive exploitation decreased the water table in some localities causing
downward seepage. The upper, shallow aquifer located in Pleistocene-holocene sediments is related to
drainage system of Vistula river and its tributaries. Unsaturated zone consists mainly of sands and loess
of variable depth, from 0 in wetland areas to approximately 30 meters in the recharge area of deeper
aquifer layers. Soils are Cambisols developed on loess and clays in hilly areas, Podzols and Luvisols
developed on sands and Fluvisols developed in river valleys.
The climate has intermediate character between oceanic and continental. The yearly average
precipitation in the area is 725 mm, evapotranspiration 480mm and runoff 245mm. The recharge of the
groundwater is on the level of 8 to 28 percent of the precipitation. The annual average temperature is
8.2 degrees Celsius. Globally, urban areas and villages cover ca. 20% of the surface. The remaining part is
mainly agriculture (60%) and forestry (20%). In the eastern part of the area, forests and wetlands
dominate. The principal economic role of the deeper aquifer is to provide potable water for public and
private users. Estimated disposable resources of the MGWB 451 are 40,000 m3/d with typical well
capacities of 4 to 200 m3/h. Hospitals and food processing plants also exploit some wells. The yield of
16
the aquifer is insufficient to meet all the needs and, as a consequence, licensing conflicts arise between
water supply companies and industry on the amount of water available for safe exploitation.
Overview of geological settings, climate, hydrology and land-use at the Lule site, Sweden
Luleå river is historically a highly regulated water body with 15 river dams on it. Regulation is closely
related to hydropower production which is the major application of it. The biggest reservoirs are located
in the upstream part of the river. Case study site is situated in the middle stream of Luleå river. Kalix
river has its basin to the NE from Luleå river and remains the last large pristine river in Europe. Both sites
are located about 100-120 km from the river mouth.
Quaternary sediments in both areas built very complex picture. There are sediments of different type
and genesis. This makes identification of similar conditions in both pristine and regulated rivers more
complicated. Major area of the two presented case studies is covered with glacial and postglacial
depositions. Moraine is the dominating type of sediments. Areas surrounding the rivers are covered by
coarse grained sand, gravel and clay in Luleå case study, and fluvioglacial sediments with interlaying of
sand and clays in Kalix case study.
The climate in this area is subarctic, with monthly average temperature ranging from -15oC in January to
+14oC in July. Luleå river freezes in December, and remains frozen until April. About 45% of the
precipitation comes in the form of snow, and accumulates during winter until snowmelt in May. Rainfall
decreases gradually from the mountains towards the Gulf of Bothnia, averaging from 1000-1500
mm/year down to 400-700 mm/year, respectively. Evapotranspiration rate is very low. Effective
precipitation is around 300-350 mm/year in the coastal area. This portion of water mainly recharges
groundwater in the vicinity.
Overview of geological settings, climate, hydrology and land-use at the Bitterfeld site, Germany
The Bitterfeld region is located in the southeast of Saxony-Anhalt, Germany, and has a history of about
one hundred years of extensive mining and chemical industry. An area of about 235 km2 is affected in
the Bitterfeld region, of which an area of 25 km2 shows a significant groundwater contamination,
containing a volume of about 200 million m3.
The contaminated area of Bitterfeld is located in the floodplain of the Mulde River. The upper aquifer
consists of Quaternary sands and gravels. The Quaternary unit can be divided into a lower part,
represented by lower terrace sediments of the Weichselian Mulde and overlying sediments, composed
of braided river deposits of a smaller tributary stream. Both are separated by a hydraulically effective
clay layer. This aquifer is in parts underlain by the upper oligocene lignite seam acting as a local
aquitard. The lignite seam has been intensively mined in the southern part of Bitterfeld. The base of this
17
hydrogeological section is represented by middle Oligocene clays (Rupelian clay). The latter unit is
considered to be the regional scale aquitard, hence corresponding to the base of the groundwater
pollution.
Among the different tasks of land reclamation and restoration of pre-mining groundwater conditions,
the management of hazardous-waste deposits and groundwater remediation are the most urgent.
Underground and open-cast mining activities since 1830 led to an extensive lowering of the
groundwater table and a change of the groundwater dynamics. The consequences of the currently rising
groundwater level are not only damages to buildings, but also the mobilizing effect on contaminants and
their transport into basements of inhabited structures (buildings, houses). In the northwest of Bitterfeld,
several former opencast lignite mines have been used as landfills for chemical wastes. Since the
industrial dumps were incompletely sealed and are in contact with the groundwater, the contaminants
affected the groundwater directly. The landfills currently show a stagnating emission pattern.
The concentrations reach several hundreds of mg/l, exceeding effluent standards by several orders of
magnitude. Conventional ‘‘pump and treat’’ technologies are economically unfeasible in the long term,
due to the fact of the continuous output from the landfills and the necessary volumes of about 4 million
m³ per year.
Overview of geological settings, climate, hydrology and land-use at the Po valley, Italy
The size of the study is about 12500 km2. The extension is about 3 degrees of longitude (8°30’E 11°30’E), and 1 degree of latitude (44°50’N - 45°50’N). The regional authorities assessed 834 “fontanili”
springs which are semi-natural lowland springs. The infiltrated water coming down from Alps tends to
rise up from soil in a strip located in the flat area between Alps and river Po. Monks in the middle age
drilled wells is this strip and they put pipes 5-10 m deep for increasing the soil depth above ground
water table. Water rising up from soil by the pipes creates small ponds and canals. In the study 3
fontanili are monitored.
The general conceptual model of the Po plain is that of a multi-aquifer system, made of porous sandy
aquifers and clayey-silty aquitards. The alluvial nature of the deposits explains the stratigraphic
complexity of the site. For modelling proposes, the agricultural development regional survey (ERSAF)
divided the regional flat area into 14 homogeneous zones. The temperature in the region increase from
North to South and from West to East, the annual average is between 12 and 13 °C. Rainfall increases
from South to North and from East to West. The range of annual rainfall in the study area is between
600 and 1200 mm.
The main uses in the study area are not irrigated arable land (63% of the study area), rice fields (9%) and
urbanised (16%). At the present the trend show a reduction of agricultural uses with and a rise of urban
uses (6.2% within 1990-2000). Rice crop is present in the Eastern and Western part of the region. Near
18
Milano monks realised “Marcite” system: springs were canalised allowing grass growth also during
winter by thermal irrigation. Groundwater in this region is used as drinking and as irrigation water.
Overview of geological settings, climate, hydrology and land-use at the Kromme Rijn site, The
Netherlands
The catchment of the Langbroekerwetering area, located in the province of Utrecht, comprises a
network of artificial channels, of which the main channel of the network, the Langbroekerwetering, is
about 135 km long. The water levels in the entire channel system are controlled by a series of hydraulic
structures. The channel width is about 6—10 m. The depth is about 8 – 10 m and the mean discharge
increases from about 20 m3/s to about 32 m3/s over a stretch of 2.8 km. The Doorn waste water
treatment plant has a mean discharge of 4 m3 s-1 (1992—1993), flowing into the Langbroekerwetering
via a 24 km long ditch system, which is in addition to diffuse sources from agriculture a major source of
nutrients in the study area.
The annual precipitation between 1971 and 2000 amounts to ca. 800 mm/a and the precipitation
surplus is estimated at 270 mm/a. The mean annual temperature is about 10 oC.
The hydrogeological scheme of the subsoil can be subdivided into low conductive layers (clayey and
loamy material) and relatively high conductive aquifers (sandy and gravel-like material) due to fluvial
sedimentation by the river Rhine before the building of dams. Human induced drift sands became
common on the Utrechtse Heuvelrug. Only after artificial fertiliser became widely available in the
second part of the 19th century, the Utrechtse Heuvelrug was reforested. Nowadays, most of the push
moraines are covered with forest, both coniferous and deciduous.
The groundwater flow South of the Utrecht Ridge is directed westward to the Kromme Rijn. At the
Utrecht Ridge precipitation water infiltrates through the well-drained sand layers. Part of the infiltrated
water exfiltrates at the foot of the Utrecht Ridge, at the transition between the high and lower sandy
soils. Another section follows a longer path through the deep subsurface, in the first or second aquifer,
and may locally seep upward in more westerly areas. The seepage influence is truncated by the
presence of the Amsterdam-Rhine canal that makes a deep incision into the sandy aquifers. Also in
terms of the landscape the canal is a formidable barrier.
19
1.1. Impacts and threats on groundwater dynamics, recharge and
water balance of groundwater systems
Three major reasons can be identified that significantly influence groundwater recharge and the water
balance of groundwater systems. The most obvious cause of all is overexploitation, typically for the use
as agricultural irrigation. At the Greek site the observed drawdown between the starting of the pumping
period in May and the end in September reaches 20m. In Spain a maximum depletion of 100 m of
groundwater levels has been reached in 30 years of exploitation. As a consequence, flow patterns of
hydraulically connected surface water reservoirs become affected. At the Greek site the groundwater
level decline induces recharge from Vosvozis River and Ismarida lake (which was not the case before),
diminishing thus an important source for the wetland system. Another threat is the intrusion of
seawater in the wetland area (which is also relevant at the Turkish lagoon site). In Spain the streamflow
of the Jucar River becomes depleted. Thus, direct effects for groundwater dependent ecosystems are
related to groundwater overpumping.
The next reason deals with more general kinds of land use like gravel mining activities, increased sealing
of ground surfaces due to urbanisation and industrialization and artificial groundwater recharge
(washing sites, drinking water purpose) which all disturb natural conditions. An important component
within this group is the regulation of rivers that interact with groundwater which may lead to riverbed
