1. Climate change impacts on groundwater

and dependent ecosystems.Bjørn Kløve a,d,⇑ , Pertti Ala-Aho a , Guillaume Bertrand e , Jason J. Gurdak f , Hans

Kupfersberger g , Jens Kværner d , Timo Muotka b,k , Heikki Mykrä c , Elena Preda h ,

Pekka Rossi a , Cintia Bertacchi Uvo I , Elzie Velasco f , Manuel Pulido-Velazquez j

aUniversity of Oulu, Water Resources and Environmental Engineering Laboratory, 90014

University of Oulu, Finland b University of Oulu, Department of Biology, 90014

University of Oulu, Finland c University of Oulu, Thule Institute, 90014 University of

Oulu, Finland d Bioforsk – Norwegian Institute for Agricultural and Environmental

Research, Frederik A. Dahls vei 20, N-1432 Ås, Norway e Centro de Pesquisas de Água

Subterrânea, Instituto de Geociências, University of São Paulo, Rua do lago 562, Cidade

Universitária, CEP 05508-080, São Paulo, Brazil f Department of Geosciences, San

Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA g

Joanneum Research Forschungsgesellschaft mbH. Elisabethsr. 16/II, A- 8010 Graz,

Austria h University of Bucharest – Splaiul Independentei 91-95, 050095 Bucharest,

Romania I Water Resources Engineering, Lund University, Box 118, 221 00 Lund,

Sweden j Research Institute of Water and Environmental Engineering, Universitat

Politècnica de València, Cami de Vera s/n, 46022 Valencia, Spain k Finnish Environment

Institute, Natural Environment Centre, P.O. Box 413, FI-90014 University of Oulu,

Finland

Summary:

Aquifers and groundwater-dependent ecosystems (GDEs) are facing increasing pressure

from water consumption, irrigation and climate change. These pressures modify

groundwater levels and their temporal patterns and threaten vital ecosystem services

such as arable land irrigation and ecosystem water requirements, especially during

droughts. This review examines climate change effects on groundwater and dependent

ecosystems. The mechanisms affecting natural variability in the global climate and the

consequences of climate and land use changes due to anthropogenic influences are

summarized based on studies from different hydro geological strata and climate zones.

The impacts on ecosystems are discussed based on current findings on factors

influencing the biodiversity and functioning of aquatic and terrestrial ecosystems. The

influence of changes to groundwater on GDE biodiversity and future threats posed by

climate change is reviewed, using information mainly from surface water studies and

knowledge of aquifer and groundwater ecosystems. Several gaps in research are

identified. Due to lack of understanding of several key processes, the uncertainty

associated with management techniques such as numerical modeling is high. The

possibilities and roles of new methodologies such as indicators and modeling methods

are discussed in the context of integrated groundwater resources management.

Examples are provided of management impacts on groundwater, with recommendations

on sustainable management of groundwater.

2. Beneath the surface of global change:

Impacts of climate change on groundwater.

Timothy R. Green a,⇑, Makoto Taniguchi b , Henk Kooi c , Jason J. Gurdak d,1 , Diana M. Allen e, Kevin

M. Hiscock f , Holger Treidel g, Alice Aureli g aUSDA, Agricultural Research Service (ARS), Fort Collins, CO,

USA b Research Institute for Humanity and Nature (RIHN), Kyoto, Japan c VU University, Amsterdam,

The Netherlands d San Francisco State University, CA, USA e Simon Fraser University, Burnaby, BC,

Canada f University of East Anglia, Norwich, UK gUNESCO, International Hydrological Programme (IHP),

Paris, France

Summary:

Global change encompasses changes in the characteristics of inter-related climate

variables in space and time, and derived changes in terrestrial processes, including

human activities that affect the environment. As such, projected global change

includes groundwater systems. Here, groundwater is defined as all subsurface water

including soil water, deeper vidus zone water, and unconfined and confined aquifer

water. Potential effects of climate change combined with land and water

management on surface water have been studied in some details. Equivalent

studies of groundwater systems have lagged behind these advances, but research

and broad interest in projected climate effects on groundwater have been

accelerating in recent years. In this paper, we provide an overview and synthesis of

the key aspects of subsurface hydrology, including water quantity and quality,

related to global change. Adaptation to global change must include sensible

management of groundwater as a renewable, but slow-feedback resource in most

cases. Groundwater storage is already over-tapped in many regions, yet available

subsurface storage may be a key to meeting the combined demands of agriculture,

industry, municipal and domestic water supply, and ecosystems during times of

shortage. The future intensity and frequency of dry periods combined with warming

trends need to be addressed in the context of groundwater resources, even though

projections in space and time are fraught with uncertainty. Finally, potential impacts

of groundwater on the global climate system are largely unknown. Research to

improve our understanding of the joint behaviors of climate and groundwater is

needed, and spin-off benefits on each discipline are likely.