erosion (potentially changing a feeding into a gaining river), the reduction of areal recharge from
flooding due to embankments and the prevention of any water exchange due to the colmation of water
reservoirs that were built for hydro power generation. A special case is the drainage of peatlands in
Finland which results into an easier decline of groundwater levels in eskers. Increased drainage (e.g.
installation of subsurface drains) has also contributed to the hydrological degradation in the
Netherlands.
Finally, climate change and with it the modification (or reduction) of seasonal water availability will
influence groundwater dynamics and the water balance of groundwater systems. Especially in mountain
regions small temperature variations will define the rainfall, snowfall and snowmelt. In the Swiss karst
aquifer with no buffer capacity some pumping wells were abandoned after the dry summer of 2003,
because their yield became insufficient. In addition, during the dry autumn 2009, the spring discharge
(and hence the river discharge) was too low for hydroelectrical production and likely had also some
affect on the river ecosystem. Furthermore, climate change may lead to increased agricultural irrigation.
In detail the following characteristics on groundwater dynamics, recharge and water balance of
groundwater systems are encountered at the respective case study sites.
20
1.1.1. Grue site, Norway
Within the Grue study area, about half of the local households get their drinking water from local
groundwater wells. In very dry years, some groundwater are also be used for irrigation of potatoes in
parts of the area.
At present, the current local use of groundwater does not cause severe impacts or threats on dynamics,
recharge and water balance of the groundwater system in the case study area. However, locally altered
flow patters around wells and areas with artificially increased recharge, e.g. washing sites, might be
important for the local patterns of spreading of contaminants.
Climatic changes may lead to increased agricultural irrigation and altered land use. Both river water and
groundwater might be used for irrigation, and the effects of increased irrigation on the aquifer
hydrology will differ dependent on the choice of sources water.
Although several hydropower plants exists within the catchment of river Glomma, the degree of runoff
regulation is low in Glomma, and hydropower regulation is thus have minor importance for the
hydrology of the case study aquifer.
1.1.2. Rokua site, Finland
A key hypothesis is that peatland drainage has resulted in changes ingroundwater dynamics. As the
water is more easily drained from the esker, less groundwater gradient is required to maintain the
natural outflow and hence the groundwater levels can have been reduced. To some extent the recharge
can have been changed with climate or varied naturally. Also more intense construction of roads and
housing might have changed runoff patterns to some extent. However, the site remains quite in natural
state.
1.1.3. Murtal aquifer, Austria
Gravel mining activities change the land surface and influence groundwater quantity and quality.
Increasing urbanisation and industrialization leads to different groundwater recharge and higher water
demand. Resulting groundwater level changes, as well as surface water flooding influence the
ecosystem. Due to the restoration of natural dynamics of particular river sections flooding of the
riverine area will change in areal extent and time. Additionally, artificial groundwater recharge using
different sources of water is implemented. In general this type of groundwater shows an extreme
vulnerability to climate change.
21
1.1.4. Zagreb site, Croatia
The Sava river represents the main source of water for the Zagreb aquifer system. Although recharge
also occurs through precipitation, the changes in the Sava river elevations dominantly influence the
changes in the groundwater levels across the whole aquifer. Quantity of ground water is diminishing
continuously due to negative trends of ground water levels. The main reasons for lowering of
groundwater levels are (1) embankment of the Sava river which stopped occasional flooding of the area
and potential infiltration to groundwater; (2) extensive riverbed erosion due to upstream Sava river
regulation; (3) excessive pumping at the municipal and industrial well fields; and (4) prolonged drought
periods. Ground water levels have already reached the minimum levels (top elevation of the well
screens) on some well fields, causing water scarcity during droughts.
1.1.5. Vosvozis site, Greece
The already conducted research revealed that Sidirohori aquifer shows serious groundwater level
decline. Groundwater drawdown from May (beginning of pumping period) to September (end of
pumping period) in certain location reaches 20m, leading to the obvious conclusion that the aquifer
system is overexploited. Moreover, groundwater level decline induces recharge from Vosvozis river and
Ismarida lake, diminishing thus an important source for the life of the wetland ecosystem. Another
threat due to groundwater level decline is the intrusion of seawater in the wetland area, causing thus a
serious alteration in the initial character of this protected ecosystem.
1.1.6. Mancha Oriental site, Spain
The considerable development of the irrigation systems during the period 1975-2000 has caused
significant decrease in the piezometric levels of the aquifer, which have been decreasing continuously
since 1975. A maximum depletion of 100 m of groundwater levels has been reached in 30 years of
exploitation. This water level decrease has also depleted the streamflow from the Jucar River. The
estimated available groundwater resource is 325 hm3/year, while exploitation is close to 400 hm3/year
(exploitations have been increased to 400 hm3/year in 2005, with a distribution of 96 % agriculture, 3.5
% urban water supply, 0.5 % industry). Despite a pumping wells substitution by using surface water has
been carried out in recent years (with a 20 % of reduction), we are dealing with an overdrafted aquifer,
which does not meet the good groundwater quantitative status as stated in the WFD. Furthermore, the
Water Agency has made public offers to buy water rights from farmers (to stop pumping) in order to
protect the river downstream users. Several measures are under study to control the overexploitation:
pumping quotas, prices, improving global irrigation efficiency, pumping substitution by surface water,
etc. It is worthwhile mentioning that the aquifer is planned to be declared as overexploited, which
means that well extractions will be limited, irrigated surface will not be increased and users
communities (irrigation districts) will be set up as a control mechanism.
22
1.1.7. Areuse site, Switzerland
Mountain basins are the most vulnerable environments from point of view of climate change. Their
fundamental sensitivity to temperature changes affects rainfall, snowfall and snowmelt. Climate change
in mountain basins could therefore result in substantial changes in the runoff regime.
Snowmelt runoff is an important source of groundwater recharge for the Areuse Spring. Temperature
changes are particularly significant for region around or below 1000 meters because the winter mean
temperature at this altitude is around 0°C and even small variations in temperature may determine if
precipitation falls are rain or snow. A preliminary evaluation suggested that climate change could indeed
modify the seasonal availability of water at the spring. During the last 40 years, the snow melting period
has advanced by about 1 month and the associated discharge tends to decrease while no trends in the
mean discharge rate can be identified.
Possible effects of climate change on the water use became already noticeable in the past years. After
the dry summer of 2003, some pumping wells within the karst aquifer were abandoned because their
yield became insufficient. In addition, during the dry autumn 2009, the spring discharge (and hence the
river discharge) was too low for hydroelectrical production and likely had also some affect on the river
ecosystem.
1.1.8. De Kromme Rijn site, The Netherlands
Most lowland stream drainage-basins have a high population density and the land use is very intensive.
The permeable subsoil acts as an integrating medium, thus providing a widespread dispersal of leached
nutrients and transmission of water-table lowering. Most of the adaptation options to climate change
will have severe impacts on economic sectors and on individuals.
Over the last 50 years much attention has been given to improving agricultural production, resulting in
higher water demands. The increased population needs more drinking water, which is mainly abstracted
from groundwater. This and other factors have caused changes in groundwater recharge and water
tables to fall. Lower water tables have adversely affected conditions in nature conservation areas.
Furthermore, changes in land use and increased drainage (installation of subsurface drains) have
contributed to this hydrological degradation.
23
1.2. Impacts and threats on substances leaching to groundwater
aquifers due to different land-uses
A common threat to groundwater quality is linked to the non-point source pollution of nitrate leaching
from the soil through the unsaturated zone into the groundwater body. Typically, the nitrate mass
derives from disproportionate use (i.e. amount and timing of application) of fertilizer in agriculture. This
situation is present in many of the test sites, as for example in Spain, where nitrate contents of 125 mg/l
have been observed, in Greece, where nitrates in some boreholes were detected in much higher
concentrations compared to the EU limits, or also in Austria. In the Dutch lowlands, at periodically high
groundwater events, an important part of the incoming nitrate will be denitrified and the soil has a
relatively low binding capacity for phosphate. The Mean Highest Groundwater level is a good indicator
for such events. If and when the soil is saturated with phosphate depends on the presence of metal
oxides (and lime), the historical phosphate surpluses and the current agricultural practice.
Cold climates represent a special condition in this respect since findings of several pesticides from grain
and potato production demonstrate that slowly degradation of pesticides can form an important threat
to deterioration of groundwater resources. Additionally, when the frozen soil subsequently thaws, the
temporary water storages rapidly infiltrate into the subsurface. It is hypothesized, that the use of mobile
pesticides on such areas might represent a particular threat to the groundwater quality. Pesticides have
also appeared in the aquatic system of the Turkish test site with dichlorvos showing very high
concentrations in all sets of experiments.
However, fertilizer and pesticide applications are not the only pollution sources. In the Zagreb aquifer an
entire mixture of emission sources exists comprising leaky sewerage, the city landfill, agriculture, illegal
waste depositories, illegal gravel pits and also industrial facilities. High concentrations of pollutants like
nitrates, atrazine, heavy metals and chlorinated hydrocarbons in groundwater confirm the impacts. At
the Greek site point sources of pollution are given by industrial activities which discharge their