Published by Elsevier B.V.

3. Evaluating the impact of climate change on

groundwater resources in a small

Mediterranean watershed:

Ali Ertürk a , Alpaslan Ekdal b, ⁎, Melike Gürel b , Nusret Karakaya c , Cigdem Guzel d ,

Ethem Gönenç d a Istanbul University, Faculty of Fisheries, Division of Freshwater

Biology, 34470 Laleli, Istanbul, Turkey b Istanbul Technical University, Environmental

Engineering Department, 34469 Maslak, Istanbul, Turkey c Abant İzzet Baysal

University, Environmental Engineering Department, Gölköy Campus, 14280 Bolu, Turkey

d IGEM Research & Consulting Co., Kadıköy, Istanbul, Turkey

Abstract:

Western Mediterranean Region of Turkey is subject to considerable impacts of climate

change that may adversely affect the water resources. Decrease in annual precipitation

and winter precipitation as well as increase in temperatures are observed since 1960s.

In this study, the impact of climate change on groundwater resources in part of

Köyceğiz–Dalyan Watershed was evaluated. Evaluation was done by quantifying the

impacts of climate change on the water budget components. Hydrological modeling was

conducted with SWAT model which was calibrated and validated successfully. Climate

change and land use scenarios were used to calculate the present and future climate

change impacts on water budgets. According to the simulation results, almost all water

budget components have decreased. SWAT was able to allocate less irrigation water

because of the decrease of overall water due to the climate change. This resulted in an

increase of water stressed days and temperature stressed days whereas crop yields

have decreased according to the simulation results. The results indicated that lack of

water is expected to be a problem in the future. In this manner, investigations on

switching to more efficient irrigation methods and to crops with less water consumption

are recommended as adaptation measures to climate change impacts.

4. Simulating the impact of climate change on

the groundwater resources of the Magdalene

Islands, Québec, Canada.

Jean-Michel Lemieuxa,∗ , Jalil Hassaoui a, John Molsona, René Therriena, Pierre

Therriena, Michel Chouteaub, Michel Ouellet c a Département de géologie et de génie

géologique, Université Laval, 1065 avenue de la Médecine, Québec (Québec) G1V 0A6,

Canada b École Polytechnique de Montréal, Département des Génies civil, géologique et

des mines, C.P. 6079 Succursale Centre Ville, Montréal (Québec) H3C 3A7, Canada c

Direction de l’aménagement et des eaux souterraines, Direction générale des politiques

de l’eau, Ministère du Développement durable, de l’Environnement et de la Lutte contre

les changements climatiques, 675, boul. René-Lévesque-Est, 8e étage, bte 42, Québec

(Québec) G1R 5V7, Canada

Abstract:

Study region

This study is conducted in the Magdalen Islands (Québec, Canada), a small archipelago

located in the Gulf of St. Lawrence.

Study focus

This work was undertaken to support the design of a long-term groundwater monitoring

network and for the sustainable management of groundwater resources. This study

relies mostly on the compilation of existing data, but additional field work has also been

carried out, allowing for the first time in the Magdalen Islands, direct observation of the

depth and shape of the transition zone between freshwater and seawater under natural

conditions. Simulations were conducted along a 2D cross-section on Grande Entrée

Island in order to assess the individual and combined impacts of sea-level rise, coastal

erosion and decreased groundwater recharge on the position of the saltwater–

freshwater interface. The simulations were performed considering variable-density flow

and solute transport under saturated-unsaturated conditions. The model was driven by

observed and projected climate change scenarios to 2040 for the Magdalen Islands.

New hydrological insights for the region

The simulation results show that among the three impacts considered, the most

important is sea-level rise, followed by decreasing groundwater recharge and coastal

erosion. When combined, these impacts cause the saltwater–freshwater interface to

migrate inland over a distance of 37 m and to rise by 6.5 m near the coast to 3.1 m

further inland, over a 28-year period.