wastewaters in Vosvozis river or in its tributaries in an uncontrollable manner which feed the aquifer
body during the vegetation period.
A comparable mixture of pollution sources is produced by the different kinds of wastes (urban wastes,
inerts, sludge, ashes, and metallic objects) that were dumped at the Italian landfill site leading to the
contamination of groundwater by halogenated (mainly chlorinated) aliphatic hydrocarbons. An
additional threat to residents exists through potential vapours migration through the unsaturated zone.
Due to hydrogeological characteristics and a complex history of pollution the contaminants at the
German “megasite” Bitterfeld show a distinct vertical stratification and strong local variability. The main
components of organic contamination were found to be benzenes and ethenes. Evidence was found for
the in situ transformation (reductive dechlorination) of these substances which shall be confirmed by
the use of constructed wetlands at the laboratory and the field pilot scale.
24
Leaching of substances into groundwater is not only related to excessive pollution but can also be
favoured by hydrogeologic conditions. MGWB 326 in Poland has a very low resistance against pollutions
coming from the terrain mainly because of lack of an insulation Quaternary layer. It is vulnerable to any,
even small pollution resulting in a quick degradation of water resources. The main factors that influence
groundwater quality are high concentration of various economy sectors and infiltration of pollutants
from the Warta river.
Karst aquifers have also specific hydraulic and hydrogeologic characteristics that render them highly
vulnerable to pollution from human activities. The principle sources and causes of the groundwater
pollution at the Swiss test site can be summarized as disposal of wastewater and agriculture. Indicators
of contamination with faecal matter are regularly detected at the spring during flood events.
At two test sites experimental facilities have been set up to study the water movement and the
pollutant fate in the soil and the unsaturated zone. In France five different types of wastes and farmyard
manure are applied to 5 plots and the water quality is monitored within the first meter soil profile by
various devices. The impacts and threats concern the modification of leaching (concentration and fluxes)
due to the effects of organic amendments on soil properties. At the Austrian site 32 lots with 1000 m²
each are operated to evaluate the impacts of growing corn compared to crop rotation on nitrogen
leaching into the groundwater using different fertilizing schemes. In the middle of the lots two high
precision lysimeters were built, one of each located beneath a corn monoculture and a crop rotation lot,
respectively. Data concerning amount and nitrate concentration of the leachate are collected at several
depths.
1.2.1. Grue site, Norway
The major threat to groundwater at the Grue case site is assessed to be leaching of pesticides used in
crop production. The case site represents an area with intensive agricultural production in an area with
cold climate.
Several investigations of pesticides and nitrate in groundwater have been carried out during the period
1995-2007 at the Grue study area (Eklo 1997, Eklo et al. 2002, Eklo et al. 2004, Ludvigsen et al. 2008).
Findings of several pesticides from grain and potato production in several drinking water wells
demonstrate that in cold climate with slowly degradation of pesticides, pesticide leaching can represent
an important threat to deterioration of groundwater resources and groundwater dependent
ecosystems.
In climate with frozen soils in winter, melt water are gathered and temporary stored in local depressions
in the terrain early in spring. When the frozen soil subsequently thaws, the temporary water storages
rapidly infiltrate the subsurface. It is hypothesized that use of mobile pesticides on such areas might
represents a particular important threat to deterioration of groundwater in cultivated areas.
25
1.2.2. Koycegiz-Dalyan (KD) site, Turkey
The agricultural activities based on polyculture, basically cotton, citrus fruits, pomegranate, wheat, corn,
and horticulture. Annual fertilizer consumptions for the year 1998 in the site was calculated as 146.8
kg/ha/year N, and 54.2 kg/ha/year P, which are almost twice the country’s averages. Pesticides use in
the area is approximately 12 kg-l/ha which is quite high compared to overall annual consumption value
for all Turkey (1.25 kg-l/ha).
In the vicinity of the study area, nitrate analyses were made at 6 different GW stations. Average nitrate
concentration was 15.8 mg nitrate/L and a maximum nitrate concentration was 21.7 mg nitrate/L.
Surface and bottom water samples were taken from 16 stations along the lagoon channel network and
Alagol and Sulungur Lakes. Four pesticides had appeared (endosulfan, deltamethrin, dichlorvos and
diazinon) in the aquatic system. Analysis results were around and/or slightly higher than the limits
except dichlorvos. Dichlorvos appeared in all four sets of experiments with very high concentrations.
1.2.3. Caretti site, Italy
The contamination of groundwater is represented by halogenated (mainly chlorinated) aliphatic
hydrocarbons, mainly Perchloroethylene (PCE), Trichloroethylene (TCE) and Vinyl Chloride (VC).
The original source material (solid-liquid mixture of chlorinated pitches with unknown composition),
once disposed in the two dumps, induced gravity-driven percolation of DNAPL down to the bottom of
the original clay pits. The wastes in the pits consist of a highly heterogeneous mixture of urban wastes,
inerts, sludge, ashes, and metallic objects, more or less dispersed in a silty-clayey matrix originating from
the ground works connected to the clay quarrying and dumping operations in the past. Analyses of the
silty-clayey matrix mixed with the wastes, performed in some samples collected over the 2001-2003
period, show concentrations exceeding regulatory limits of metals (As, total Cr, Ni), chlorinated ethenes
and PAH.
At Caretti site impacts on groundwater quality are really serious. The main threat interests residential
people and it is represented by potential vapours migration through the unsaturated zone.
1.2.4. Feucherolles site, France
Three composts have been applied once every two years since September 1998: a co-compost of
sewage sludge and green wastes (SGW), a municipal solid waste compost (MSW), a biowaste compost
(BioW). A farmyard manure (FYM) is used as reference organic amendment and a control treatment is
realized without organic amendment (CONT).
Five plots corresponding to each treatment have been instrumented to follow water fluxes
(tensiometers and TDR probes) in the first meter soil profile and to monitor water quality (wick
lysimeters, porous cups). This instrumentation has been done in 2004. Since then, we collect data on a
weekly basis for water content and weekly/monthly basis for soil solution collection. Lately (October
26
2009) piezometers have been installed in the middle of each plot. They will allow to monitor water
quality at 2 m depth in the perched water table formed in winter.
The impacts and threats concern the modification of leaching (concentration and fluxes) due to the
effects of organic amendments on soil properties. Several elements or potential contaminants are
concerned: dissolved organic carbon (DOC), nitrate and other major anions, trace metals and pesticides.
Monitoring the presence of other trace organic contaminants such as PAH, LAS and phthalates is also
planned since some of these compounds are present in significant amounts in urban waste composts.
1.2.5. Murtal site, Austria
In the centre of the Murtal aquifer (near Wagna) a large scale agricultural experiment is run since 1987
consisting of 32 lots with 1000 m² each. It is the aim of this setup to evaluate the impacts of growing
corn compared to crop rotation on nitrogen leaching into the groundwater using different fertilizing
schemes. In the middle of the lots two lysimeters were built 1992, one of each located beneath a corn
monoculture and a crop rotation lot, respectively. Data concerning amount and nitrate concentration of
the leachate are collected at several depths. With the help of geophysical site investigations 8 different
soil types could be identified, the thickness of the top soil varies between 25 and 215 cm.
Based on the lysimeter data the two models SIMWASER and STOTRASIM that describe the soil water
balance and the transformation of nitrogen respectively have been calibrated. It is the purpose of the
models to compute the leachate of nitrogen at the bottom of every individual “hydrotop” (unique
combination of cultivation, soil thickness and soil type).
1.2.6. Zagreb site, Croatia
Developments of industry and fast growth of the City of Zagreb have considerably affected quality of
groundwater in this aquifer system. Increasingly progressive groundwater pollution in the
heterogeneous aquifer system underlying the City of Zagreb has been observed for the last twenty-five
years. The most significant pollution sources are leaky sewerage, the city landfill, agriculture, illegal
waste depositories, illegal gravel pits, and also industrial facilities. High concentrations of pollutants like
nitrates, atrazine, heavy metals and chlorinated hydrocarbons in groundwater confirm the impacts of
pollution sources on groundwater quality.
1.2.7. Vosvozis site, Greece
Land uses in the Vosvozis river basin are mainly agricultural, cattle breeding, industrial and
urban/residential. Point sources of pollution are formed from industrial activities which discharge their
27
wastewaters in Vosvozis river or in its tributaries in an uncontrollable manner and by private septic
tanks (half of the population is served by such systems).
Agriculture is the diffusive source of pollution for the study aquifer system, merely through the
application of fertilizers and pesticides. The already conducted research showed that the main pollutant
present in the groundwaters in nitrates, which in some boreholes was detected much higher than the EC
standards. DUTH has started monitoring pesticides in groundwaters of Vosvozis river. Initial results
showed that they currently do not seem to pose a threat for the groundwater system of the study area.
1.2.8. Mancha Oriental site, Spain
The representative crops grown in the area are corn, barley, wheat, sunflowers, and alfalfa. The crops
require high quantities of fertilizer and water to maintain elevated agricultural yield. These agricultural
activities have been admitted to be potential sources of nitrate pollution due to extensive application of
inorganic fertilizers. The continuous fertilizer application during the last decades has led to observe
nitrate concentrations higher than 50 mg/l, which is the maximum allowable concentration (Drinking
Water Directive, 80/778/EEC and its 49 revision 98/83/EC). It should be pointed out that nitrate
contents of 125 mg/l have been observed. However, significant differences have been found within the
different domains considered. All these facts ended up with the declaration of the aquifer as a nitrate
vulnerable area by the Castilla-La Mancha regional government (2003).
1.2.9. Areuse site, Switzerland
Karst aquifers have specific hydraulic and hydrogeologic characteristics that render them highly