5. Dynamic Bayesian Networks as a Decision

Support tool for assessing Climate Change

impacts on highly stressed groundwater

systems.

José-Luis Molina a,⇑, David Pulido-Velázquez b , José Luis García-Aróstegui c , Manuel

Pulido-Velázquez d a Salamanca University, High Polytechnic School of Engineering

Avila, Department of Hydraulic Engineering, Av. de los Hornos Caleros, 50, 05003 Ávila,

Spain bGeological Survey of Spain (IGME), Granada Unit, Urb. Alcázar del Genil, 4,

Edificio Zulema, 18006 Granada, Spain

cGeological Survey of Spain (IGME), Murcia Unit, Avda. Miguel de Cervantes, 45 5 A.

Edificio Expo Murcia, 30009 Murcia, Spain dUniversitat Politècnica de València, Research

Institute of Water and Environmental Engineering (IIAMA), Ciudad Politécnica de la

Innovación, Camino de Vera, 46022 Valencia, Spain

Summary:

Bayesian Networks (BNs) are powerful tools for measuring and predicting result of water

management scenarios and unsure drivers like climate change, integrating available

scientific knowledge with the interests of the multiple stakeholders. However, among

their major limitations, the non-transient treatment of the cause-effect relationship

stands out. A Decision Support System (DSS) based on Dynamic Bayesian Networks

(DBNs) is proposed here aimed to mitigate that limitation through time slicing

technique. The DSS comprises several classes (Object-Oriented BN networks), especially

designed for future 5 years length time steps (time slices), covering a total control

period of 30 years (2070–2100). The DSS has been developed for assessing impacts

generated by different Climate Change (CC) scenarios (generated from several Regional

Climatic Models (RCMs) under two emission scenarios, (A1B and A2) in an aquifer

system (Serral-Salinas) affected by intensive groundwater use over the last 30 years. A

calibrated continuous water balance model was used to generate hydrological CC

scenarios, and then a groundwater flow model (MODFLOW) was employed in order to

analyze the aquifer behavior under CC conditions. Results obtained from both models

were used as input for the DSS, considering rainfall, aquifer recharge, variation of

piezometric levels and temporal evolution of aquifer storage as the main hydrological

components of the aquifer system. Results show the evolution of the aquifer storage for

each future time step under different climate change conditions and under controlled

water management interventions. This type of applications would allow establishing

potential adaptation strategies for aquifer systems as the CC comes into effect.

6. Investigating the respective impacts of

groundwater exploitation and climate change

on wetland extension over 150 years.

Antoine Armandine Les Landes a,⇑ , Luc Aquilina a , Jo De Ridder a , Laurent

Longuevergne a , Christian Pagé b , Pascal Goderniaux a,c aGeosciences Rennes – CNRS

– UMR 6118, University of Rennes 1, Bâtiment 14B, Campus Beaulieu, 263, Avenue du

Général Leclerc, 35042 Rennes France b European Center for Research and Advanced

Training in Scientific Computing, 42, Avenue Gaspard Coriolis, Toulouse F-31057 Cedex

1, France cGeology and Applied Geology, University of Mons, 9, Rue de Houdain, B-7000

Mons, Belgium

Summary:

Peat lands are complex ecosystems driven by many physical, chemical, and biological

processes. Peat soils have a significant impact on water quality, ecosystem productivity

and greenhouse gas emissions. However, the extent of peat lands is decreasing across

the world, mainly because of anthropogenic activities such as drainage for agriculture or

groundwater abstractions in underlying aquifers. Potential changes in precipitation and

temperature in the future are likely to apply additional pressure to wetland. In these

circumstances, a methodology for assessing and comparing the respective impacts of

groundwater abstraction and climate change on a groundwater-fed wetland (135 km2)

located in Northwest France is presented. A groundwater model was developed, using

flexible boundary conditions to represent surface–subsurface interactions which allowed

examination of the extent of the wetland areas. This variable parameter is highly

important for land management and is usually not considered in impact studies. The

model was coupled with recharge estimation, groundwater abstraction scenarios, and

climate change scenarios downscaled from 14 GCMs corresponding to the A1B

greenhouse gas (GHG) scenario over the periods 1961–2000 and 2081–2100. Results

show that climate change is expected to have an important impact and reduce the

surface of wetlands by 5.3–13.6%. In comparison, the impact of groundwater

abstraction (100% increases in the expected scenarios) would lead to a maximum

decrease of 3.7%. Results also show that the impacts of climate change and

groundwater abstraction could be partially mitigated by decreasing or stopping land

drainage in specific parts of the area. Water management will require an appropriate

compromise which encompasses ecosystem preservation, economic and public domain

activities.

7. Climate change impacts on groundwater

and soil temperatures in cold and temperate

regions: Implications, mathematical theory, and

emerging simulation tools.

Barret L. Kurylyk a, , Kerry T.B. MacQuarrie a , Jeffrey M. McKenzie b a Department of

Civil Engineering, University of New Brunswick, PO Box 4400, Fredericton, NB E3B 5A3,

Canada b Earth and Planetary Sciences Department, McGill University, 3450 University

Street, Montreal, QC H3A 0E8, Canada

Abstract:

Climate change is expected to increase regional and global air temperatures and

significantly modify precipitation regimes. These projected changes in meteorological

conditions will likely influence subsurface thermal regimes. Increases in groundwater

and soil temperatures could impact groundwater quality, harm groundwater-sourced

ecosystems, and contribute to the geotechnical failure of critical infrastructure.

Furthermore, permafrost thaw induced by rising subsurface temperatures will likely

change surface and subsurface hydrology in high altitude and/or latitude regions and

exacerbate the rate of anthropogenic climate change by releasing stored carbon into

the atmosphere. This contribution discusses the theory and development of subsurface

heat transport equations for cold and temperate regions. Analytical solutions to

transient forms of the conduction equation and the conduction–advection equation with

and without freezing are detailed. In addition, recently developed groundwater flow and

heat transport models that can accommodate freezing and thawing processes are

briefly summarized. These models can be applied to simulate climate change-induced

permafrost degradation and dormant aquifer activation in cold regions. Several previous

reviews have focused on the impact of climate change on subsurface hydraulic regimes

and groundwater resources, but this is the first synthesis of studies considering the

influence of future climate change on subsurface thermal regimes in cold and

temperate regions. The current gaps in this body of knowledge are highlighted, and

recommendations are made for improving future studies by linking atmospheric global

climate models to subsurface heat transport models that consider heat advection via

groundwater flow.

8. Potential climate change impacts on

groundwater resources of south-western

Australia.

Riasat Ali a,⇑ , Don McFarlane a , Sunil Varma b , Warrick Dawes a , Irina

Emelyanova a , Geoff Hodgson a Steve Charles a .a CSIRO Floreat Laboratories, Private

Bag 5, Wembley, WA 6913, Australia b CSIRO Earth Science and Resource Engineering,

26 Dick Parry Avenue, Kensington, WA 6151, Australia

Summary:

About three – quarters of all water used in the south-western Australia is from

groundwater. A decline in rainfall since about 1975 and increased abstraction has

resulted in some groundwater levels declining and groundwater dependent ecosystems

decreasing in health and extent. Levels are rising under some areas used for dry land

(rain fed) agriculture because crops and pastures are shallow rooted. Almost all global

climate models (GCMs) project a drier and hotter climate for the region by 2030. In this

project, five climate scenarios were applied to groundwater models to estimate

groundwater levels in the region in 2030. The climate scenarios were (i) a continuation

of the historical climate of 1975–2007; (ii) a continuation of the more recent climate of

1997–2007 until 2030; and (iii–v) three climate scenarios derived by applying the GCM

projected climate under three global warming scenarios of 0.7, 1.0 and 1.3 °C by 2030.

A sixth scenario considered increasing abstraction levels to maximum allowed levels

under a median future climate (1.0 °C warming). Groundwater levels were found to be

much less affected than surface water resources by a future drier climate as well as for

a continuation of the climate experienced since 1975. For a fixed rainfall, recharge was

highest where soils were sandy, there was little or no perennial vegetation and the

water table was neither very shallow nor very deep. A feature of the project area is that

about half has a water table within 10 m of the soil surface, and about a quarter within

3 m. Levels were not as affected by a decline in rainfall when reduced groundwater

drainage and evapotranspiration losses offset the reduced rainfall amounts. However

once a threshold groundwater level is exceeded, the rainfall fails to refill the available

seasonal storage and groundwater levels decline. Projected water tables declined in all

areas under a drier climate where perennial vegetation was present and able to

intercept recharge or use groundwater directly. In areas under dry land agriculture,

projected groundwater levels continue to rise even under a drier future climate. The

climate change effects on confined groundwater systems are expected to be modest.