vulnerable to pollution from human activities. Karst groundwater becomes polluted more easily and in
shorter time periods than water in non-karstic aquifers.
The principle sources and causes of the groundwater pollution in Areuse catchment area can be
summarized as disposal of wastewater and agriculture. Indicators of contamination with faecal matter
are regularly detected at the spring during flood events. Due to more intense precipitation events in the
future, such contamination events may become more frequent.
1.2.10. Czestochowa site, Poland
MGWB 326 has a very low resistance against pollutions coming from the terrain mainly because of lack
of an insulation Quaternary layer. The reservoir (generally unconfined aquifer) is exposed on a
considerable area and thus it is vulnerable to any, even small pollution resulting in quick degradation of
water resources. Surface water – groundwater interaction cause infiltration of pollutants from the
Warta river as well.
28
The following changes are foreseen in the land use: (i) spatial expansion of the city of Czestochowa, (ii)
development of regional systems of road transport, (iii) development of tourism based on objects of
cultural heritage, environmental attractions and mining heritage parks. The main factors that have
significant influence on groundwater quality are: (i) High concentration of various economy sectors and
very intensive exploitation of groundwater resources, (ii) Hydro - geological conditions which make
water layers sensible to infiltrating pollutions.
The research done by the Polish Geological Institute enabled to identify the pollution sources in the area
and estimate their contribution to groundwater quality: Geogenic – 15%, Anthropogenic – 45% and for
40% of pollutions their origins were not defined.
1.2.11. Bitterfeld site, Germany
The contaminants at the Bitterfeld site show a distinct vertical stratification and high concentration
levels alternate with low or zero levels. The experience during the last years of groundwater sampling
gives a clear evidence of a strong local variability of the detected contaminants. These two facts make it
very difficult to state distinct concentration levels as well as certain organic substances or compounds.
The ‘main components’ of organic contamination were found to be chlorobenzene, 1,2dichlorobenzene, 1,4-dichlorobenzene, benzene, trichloroethene, cis -1,2-dichloroethene and trans- 1,2dichloroethene. High organic pollution with halogenated hydrocarbons was confirmed in both aquifers.
Contamination of the groundwater with inorganic pollutants (e.g. heavy metals, arsenic, etc.) has proven
to be of minor importance. The only noteworthy feature is the high levels of sulfate (up to 1000 mg/l)
and chloride (about 1300 mg/l).
The regional distribution of contaminants reflects in general their different sources and pathways and
gives first results from a regional point of view, depending on the land-use classification of specific
areas, e.g. industry, mining, settlements, agricultural and alluvial plains/meadows. Based on parts of this
data set (290 wells, 1200 samples, each up to 180 contamination parameters), a specific contamination
profile for this region was derived on the base of available monitoring data within the SAFIRA project.
The influence of important parameters like detection limits and the statistical measures to estimate the
average detected concentration on the results of the ranking procedure were investigated.
Furthermore, a cluster analysis with the two criteria, detection frequency and average-detected
concentration, reveals substances with similar behaviour in the environment in terms of persistence and
mobility, and improves the contamination profile at the regional level. It was found that the median is
the most suitable measure. High median values of more than 10 mg/l were calculated for cis /trans-1,2dichloroethene, 1,2-dichloroethane, chloroethene and monochlorobenzene.
Using concentration and compound specific analysis (CSIA), several studies were performed in Bitterfeld
to investigate the in situ transformation of chlorinated ethenes and benzenes. Findings indicated the
reductive dechlorination of chlorinated ethenes and benzenes. It was suggested that
29
monochlorobenzene (MCB) was degraded under the anoxic conditions present in the aquifer. A further
investigation using stable isotope tracers combined with in situ and well laboratory microcosms
confirmed the mineralization and assimilation into microbial biomass of carbon derived from MCB.
The research within GENESIS will focus on model systems, in this case constructed wetland systems with
different sizes is planned, for the transfer of contaminated groundwater through a subsurface wetland
system to an open water body: 1) laboratory scale and 2) a field pilot scale wetland, both running with
contaminated groundwater from Bitterfeld. Previous research found reductive dechlorination of the
dichloroethene via vinyl chloride to ethene and corresponding compound specific isotope fractionation
and presence of groups of microorganisms capable of reductive dechlorination in a small laboratory
scale wetland system.
1.2.12. Po valley site, Italy
Because the dominant land use in the study area is “annual crops”, the most important class of pesticide
in the study area is represented by herbicide. In Pavia province a high use of fungicides is recorded, but
most of the hill part of this province is under vine crop.
Regional administration reports that nitrates are the most important pollutant. The Administrator
already identified vulnerable areas. In agriculture, the main distribute specie is amide. Urea is the most
important fertiliser on maize crop. Animals and population are further important sources of nitrogen in
the environment. A gap in knowledge exists in the description fate of pesticides and nutrients from
groundwater to fontanili and from adjacent fields to fontanili.
1.2.13. De Kromme Rijn site, The Netherlands
Sources of contamination to the deep and shallow groundwater in the study area include contamination
with nitrate, phosphate and pesticides due to agriculture and various contaminations caused by roads,
industrial sites, landfills, weed control, urban constructions and effluent discharges of wwtp’s.
At periodically high groundwater events, an important part of the incoming nitrate will be denitrified
and the soil has a relatively low binding capacity for phosphate. The Mean Highest Groundwater level is
a good indicator for such events. If and when the soil is saturated with phosphate depends on the
presence of metal oxides (and lime), the historical phosphate surpluses and the current agricultural
practice.
Combating diffuse pollution by nutrients is complicated by various factors: the cause-effect relationships
are less clear and there is a large time lag between taking measures and actually seeing positive effects.
30
1.3. Impacts and threats on groundwater dependent ecosystems
interacting with surface water
In principle threats to groundwater dependant ecosystems may have a quantitative background (e.g.
lowered water table), consist of a water quality issue (any kind of pollution) or are a combination of
both (see previous chapters). In the case of interaction between groundwater and surface water bodies
the ecosystem within the riparian zone (i.e. discharge area) will always be involved. In the following
overview these test sites are shortly introduced that predominantly deal with impacts on groundwater
dependant ecosystems.
Due to surface streams or shallow groundwater that may contain significant concentrations of nutrients
the risk of eutrophication of ecosystems exists in such different environments as the Greek coastal
lagoon (nutrients coming form waste water discharge) and the shallow weathered bedrock aquifer in
the Czech Republic (nutrients coming as leachate from agricultural fertilizer). At the latter site the
situation is even worsened because of acid athmospheric depositions influencing the natural pH and the
seepage of mine waters containing a variety of heavy metals. These elements have a direct toxic or
inhibit effect on the fluvial biota as the riverbed sediments are incrusted by iron and manganese oxides
to the dept about 10 – 15 cm. In the Po valley, Italy, a special GDE exists by so called fontanili, which
basically are artesian wells dug by monks in the middle age. The role of the riparian strip is of particular
interest in studying the movement and fate of pesticides and nutrients from groundwater to fontanili
and from adjacent fields to fontanili.
Equilibrium shifts in freshwater bodies, as a result of nutrient loading, have been reported at the Dutch
test site. Water bodies characterised by clear water, macrophytes and predator fish (pike and pike
perch) have been replaced by turbid water systems dominated by algae and freshwater bream, which is
not a popular recreational fish.
Another ecosystem test site is given by the Niepolomice Forest in Poland. It is a relatively large (ca. 80
km2), groundwater-dependent forest complex with wetlands and marsh areas occurring in several parts
of the forest. Impact of long-term changes of water balance (including the impact of climate change) and
anthropogenic pollution on the ecosystem functioning have been studied. The aquifer became a testing
ground for different tracer methods to explore the dynamics and time scales of groundwater renewal
and to build a good conceptual model, which is the basis for 3d numerical flow and transport modeling.
The discharge pattern of Luleå river has changed after regulation, with high discharge values during the
autumn and the ice-covered winter period and a decreased spring peak. Instead of overflooded areas
during snowmelt, the water balance shows a net outflow of water in May, which lowers the water level
in the reservoir one metre. During the summer, the water balance is positive and water is stored in the
reservoir. The riparian zone processes are therefore altered compared to an unregulated river. Fe, Si,
and P are retained in the reservoirs. This retention can be an effect of increased diatom production in
stored water. Other chemical elements which are locked in reservoirs are S, DOC and Mn.
31
In detail the following site characteristics of groundwater dependant ecosystems are encountered at the
respective case study sites.
1.3.1. Grue site, Norway
The main ecosystems influenced by groundwater hydrology and quality are the riparian zone in the
discharge zone along the river Glomma. These ecosystems can be affected by groundwater
contaminations and changes in groundwater hydrology.
The river Glomma is the main receptor of the groundwater discharge from the case study area and will
therefore be affected if the aquifer became polluted,. However, compared to the riparian zone, the
proportion of water in the river originating from the agriculturally influenced aquifers along the rivers
will be fairly small.
A small groundwater influenced lake, the Lake Gruetjern, previously occurred within the case study
area. However, recently the lake has been filled in by the Norwegian Water Resources and Energy
Directorate as a part of an improvement of the flood protection constructions along the river. This may
illustrate that groundwater dependent ecosystems are at risk of several reasons and may stress the