This is due to the longer times required for the changed recharge and water level

conditions in the overlying aquifers to propagate to the confined aquifers. All water

balance components are projected to be impacted by climate change to a greater or

lesser extent. This has consequences for the amount of extractable water from both the

unconfined and confined aquifers, changes the risk of sea-water intrusion, and has

implications for the groundwater dependent ecosystems.

9. A review of the impact of climate change on

future nitrate concentrations in groundwater of

the UK .

M.E. Stuart ⁎, D.C. Gooddy, J.P. Bloomfield, A.T. Williams British Geological Survey,

Maclean Building, Wallingford, Oxon, OX10 8BB, UK

Abstract:

This paper reviews the potential impacts of climate change on nitrate concentrations in

groundwater of the UK using a Source–Pathway–Receptor framework. Changes in

temperature, precipitation quantity and distribution, and atmospheric carbon dioxide

concentrations will affect the agricultural nitrate source term through changes in both

soil processes and agricultural productivity. Non-agricultural source terms, such as

urban areas and atmospheric deposition, are also expected to be affected. The

implications for the rate of nitrate leaching to groundwater as a result of these changes

are not yet fully understood but predictions suggest that leaching rate may increase

under future climate scenarios. Climate change will affect the hydrological cycle with

changes to recharge, groundwater levels and resources and flow processes. These

changes will impact on concentrations of nitrate in abstracted water and other

receptors, such as surface water and groundwater-fed wetlands. The implications for

nitrate leaching to groundwater as a result of climate changes are not yet well enough

understood to be able to make useful predictions without more site-specific data. The

few studies which address the whole cycle show likely changes in nitrate leaching

ranging from limited increases to a possible doubling of aquifer concentrations by 2100.

These changes may be masked by nitrate reductions from improved agricultural

practices, but a range of adaption measures need to be identified. Future impact may

also be driven by economic responses to climate change.

10. Climate change impact assessment in

Veneto and Friuli Plain groundwater. Part II: A

spatially resolved regional risk assessment.

S. Pasini a , S. Torresan a , J. Rizzi a, A. Zabeo b, A. Critto a,b,⁎, A. Marcomini b a Centro Euro-

Mediterraneo per i Cambiamenti Climatici (CMCC), Impacts on Soil and Coast Division (ISC), Via Augusto

Imperatore 16, 73100 Lecce, Italy b Department of Environmental Sciences, Informatics and Statistics,

University Ca' Foscari Venice, Calle Larga S. Marta 2137, I-30123 Venice, Italy

Abstract:

Climate change impact assessment on water resources has received high international attention over

the last two decades, due to the observed global warming and its consequences at the global to local

scale. In particular, climate-related risks for groundwater and related ecosystems pose a great concern

to scientists and water authorities involved in the protection of these valuable resources. The close link

of global warming with water cycle alterations encourages research to deepen current knowledge on

relationships between climate trends and status of water systems, and to develop predictive tools for

their sustainable management, copying with key principles of EU water policy. Within the European

project Life+ TRUST (Tool for Regional-scale assessment of groundwater Storage improvement in

adaptation to climate change), a Regional Risk Assessment (RRA) methodology was developed in order

to identify impacts from climate change on groundwater and associated ecosystems (e.g. surface

waters, agricultural areas, natural environments) and to rank areas and receptors at risk in the high and

middle Veneto and Friuli Plain (Italy). Based on an integrated analysis of impacts, vulnerability and risks

linked to climate change at the regional scale, a RRA framework complying with the Sources– Pathway–

Receptor–Consequence (SPRC) approach was defined. Relevant impacts on groundwater and surface

waters (i.e. groundwater level variations, changes in nitrate infiltration processes, changes in water

availability for irrigation) were selected and analyzed through hazard scenario, exposure, susceptibility

and risk assessment. The RRA methodology used hazard scenarios constructed through global and high

resolution model simulations for the 2071–2100 periods, according to IPCC A1B emission scenario in

order to produce useful indications for future risk prioritization and to support the addressing of

adaptation measures, primarily Managed Artificial Recharge (MAR) techniques. Relevant outcomes from

the described RRA application highlighted that potential climate change impacts will occur with different

extension and magnitude in the case study area. Particularly, qualitative and quantitative impacts on

groundwater will occur with more severe consequences in the wettest and in the driest scenario

(respectively). Moreover, such impacts will likely have little direct effects on related ecosystems

croplands, forests and natural environments – lying along the spring area (about 12% of croplands and

2% of natural environments at risk) while more severe consequences will indirectly occur on natural and

anthropic systems through the reduction in quality and quantity of water availability for agricultural and

other uses (about 80% of agricultural areas and 27% of groundwater bodies at risk). © 2012 Elsevier B.V.