importance of taking into consideration the requirements of the remaining groundwater dependent
ecosystems in future groundwater management.
1.3.2. Rokua site, Finland
The main threats at Rokua are related to forest drainage of peatlands surrounding the esker, climate
change, some urbanization and to some extent water regulation. The main concern is that water levels
in small lakes situated in the groundwater aquifer have been declining for the past decades. Different
reasons for this decline have been discussed such as climate change or the land use and drainage, but
this is yet uncertain as research is lacking on this complex ecosystem. It is essential for local residents,
tourism and property owners of the Rokua communities to solve the reasons for the decline. The aquifer
has a large value for recreation and nature conservation. Part of the aquifer is already protected by
Natura 2000.
1.3.3. Koycegiz-Dalyan (KD) site, Turkey
Variations and changes in climate might be significant factors for the overall changes in the flow regime.
During extreme precipitation events, such as heavy rain fall and storms, since most of the precipitation
is lost as run-off, less recharge to groundwater is expected. There are many springs and hot springs in
the watershed. Particularly, the hot springs are significant, as they are among the facilities which attract
tourists to visit the area. Coastal aquifers are sensitive to changes in water budget due to the interaction
32
between fresh and salt water in the subsurface along the coast. As recharge is decreased, the position of
the freshwater and saltwater interface will move inland at a rate that is proportional to the decrease in
recharge, and water quality can be compromised to the extent that freshwater availability is limited.
1.3.4. Vosvozis site, Greece
Komotini’s wastewater treatment plant discharges treated wastewaters in Vosvozis river. Special
attention should be focused on the Komotini’s industrial area which is not located within Vosvozis river
basin but adjacent to it. This industrial area comprises plastic, paper, wood, food processing plants, as
well as a thermo-electric power producing plant. Industrial waste waters are disposed in Filiouris river
which discharges in the coastal lagoon ecosystem, thus forming a serious threat to it. The already
conducted research showed that the main threat to the wetland ecosystem is eutrophication,
diminishing its aerial and seawater intrusion which seriously affects the fragile wetland ecosystem.
1.3.5. Sumava site, Czech Republic
Most of the former farmlands and meadows in the Lenora area were changed for pastries with an
increased number of cattle breeding in the area. The cattle is held both on open pastries and inside
stables with significant liquid and solid waste production that has been used for crop fertilization back at
the pastries and meadows.
The impacts on groundwater are significant, because of a quick response in water infiltration. There’re
increased concentrations of nutrients present in the ground water (nitrates, nitrites, ammonia,
phosphates...etc.) having negative impacts on groundwater quality. The results are decreased values of
present ground water resources, because major ground water flow occurs in a shallow weathered
bedrock aquifer only.
Even more important impacts there’re negative influences on peat bogs and marshlands because of its
oligotrophic ecosystems, which are very sensitive to nutrient leachate from agriculture. The negative
impact combines with acid atmospheric deposition that influences natural basic pH of valley peat bogs.
There exists a risk of eutrophisation especially from surface streams or shallow groundwater that may
contain significant concentrations of nutrients.
The leaching mine waters are a significant source of a variety of heavy metals, in the stream of Golden
Creek there have been also high contents of iron and manganese observed. These elements have a
direct toxic or inhibit effect on the fluvial biota as the riverbed is incrusted by iron and manganese
oxides to the dept about 10 – 15 cm. This situation is well describing importance of bottom layers
permeability and connectivity to hyporheic zone. To assess the direct impact of mine waters, there’s
necessary to perform detailed flow experiments with use of appropriate tracers. Besides, there can be
33
indicia of mining technologies detected – namely limited solvents applied during the construction of
Nadeje adit and possible relicts of mine installation (esp. floating and sedimentation cycle).
1.3.6. Czestochowa site, Poland
Attention is focused on the NATURA 2000 area covering the southern part of the Wiercica river basin,
where headwaters of the river are located (springs controlled by groundwater discharge). Good water
quality as well as specific climatic conditions are favourable for existence of mosaic of biotops: in dry
and warm conditions some southern species are met while in wet and cold - mountain and boreal ones.
In the area significant groundwater resources are documented (30 000 cum/day), planned for
exploitation after 2025.
1.3.7. Bogucice site, Poland
Eastern part of the upper aquifer is occupied by Niepolomice Forest. This is a relatively large (ca. 80
km2), compact, groundwater-dependent forest complex. The depth of water table is generally shallow,
with wetlands and marsh areas occurring in several parts of the forest. The Niepolomice Forest is part of
NATURA 2000 network (code: 12 0002). Impact of long-term changes of water balance (including the
impact of climate change) and anthropogenic pollution on the ecosystem functioning within the
Niepolomice Forest has been studied.
The GDE protection needs good conceptual model with dynamics and time scales of groundwater
renewal. The aquifer became a testing ground for different tracer methods, used in combination with 3d
flow and transport modeling.
There is also some evidence of contamination from a linear source of pollution, a contaminated river
draining large municipal landfill located close to the southern border of the aquifer.
1.3.8. Lule site, Sweden
In order to study hydropower regulation impact on river-groundwater interaction, two study locations
were chosen: Luleå river case study was taken as a primary location and Kalix river case study (pristine
conditions) as reference one. The sites were chosen to be similar in climate, topography, river width,
geological and geohydrological settings. Difficulties with site identification are dense forest areas, steep
embankments of both rivers in some places, and private land use.
Discharge maximum in Kalix river occurs in May-June and has its winter base flow much lower, than that
in Luleå river. Kalix river is mainly fed by dominating groundwater inflow during winter, while high water
level in Luleå river reservoirs most probably effects this pattern and we might observe water loss from
the river. The discharge pattern of Luleå river has changed after regulation, with high discharge values
34
during the autumn and the ice-covered winter period and a decreased spring peak. Instead of
overflooded areas during snowmelt, the water balance shows a net outflow of water in May, which
lowers the water level in the reservoir one metre. During the summer, the water balance is positive and
water is stored in the reservoir. The riparian zone processes are therefore altered compared to an
unregulated river. A thermocline is observed in the reservoir at a depth of 10-15m. Below this depth
temperature, pH and dissolved oxygen decrease. However, the bottom water is still well oxygenated.
As a result different from prior to regulation period amount of nutrients and other elements reach the
Gulf of Bothnia. This applies also for the year season when it happens. Reservoirs construction and flow
fragmentation as a result cause river to act as a sink. In such way Fe, Si, and P are retained in the
reservoirs. Si is also trapped in water storages. This retention can be an effect of increased diatom
production in stored water. Among other chemical elements and compounds which are locked in
reservoirs are S, DOC, Mn.
Kalix river receives most of its dissolved and particulate fractions from schist and spatially distributed
outcrops of dolomite and limestone, located in Caledonian mountains. Midsummer flow dominates by
high Ca concentrations, indicating large influence of water from the mountain area. During May when
snowmelt appears in plane part of the river, water from woodland areas has major influence. This is
indicated by elevated content of Si in river water. Si is related to TOC (peatland is a source), which is also
high during the spring snowmelt.
1.3.9. Po valley site, Italy
Fontanili are the dependent GW ecosystem studied into the project. They are mainly located in an
agricultural landscape. Tough they are artificial systems they are heritage landscape elements. The main
thread of these ecosystems comes from agriculture: pesticides and nutrient pollution and from land use
change, in particular from urbanisation.
1.3.10. De Kromme Rijn site, The Netherlands
Eutrophication (nitrogen and phosphorus) is the big issue for regional waters, where drainage of
agricultural land leads to nutrient levels far exceeding standards. Eutrophication is probably aggravated
locally by effluents from WWTPs that do not use technologies to extract nutrients, by urban storm
waters, and by proximity to traffic routes via atmospheric deposition of nitrogen.
Equilibrium shifts in freshwater bodies, as a result of nutrient loading, have been reported. Water bodies
characterised by clear water, macrophytes and predator fish (pike and pike perch, popular with
recreational fishermen) have been replaced by turbid water systems dominated by algae and freshwater
bream (Brasem brasem), which is not a popular recreational fish. Standards in regional waters are
35
exceeded for many hazardous substances (heavy metals, pesticides, PAHs and PCBs), but usually to a
lesser degree than for N and P.
1.4. Possible gaps with the WFD and/or GWD
Based on the experience within the relevant test sites possible gaps of the WFD and the GWD are
related to unconsidered processes, non-existing tools, missing thresholds neglecting uncertainty bounds
and implementation glitches.
Climate change is not directly covered in the WFD or the GWD. However, the changed water availability
could lead to an imbalance between water availability and water use, violating Art. 4 of WFD, which
imposes to ensure equilibrium between withdrawal and renewal of water. Furthermore, important gaps
exist in knowledge about spreading patterns and advisory tools to prevent pesticide pollution of
groundwater and groundwater dependent ecosystems in areas with winter climate and intensive crop
production.
Such tools will be important to be able to fulfil the implementation of the programmes of measures
required by the directives. In the case of unmanaged landfills groundwater vulnerability maps
concerning potential sources of point contamination should take both active risk centres and
old/inactive risk spots into account.
Definition of threshold values and environmental indices should not only reflect on the preservation of
human health but also consider the needs of wetland ecosystems. In general, uncertainty in threshold
values might reveal difficulties in assessing environmental and resource costs in this area.