All rights reserved.

11. Climate change impacts on water yields

and demands in south-western Australia.

Don McFarlane a,⇑ , Roy Stone b, Sasha Martens c , Jonathan Thomas d , Richard Silberstein a , Riasat Ali

a , Geoff Hodgson a a CSIRO Water for a Healthy Country Flagship, Private Bag 5, Wembley 6913,

Australia B Department of Water, PO Box K822, Perth, Western Australia 6842, Australia

c Jim Davies and Associates, 27 York Street, Subiaco, Western Australia 6008, Australia

d Resource Economics Unit, 15A Rosser Street, Cottesloe, Western Australia 6011, Australia

Summary:

A climate shift in the mid 1970s reduced rainfalls in south-western Australia by 10–15% and inflows into

Reservoirs that supply the city of Perth (population 1.8 m) by more than half. The region has a

Mediterranean climate, similar to other areas in the world experiencing reductions in rainfall and rises in

temperatures. Rainfall–runoff modeling has indicated that stream flows may reduce by a further quarter

by 2030 or by half if a dry future climate is experienced. Groundwater levels on the coastal plain in

south-western Australia have fallen since the mid 1970s where unconfined aquifers are covered with

perennial vegetation, including under the main water supply aquifer for Perth. Modeled projections are

that groundwater levels in most areas will continue to fall through to 2030 under most future climate

scenarios. Projected stream flows and groundwater levels indicate reduced water availability but these

need to be converted to projected water yields, i.e. the amount of water that can be diverted for

consumptive use. This paper reports how projections of future stream flow and groundwater levels were

used to estimate 2030 divertible water yields for a 62,500 km2 area in south-western Australia. These

yields were then compared with estimates of water demands in 2030 to identify areas of water surplus

and deficit under clearly defined assumptions. The methods used to define future yields are based on

sets of rules that could be varied by water managers if desired. Surface water yields are estimated to

decrease by about 24% (possible range of 4% to 49%) which is similar to the projected reduction in

runoff (25% with a range of 7% to 42%). Groundwater yields are projected to fall by only about 2%

(range of +2% to 7%) because of reductions in evapotranspiration and drainage losses as water tables

fall where groundwater levels are close to the surface. In addition, recharge remains relatively high

under cleared areas used for non-irrigated agriculture. In some areas with high groundwater recharge

and little groundwater use groundwater levels may continue to rise even under a hotter and drier future

climate. While overall groundwater yields may be little affected there are very important groundwater

resources, especially those covered by perennial vegetation, which will experience large reductions in

available yield under most projected future climates . Under current per-capita water consumption

levels, rapid population and economic growth, along with the reductions in water yields, are expected to

result in appreciable water deficits developing near Perth and some regional cities in south-western

Australia by 2030. Where both surface water and groundwater resources are available for use,

groundwater is anticipated to become increasingly used in future. Crown Copyright 2012 Published by

Elsevier B.V. All rights reserved.

12. Climate change impact assessment on

Veneto and Friuli plain groundwater. Part I: An

integrated modeling approach for hazard

scenario construction.

F. Baruffi a,1 , A. Cisotto a,1 , A. Cimolino a,1 , M. Ferri a,1 , M. Monego a,1 , D. Norbiato a,1 , M.

Cappelletto a,1 , M. Bisaglia a,1 , A. Pretner b,2 , A. Galli b,2 , A. Scarinci b,2 , V. Marsala b,2 , C. Panelli

b,2 , S. Gualdi c , E. Bucchignani c , S. Torresan c , S. Pasini c,d , A. Critto c,d , A. Marcomini c,d, ⁎ a

Autorità di Bacino dei Fiumi dell'Alto Adriatico, Cannaregio 4314, 30121 Venice, Italy b SGI Studio Galli

Ingegneria, via della Provvidenza 13, 35030 Sarmeola di Rubano (PD), Italy , c Centro Euro-Mediterraneo

per i Cambiamenti Climatici (CMCC), via Augusto Imperatore 16, 73100 Lecce, Italy , d Department of

Environmental Sciences, Informatics and Statistics, University Ca' Foscari Venice, Calle Larga S. Marta

2137, 30123 Venice, Italy

Abstract:Climate change impacts on water resources, particularly groundwater, is a highly debated topic

worldwide, triggering international attention and interest from both researchers and policy makers due

to its relevant link with European water policy directives (e.g. 2000/60/EC and 2007/118/EC) and related

environmental objectives. The understanding of long-term impacts of climate variability and change is

therefore a key challenge in order to address effective protection measures and to implement

sustainable management of water resources. This paper presents the modeling approach adopted

within the Life+ project TRUST (Tool for Regional-scale assessment of groundwater Storage

improvement in adaptation to climate change) in order to provide climate change hazard scenarios for

the shallow groundwater of high Veneto and Friuli Plain, Northern Italy.

Given the aim to evaluate potential impacts on water quantity and quality (e.g. groundwater level

variation, decrease of water availability for irrigation, variations of nitrate infiltration processes), the

modeling approach integrated an ensemble of climate, hydrologic and hydro geologic models running

from the global to the regional scale. Global and regional climate models and downscaling techniques

were used to make climate simulations for the reference period 1961–1990 and the projection period

2010–2100. The simulation of the recent climate was performed using observed radioactive forcing,

whereas the projections have been done prescribing the radioactive forcing according to the IPCC A1B

emission scenario. The climate simulations and the downscaling, then, provided the precipitation,

temperatures and evapo-transpiration fields used for the impact analysis. Based on downscaled climate

projections, 3 reference scenarios for the period 2071–2100 (i.e. the driest, the wettest and the mild

year) were selected and used to run a regional geomorphic climatic and hydro geological model. The

final output of the model ensemble produced information about the potential variations of the water

balance components (e.g. river discharge, groundwater level and volume) due to climate change. Such

projections were used to develop potential hazard scenarios for the case study area, to be further

applied within climate change risk assessment studies for groundwater resources and associated

ecosystems.

Science of the Total Environment 440 (2012) 154–166 Corresponding author at: Dept. of Environmental

Sciences Informatics and Statistics, University Ca' Foscari Venice, Italy. Tel.: +39 041 2348548; fax: +39

041 2348584. E-mail addresses: segreteria@adbve.it (A. Cisotto), andrea.scarinci@sgi-spa.it (A. Scarinci),

silvio.gualdi@bo.ingv.it (S. Gualdi), e.bucchignani@cira.it (E. Bucchignani),

torresan@cmcc.it (S. Torresan), sara.pasini@stud.unive.it (S. Pasini), critto@unive.it (A. Critto),

marcom@unive.it (A. Marcomini). 1 Tel.: +39 041 714444 714343; fax: +39 041 714313. 2 Tel.: +39 049

8976 844; fax: +39 049 8976 784. 0048-9697/$ – see front matter © 2012 Elsevier B.V. All rights

reserved. http://dx.doi.org/10.1016/j.scitotenv.2012.07.070 Contents lists available at SciVerse

ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv

13. Seasonal variation of high elevation

groundwater recharge as indicator of climate

response.

Daniel C. Segal a,⇑ , Jean E. Moran a , Ate Visser b , Michael J. Singleton b , Bradley K. Esser b

a California State University, East Bay, Hayward, CA, United States

b Lawrence Livermore National Laboratory, Livermore, CA, United States

Summary:

High elevation groundwater basins in the western United States are facing changes in the amount and

Timing of snowmelt due to climate change. The objective of this study is to examine seasonal variability

in a high elevation aquifer (Martis Valley Watershed near Truckee, CA) by analyzing (1) tritium and

helium isotopes to determine groundwater sources and age, (2) dissolved noble gases to determine

recharge temperatures and excess air concentrations. Recharge temperatures calculated at pressures

corresponding to well head elevations are similar to mean annual air temperatures at lower elevations

of the watershed, suggesting that most recharge is occurring at these elevations, after equilibrating in

the vadose zone. The groundwater flow depth required to increase the water temperature from the

recharge temperature to the discharge temperature was calculated for each well assuming a typical

geothermal gradient. Groundwater samples contain large amounts of excess helium from terrigenic

sources, including mantle helium and radiogenic helium. Terrigenic helium and tritium concentrations

are used to determine the amount of mixing between the younger and older groundwater sources.