Though the peatlands lay in the groundwater discharge zone, these areas have not been considered as
part of the aquifer or as part of the Natura 2000 protection area. An improved conceptual model for the
groundwater dependent lake systems could solve the situation. For other test sites an integrated water
management plan has not been developed yet.
In the Netherlands a special situation exists since over many centuries natural water systems have been
strongly adjusted and artificial structures built. Due to the high population density and to cope with an
expected increase in flood risks multi-functional land use is seen as a key element of the solution to
many of the current problems.
In detail the following possible gaps within the WFD and the GWD are encountered at the respective
case study sites.
36
1.4.1. Grue site, Norway
Despite the importance of pesticides and nitrate in the GWD, as illustrated by the common European
groundwater standard for these substances, there are still important gaps in knowledge about spreading
patterns and advisory tools for pesticides in areas with cold climatic conditions.
A main objective in the study at Grue is to improve the knowledge base for these issues and develop and
test of advisory tools for measures to prevent pesticide pollution of groundwater and groundwater
dependent ecosystems in areas with winter climate and intensive crop production.
Such new knowledge and tools will be important to be able to fulfil the implementation of the
programmes of measures required by the directives in a satisfactory manner.
Another important contribution to the knowledge base for future implementing of the WFD and GWD is
the new scenarios of impacts of land use on groundwater under altered climatic conditions.
1.4.2. Rokua site, Finland
At present, the main treats seem to come from areas outside the actual area classified as the aquifer.
The peatlands lay in the groundwater discharge zone and these areas have not been considered as part
of the aquifer or as part of the Natura 2000 protection area. For protection of groundwater dependent
ecosystems we need to better define the impacts of drainage and also the natural variability or impact
of climate change. Also we need a better conceptual model for the groundwater dependent lake
systems within the esker.
1.4.3. Koycegiz-Dalyan (KD) site, Turkey
There are water unions in the watershed; however, an integrated water management plan is not
developed yet. Thus, there are lots of wells in the watershed, with a depth of less than 10 m used by the
households. Almost half of the wells are illegal, so the amount of water abstracted from the
groundwater cannot be controlled, which causes the excess use of groundwater and seems to be threat
on the system. Preventive actions towards decreasing the impacts of fertilizers and pesticides have been
initiated by means of a protocol related to good agricultural practices in the special protection areas.
1.4.4. Caretti site, Italy
Caretti site represents a story that can be replayed in other countries with environmental laws less
restrictive with respect to Italy ones. In other words, what took place in Italy on the ‘60s-‘70s could take
place again in other countries less developed concerning environmental protection laws.
37
A peculiar topic arising from this case study is the need of groundwater vulnerability maps that,
concerning potential sources of point contamination, take into account both active risk centres (farms,
chemical plants, nuclear plants,…) and old/inactive risk spots (like dumps, quarries, landfills, …).
Regulatory laws could oblige to define sensitive areas around these potential sources of contamination
and to make hydrogeological surveys before urbanization processes.
1.4.5. Zagreb site, Croatia
Possible gaps might be expected regarding the assessment of the chemical status for the groundwater
bodies in Zagreb area being at risk of failing the environmental quality objectives for groundwater. This
assessment should be based on groundwater (environmental) quality standards and threshold values of
pollutants and indicators of pollution. Unfortunately, the extent of interactions between groundwater
and associated aquatic/terrestrial ecosystems, as well as the geochemical background values are still
under investigations, so the threshold values might be underestimated or overestimated. According to
the Guidance Document No 1of European Commission (Economics and the Environment – The
Implementation Challenge of the Water Framework Directive), uncertainty in threshold values might
reveal difficulties in assessing environmental and resource costs in this area. Furthermore, currently
there is not enough evidence on the complete list of all pollutants characterising GW bodies in Zagreb
area as being at risk.
1.4.6. Vosvozis site, Greece
The main issue that should be addressed through Vosvozis case study concerning the WFD – GWD is the
definition of threshold values and environmental indices not only for the preservation of human health
but also for the wetland ecosystem.
1.4.7. Areuse site, Switzerland
The main threats to the system are related to climate change that is not directly covered in the WFDGWD but is also an important process investigated within the GENESIS project. However, the changed
water availability due to climate change could lead to an imbalance between water availability and
water use, violating Art. 4 of WFD, which imposes to ensure equilibrium between withdrawal and
renewal of water.
1.4.8. De Kromme Rijn site, The Netherlands
Management and organisation of the watersystem is a major cause of the poor ecological score. The
factors to be considered of importance comprise water table management; presence of dykes, barriers
38
and pumps; hardening of river banks and maintenance (mowing, duckweed, too much or too little
dredging).
The Catchment Vision of the Waterboard provides a blueprint for policy development during the period
up till 2050. With regard to reducing flood risk, the following preferential sequence of measures is
upheld: (1) holding on to the water as much as possible, i.e. micro-scale buffering in the headwaters of a
catchment; (2) if that is not possible, storing it within the catchment, i.e. meso-scale buffering along the
transporting subsystem; (3) if all fails, only then discharging it to the downstream area.
So-called search areas have been identified for creating storage of water, intended as peak flow storage
for combating downstream flooding and seasonal storage for combating problems caused by prolonged
droughts. With respect to flood prevention, the target is to become ‘climate proof’, i.e. to solve
problems induced by climate change in a region itself, and thus to not ‘export’ the problems to the
downstream areas. In general, multi-functional land use is seen as a key element of the solution to many
of the current problems.
1.5. Impacts and threats on groundwater systems and River Basin
Management Plans
Within the WFD the river basin was introduced as a single system of water management, i.e.
administrative or political boundaries were replaced by geographical and hydrological units. The WFD
substitutes several older and diverse directives and requires that at the river basin all existing
technology-driven source-based controls must be implemented to limit water pollution.
For surface waters good ecological status (quality of the biology community in combination with
hydrological characteristics) and good chemical status are postulated by the WFD. Furthermore, other
uses or objectives are foreseen that either imply higher protection measures or that, in special cases,
allow for derogations from the overall requirements. Such cases include flood protection, drinking water
supply, navigation or power generation. For groundwater, likewise, good chemical (no direct discharge
into aquifers, monitoring requirements for groundwater bodies) and quantitative (abstraction limited to
sustainable resource) status are called for.
To coordinate the efforts towards the goal of good status for all waters river basin management plans
(RBMPs) had to be elaborated. The key objectives comprise general protection of the aquatic ecology,
specific protection of unique and valuable habitats, protection of drinking water resources, and
protection of bathing water. Each RBMP is a comprehensive document of how the objectives set for the
river basin are to be reached within the defined timescale including an assessment of the existing
39
legislation and if additional measures will be necessary. Additional components consist of an economic
analysis of water use and the need for public participation.
At the moment RBMPs exist only for some of the countries where the GENESIS test sites are located.
Turkey, Switzerland and Croatia are currently not implementing the WFD. In Spain and Greece
consultations have not yet started and in Poland consultations await adopting. Thus, active RBMPs exist
for Norway, Sweden, Finland, Germany, The Netherlands, France, Italy, Austria and the Czech Republic.
However, in some cases (e.g. France and Finland) the test sites are not really attached to a surface water
network. On the basis of the Austrian RBMP the potential use of the discussed threats to groundwater
systems and the suggested counteractions shall be evaluated.
Austria is drained by the three major European rivers Danube, Elbe and Rhine, of which the Danube
catchment in Austria is by far the largest of the three. The Lower Murtal aquifer is attached to the river
Mur that discharges into the Drava river which flows into the Danube in Croatia. On a national scale,
groundwater pollution by point and diffuse sources as well as quantitative pressure through withdrawals
is estimated within the Austrian RBMP. Waste water treatment plants and abandoned hazardous sites
are mentioned as potential point sources; however, due to only local impacts there is no risk for the
good status of an entire groundwater body. Diffuse sources of pollution are existing through input of
nutrients and pesticides from agricultural land management. The average nitrogen surplus in 2007 is 35
kg/ha. Based on surveys between 2006 and 2008 3 out of 136 groundwater bodies do not have good
chemical status due to nitrate concentrations but all groundwater bodies comply with pesticide
thresholds. Only 3% of the total groundwater resources are extracted for consumption purposes.
The test site Lower Murtal aquifer is classified as an observation area indicating that the good chemical
status is still met but that first measures to identify the sources of pollution have to be started. More
than 30% of the observation wells (25/56) exceed the Austrian nitrate concentration threshold of 45
mg/l in groundwater. An increasing trend of nitrate concentrations in the aquifer around the agricultural
research station in Wagna between 2002 and 2007 could be successfully reversed. It is explicitly stated
in the Austrian RBMP that the prediction of the impacts of initiated actions to reduce pollutant input is
extremely difficult since the heterogeneous soil and subsurface conditions combined with varying
meteorological conditions strongly influence transfer and reaction processes.
With respect to diffuse pollution sources originating from the agricultural sector (i.e. nitrate) legislative
and monetary measures have already been implemented. Legislative measures comprise:



periods where nitrogen fertilizers may not be applied,
regulations for storage of animal manure and
quantitative limitations of nitrogen fertilizers that may be applied.
Financial incentives include among others:


application of crop rotation,
taking land out of agricultural production,
40




lot specific documentation of agricultural practices,
application of Nmin method,
sowing of catch crops with corn and
continuing education.
Future measures that are planned to be implemented consist of



crop specific fertilizer application and fertilizer application based on measured volumes of
remaining nitrate in soil
abdication of fertilization in autumn after harvest of main crop and
increase of storage capacity to enable regional animal manure management.
Finally it is emphasized that it might be difficult to timely evaluate the above measures due to long
groundwater renewal times (up to 30 years in some areas).
Summarizing, the major impacts and threats to groundwater systems as well as general, and in some
cases also specific, measures to counteract are included within the national RBMPs. However, due to the
scale of the basin perspective little attention was attributed to the significance of local hydrogeological
and meteorological conditions, though the importance of these factors is acknowledged. For most of the
GENESIS test sites the national RBMP do not provide new information since the sites were actually
selected because of existing problems with groundwater quality and/or quantity. Thus, the national
RBMPs can be seen to give valuable input as starting points with respect to suggested measures for the
process oriented research work in GENESIS. Moreover, the modelling and scenario WPs will enlarge the
available toolbox to quantify and assess the impact of land use scenarios onto groundwater systems and
GDEs.
2. A general overview of modeling approaches used and their
purposes
By this chapter we wanted to document for which purposes what kind of models have already been
applied at the test sites. In particular, the focus is on data needs and availability as well as on
identification of modeling requirements.
At some sites a lot of modeling experience already exists in diverse aspects, thus the aim is at extension
or further refinement. Higher spatial resolution of existing 3D flow and transport regional model (Visual
Modflow Pro) will be introduced at the Bogucice site. Also, improvement of model structure, better
characterization of surface water – groundwater interaction and inclusion of GDE (more stable isotopes
measurements needed) problems is envisaged to better define GWD requirements with respect to
DWPA and GEPA.
41
At the French experimental site the plot scale is the spatial scale of interest. For water transport a
combination of HYDRUS_1D and the crop model STICS is applied. The model CANTIS has been used to fit
the decomposition of organic matter and N dynamics in the top soil. The CANTIS model is integrated as a
module in the transport model PASTIS (Prediction of Agricultural Solute Transformations in Soil). PASTIS
will simulate nitrate losses and balances in each treatment.
A similar model approach was developed at the agricultural test site in the Murtal aquifer. Numerical
models describing the soil water balance (SIMWASER) and the transformation of nitrogen (STOTRASIM)
are being combined to compute the leachate of nitrogen at the bottom of every individual “hydrotop”
(unique combination of cultivation, soil thickness and soil type). Furthermore, data sets from monolithic
high precision lysimeters (sine 1987) may be used to validate unsaturated flow and transport models
and their coupling with a groundwater model in order to predict the impact of land use changes on the
water cycle.
To illustrate how washing sites for pesticide spraying equipment might contaminate neighbouring
drinking wells, the pattern of groundwater flow in a small area was simulated with Modflow and
ModPath at the Grue site. To illustrate the importance of diffuse pollution from different soils and the
leaching of different pesticides, MACRO_DB and PRZM have been used. However, the models have not
been coupled, and the leaching models have not been calibrated and validated against results from field
experiments.
For the Spanish site a socio-hydro-economic modelling framework is developed which allows selecting
sustainable cost-efficient measures and management strategies to achieve a good quantitative and
chemical groundwater status in an uncertain environment. An optimization model is a central element
that enables to define efficient fertilizer allocation in agriculture so that the environmental constraints
can be met. Since emissions are what can be controlled, but the concentration at the receptor sites are
the policy targets, it is necessary to relate both through the proper numerical simulation of the
pollutants leaching, transport and fate within the aquifer. The response matrix describes the influence
of pollutant sources upon concentrations at the control sites over time. Crop production and nitrogen
leaching functions can be derived from agronomic simulation models like EPIC.
For a couple of other test sites clear visions exist about future numerical model applications. At the
Italian landfill site the general idea is modeling organic compounds migration from the source to the
human receptors. The needs related to modeling are taking into account biochemical attenuation
processes and assess the risk for human receptors related to vapours migration through the unsaturated
zone. Missing data include hydraulic connection between aquifers and assessment of biodegradation
rates by means of contaminant isotopes. For the Zagreb aquifer the universal transport modeling
approach consists of achieving a better understanding of the transport regime of heavy metals and
quantifying the dominant controlling process.
The Greek partner plans to use the SWAT model to predict the impact of various land management
practices on water, in large complex watersheds with varying soils, land use and management conditions
42
over long periods of time. Furthermore, DUTH has recently installed 3 lysimeters on selected sites.
Results will be used as boundary conditions for groundwater modelling.
At the Dutch site an integrated hydrological model comprising modules for saturated groundwater,
unsaturated soil water and surface waters is already in operation. To avoid long computation times
simulation runs just for extreme events, so-called method of stochasts, have been made operational in
combination with the SIMGRO-model. For each of the stochasts a discrete number of realizations are
defined, which are then combined to events. For each of the model cells the results are evaluated in
terms of inundation depth, yielding cumulative frequency functions.
In detail the following modelling approaches have been implemented at the respective case study sites.
2.1. Grue site, Norway
Some groundwater and leaching simulations have been performed at the Grue site as minor parts of a
previous project surveying pesticide contents in groundwater. To illustrate how washing sites for
pesticide spraying equipment might contaminate neighbouring drinking wells, the pattern of
groundwater flow in a small area around a selected washing site was simulated with Modflow and
ModPath. To illustrate the importance of diffuse pollution from different soils and the different leaching
of different pesticides, MACRO_DB and PRZM have been used for to simulate pesticide leaching from
different soils. Contrasting the holistic perspectives in Genesis, the previous model simulations were
performed to illustrate separate questions and the models have not been coupled, and the leaching
models have not been calibrated and validated against field results from field experiments. The
simulation models and the underlying conceptual models are based on results from soil investigations
and analyses, but have not taken into consideration the impacts of winter climate and local topography.
The approaches, the coupling of models and the field experiments providing data for model calibration
and verifications thus makes the modelling in Genesis clearly different from the previous preliminary
modelling at Grue.
2.2. Caretti site, Italy
At Caretti site the general idea is modeling organic compounds migration from the source to the human
receptors, through GW flow system.
The conceptual model is a multi-aquifer system, where a first shallower aquifer and the 1st confined
regional aquifer are affected by contamination. Source of contamination is located below water table.
Contamination is represented by chlorinated organic compounds, mainly VC, TCE and PCE. The most
dangerous for human health is represented by VC.
43
No numerical model of Caretti site (local scale) has been done until now, because UNIFE is performing a
new detailed characterization of the site (WP2 and WP3).
The needs related to modeling are:

Study the contaminant migration, taking into account biochemical attenuation processes;

Predict migration of contaminants;

Assess the risk for human receptors related to vapours migration through the unsaturated zone.
Missing data include:

Hydraulic connection between aquifers and with direct and lateral recharge (cooperation
started with UFZ in order to analyze environmental isotopes)

transport parameters of the aquifers (WP3);

solutes parameters with respect to transport processes (WP3);

assessment of natural attenuation processes (cooperation started with UFZ in order to assess
the biodegradation rates by means of contaminant isotopes, microbiological essays).
2.3. Murtal aquifer, Austria
The model SIMWASER describes the relation between soil water balance and plant growth depending
on weather, plant and soil characteristics on a daily basis. On top of that the nitrogen and carbon
dynamics within the soil are simulated by the STOTRASIM model. The combination of the two models
allows for the computation of nitrogen leaching beneath so-called hydrotopes which represent a unique
combination of lot cultivation, soil type and soil thickness.
The resulting groundwater recharge and nitrate concentration time series are further used as input
conditions to a transient model of saturated groundwater flow. This output-input coupled model is well
calibrated for a 15 years time period and can be used for scenario calculations of the spatial and
temporal impacts of different land use options on groundwater quantity and quality. The scenarios also
comprise the prediction of extreme events or the impact of climate change effects on the water cycle.
The collected data sets from monolithic high precision lysimeters in combination with groundwater
monitoring results may also be used to validate different sets of unsaturated flow and transport models,
even a model comparison for simulating nitrate leaching can be carried out.
2.4. Feucherolles site, France
Spatial scale of interest is the plot scale. INRA EGC is currently using several approaches to model the
transport of water and solutes through the soil profile.
44
For water transport, HYDRUS_1D and the crop model STICS are combined. HYDRUS_1D is used to get
hydrodynamic parameters by inversion of the field data on water content and water potentials in the
different instrumented plots (i.e. corresponding to the five different treatments 4 organic amendments
and control). STICS is used to get the crop/plant parameters taking into account the dry mass production
and crop yields in each treatment plot. These parameters are used to describe water uptake by the crop
in HYDRUS_1D.
Concerning nitrate, the set of parameters has to be enriched with parameters concerning the dynamics
of organic matter and nitrogen. These data originate from laboratory scale incubation experiments. The
model CANTIS has been used to fit the decomposition of organic matter and N dynamics in the top soil
for the several plots of the field trials. The CANTIS model is integrated as a module in the transport
model PASTIS (PASTIS Model, Prediction of Agricultural Solute Transformations in Soil Monodimensional Transport). PASTIS simulations will be done using the set hydrodynamic and crop
parameters validated with the Br experiment. PASTIS will simulate nitrate losses and balances in each
treatment. Losses of N by leaching concern the amount of N leaving the first 1,2 m of the soil profile.
The simulations will be compared to nitrate balances estimated from measurements in the soil profile
and from crop exportations.
2.5. Zagreb site, Croatia
The general transport modeling approach consists of achieving a better understanding of the transport
regime of heavy metals and quantifying the dominant controlling process. For that purpose the two sites
within the Zagreb aquifer system are chosen, the Stara Loza wellfield and the new Kosnica wellfield
which is still in the planning phase. Since the background values for heavy metals are missing, the
approach where initial conditions are set to zero everywhere in the model domain will be applied.
Data needs exist in the following areas:

Hydraulic conductivity and effective porosity parameters.

Geochemical (heavy metals) maps of topsoil (different scales); horizontal distribution of total
metal contents in the soil surface layer.

Geochemical, mineralogical, sedimentological and pedological data of soil profiles at different
locations
2.6. Vosvozis site, Greece
For the case study of Vosvozis, DUTH uses the following models :

In order to predict surface runoff and nutrient loadings on surface waters, DUTH uses SWAT
model. Thus, it is possible to predict the impact of various land management practices on water,
45
in large complex watersheds with varying soils, land use and management conditions over long
periods of time and to make scenarios related to climate changes.

In order to study flow and contaminant transport in the unsaturated zone, DUTH has installed
on August 2009 three lysimeters on selected sites of the study area. The main purpose of the
lysimeters is to study the flow and contaminant transport in the unsaturated zone and to
determine the actual evapotranspiration in our study site. Results will be used as boundary
condition for the groundwater modelling.
Existing data comprise: Meteorological data from 5 meteorological stations operating in the broader
study area for the last twenty years; Data of three gauging stations at Vosvozis river consisting of biweekly measurements from August 2005 on; Land uses, soil types and the digital elevation model;
Hydrochemical data from 25 irrigation boreholes for the time period 2003 to 2006 (only during irrigation
time); Piezometric data from 25 irrigation boreholes from 1995 on (quaterly measurements).
2.7. Mancha Oriental site, Spain
The developed socio-hydro-economic modelling framework allows selecting sustainable cost-efficient
measures and management strategies to achieve the good quantitative and chemical groundwater
status in an uncertain environment.
Management Model
An optimization model is developed to define efficient fertilizer allocation in agriculture: when, where
and by how much fertilizer reductions have to be applied to meet the ambient standards (groundwater
quality) in specific control sites in the aquifer.
The efficient allocation maximizes the present value of the net social benefit. The net social benefit
equals the benefit received from the use of the resource minus external costs imposed on the society,
including costs of damage from pollutants in the environment. Unless the level of pollution is very high
indeed, the marginal damage caused by a unit of pollution increases with the amount emitted, and the
marginal control cost increases with the amount controlled. Efficiency is achieved when the marginal
cost of control is equal to the marginal damage caused by the pollution for each emitter. Since emissions
are what can be controlled, but the concentration at the receptor cites are the policy targets, it is
necessary to relate both through the proper numerical simulation of the pollutants leaching, transport
and fate within the aquifer.
In the proposed hydro-economic modelling framework, the non-point pollution abatement problem was
stated as the maximization of welfare from crop production subject to constraints that control the
environmental impacts of the decisions in the study region. Welfare was measured as the private net
revenue, calculated through crop production functions and data on crops, nitrogen and water prices.
The hydro-economic model integrates the environmental impact of fertilization by simulation of soil
46
nitrogen dynamics and fate and transport of nitrate in groundwater with the economic impact
(agricultural income losses) of water and fertilization restrictions, assessed through agronomic functions
representing crop yields and crop prices. The decision variables of the problem are the sustainable
quantities of nitrogen per hectare applied in the different crop areas (pollution sources) to meet the
environmental constraints.
Pollutant Concentration Response Matrix
The response matrix describes the influence of pollutant sources upon concentrations at the control
sites over time. The number of columns, n, equals the number of crop areas (pollution sources) times
the number of years within the planning horizon. The number of rows, m, equals the number of control
sites times the number of simulated time steps in the frame of the problem. The simulated time horizon
corresponds to the time for the solute to pass all the control sites, and it is independent of the length of
the planning period.
Agronomic simulation
Crop production and nitrogen leaching functions can be derived from agronomic simulation models like
EPIC. GLEAMS and NLEAP are also popular models for simulating nitrate leaching. In EPIC, a crop growth
/chemical transport simulation model help defines functions relating crop yield, and groundwater
nitrate leaching to water applied, on-ground nitrogen fertilization and nitrogen stock in the soil. These
functions will depend on local conditions on soils, climate, irrigation water, tillage, and other operations.
Data needs and availability
The aforementioned modelling approach requires a large quantity of data related to groundwater
information and also on demands. The groundwater information includes data coming from climatology,
geology, piezometric heads (154 locations with data from 1975 until 2005), recharge/pumping estimates
(remote sensing images + ET model), pumping tests, time series of nitrate concentration and streamflow
measurements. On the other hand, information on demands covers temporal and spatial crop
distribution, crop water requirements (ET), urban water supply demand, fertilizer use, pumping well
spatial distribution, crop prices and farmers cost data.
2.8. Bogucice site, Poland
3D flow and transport model (Visual Modflow Pro, version 4.3) is available for the study area. In the
framework of Genesis project, higher spatial resolution of existing model will be introduced. Also,
improvement of model structure, better characterization of surface water – groundwater interaction
and inclusion of GDE problems is envisaged. After recalibration, the 3D flow and transport regional
model will be useful for groundwater management purposes, better understanding of the system,
better definition of GWD requirements with respect to DWPA and GEPA. Coupling of the climate model
47
(developed by SMHI under WP5) to existing flow and transport model (through fluctuations of the
infiltration rate) will enable prediction water table fluctuations in the study area.
Data availability related to modeling (which is also mostly true for Czestochowa test site): (i) 3D flow and
transport regional model, (ii) environmental tracers, wells discharge, hydraulic heads, (iii) basic climatic
data necessary for climate submodels. Data needed: (i) stream flow measurements (better
characterization of surface water – groundwater interaction), (ii) GW level fluctuations, (iii) stable
isotopes measurements (better characterization of GW –GDE interaction).
2.9. Lule site, Sweden
With the help of groundwater data, obtained from observation wells installed orthogonal to the river
flow, we plan to create a conceptual model. This model is aimed to reconstruct the exchange between
river water and groundwater aquifer through the hyporheic zone. We will be able to identify direction of
water flow through the river bed wall, thus say whether groundwater feed the river or river drains into
the surrounding.
2.10. Po valley site, Italy
Studies are required to understand the role of riparian strip in fontanili status mitigation. The modeling
approach will include (i) development of vertical unsaturated nitrate and pesticide fate model to
groundwater and (ii) development of a lateral groundwater solute flow model to fontanili. Additionally,
the selected models have to allow performing the effect of land use change and of riparian vegetation.
2.11. De Kromme Rijn site, The Netherlands
From previous studies an integrated hydrological model comprising modules for saturated groundwater,
unsaturated soil water and surface waters is available. First attempts of modelling groundwater
pollution by nitrate have been made, but should be elaborated by coupling the ANIMO model to the
MODFLOW based groundwater model. This model linkage should be the basis of pesticide and heavy
metal leaching to groundwater and loading of surface waters.
In order to avoid long computation times short simulation model runs just for the extreme events can be
performed as an alternative. This so-called method of stochasts has been made operational in
combination with the SIMGRO-model. For each of the stochasts a discrete number of realizations are
defined, for instance, 15 possible realizations for the total precipitation, ranging between 50 and 190
mm related to a 9-day period. The associated probabilities are derived from the probability curves
representing 3 climate scenarios. The various realizations of the separate stochasts are then combined
48
to so-called events, which are run through with the SIMGRO model. For each of the model cells the
results are put in ascending order in terms of inundation depth, yielding cumulative frequency functions.
49