Many of the wells sampled show a mix of groundwater ages ranging from >1000s of years old to

groundwater with tritium concentrations that are in agreement with tritium in modern day

precipitation. Higher seasonal variability found in wells with younger groundwater and shallower flow

depths indicates that the recent recharge most vulnerable to climate impacts helps to supplement the

older, less sustainable waters in the aquifer during periods of increased production.

2014 Elsevier B.V. All rights reserved.

14. Statistical and numerical analyses of the influence

of climate variability on aquifer water levels and

groundwater temperatures: The impacts of climate

change on aquifer thermal regimes.Luminda Niroshana Gunawardhana , So Kazama , Department of Civil Engineering, Tohoku University, 6-

6-06, Aramaki aza aoba, Aoba ku, Sendai, 980-8579, Japan

Abstract:

In this study, we aimed to assess the magnitude of hydro geological alternations, specifically those

changes in the aquifer thermal regime, that are associated with climate change in the Sendai Plain,

Japan. Five General Circulation Models (GCMs), HADCM3, MIROC, ECHAM5, CSIRO and CCSM3, and

three greenhouse gas emission scenarios, A2, A1B and B1, were linked with the meso scale climate using

a statistical downscaling technique to produce a range of plausible future scenarios. Time series analyses

of water level records at different aquifer depths at different observation points suggested that the

vertical groundwater recharge was more predominant than the horizontal water flow. To simulate the

heat transport in the subsurface layers, a model was constructed using the U.S. Geological Survey's

numerical code for energy transport in variably saturated porous media (VS2DH). Water levels in

shallow and deep aquifers were simulated using the Predefined Impulse Response Function in

Continuous Time (PIRFICT) modeling method. The accuracy of the model parameters was assessed by

comparing the simulated water levels to observations at a middle depth in the aquifer. All water level

simulations from the PIRFICT method and the VS2DH numerical model agreed with the observed water

level records, with R2 adj= 62–91% and RMSE= 0.031–0.188 m. Based on our results, the Sendai area

may be warmed by a range of 1.3–4.7 °C (2.66 °C, 2.87 °C and 3.89 °C for 25%, 50% and 75% percentiles,

Respectively) during the 2060–2099 time period, compared to the observed averages between 1967–

2006. The future annual precipitation projections averaged over the same time period ranged from −1%

to 30% (85, 164 and 219 mm/year for 25%, 50% and 75% percentiles, respectively) compared to

observations from 1967–2006. When the effects of all model scenarios were considered, aquifers in the

Sendai Plain may be warmed by a range of 1.0–4.28 °C (0.61–4.59 °C with various uncertainties) at 8 m

of depth from the ground's surface compared to 2007 observations. Additionally, climate change effects

will expand into deeper aquifer depths, but the impacts will vary according to the transient change of

ground surface temperature and changes in ground water recharge rates. The use of 15 GCM scenarios

in our study projected the impacts of a changing climate on the aquifer thermal regime in a reliable

range, which may have a critical impact on groundwater-dominated ecosystems.

© 2012 Elsevier B.V. All rights reserved.

15. Impact of climate change on groundwater

recharge in dry areas: An ecohydrology

approach.

Hui-Hai Liu

Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States

Summary:

This work proposes an ecohydrology-based approach to study the impact of climate change on

groundwater recharge in dry areas. It is largely based on a concept that in dry areas, vegetation

community can be divided into two different groups, shallow- and deep-rooted vegetation, with the

growing-season average of root-zone soil water saturation tending to be at its optimum value for the

growth of deep-rooted vegetation. The concept is supported by data sets collected from different dry

areas. Analytical results of soil water dynamics developed in previous studies are adapted here for

investigating the impact of climate change. Because the conceptual model allows deep-zone soil–water

saturation, averaged over growing seasons, to remain fixed during different climate conditions, we can

construct a relationship among groundwater recharge, the coverage of deep-rooted vegetation, and

climate. As an illustrative example, we apply the developed approach to the Yucca Mountain area. Our

estimated recharge value under the current climate and the vegetation coverage is generally consistent

with results estimated from other methods or observed from the site. We also evaluate how the

recharge will change under several assumed future climate scenarios. The results show that both

groundwater recharge and deep-rooted vegetation coverage increase with decreasing rainfall frequency

(for a given amount of annual rainfall), with increasing average rainfall depth per rainfall event (for a

fixed frequency) and with increasing frequency (for a fixed rainfall depth per rainfall event). The latter

indicates a relatively large degree of buffering effects of vegetation on changes in groundwater

recharge.

2011 Elsevier B.V. All rights reserved.