Effects of climate change on UK groundwater resources · 2009. 5. 6. · Few UK groundwater studies (not quality) • Malcolm & Soulsby (2008) – Coastal aquifer in northern Scotland

Effects of climate change on UK groundwater resources

Dr Chris Jackson5th February 2009

Jackson, Meister & PrudhommeModelling the effects of climate change on UK Chalk groundwater resources using an ensemble of global climate modelsSub. Journal of Hydrology

© NERC All rights reserved

Outline

• Effects of climate change on Chalk groundwater resources of central-southern England

• Prediction of groundwater extreme events under climate change - ongoing research under the NERC Flood Risks and Extreme Events (FREE) programme


Some groundwater questions

• What is the potential impact of CC on groundwater recharge?

• How well does groundwater storage perform under CC compared with other forms of water storage?

• What effect will CC have on borehole yields?• How will CC effect natural water quality, e.g. saline

intrusion and small island hydrogeology?• How will CC effect contaminant mobility in the

environment?• How will the frequency, severity and persistence of

groundwater extreme events (droughts and floods) change over the next century?


Few UK groundwater resource studies

• Yusoff, Hiscock & Conway (2002) – East Anglian Chalk• Consistent decrease in recharge during autumn (17 to 35%) –

reduced summer rainfall and increased autumn PE.• Groundwater levels: -0.7m to 0.5m change in GWL

• Younger et al. (2002) – Yorkshire Chalk• Results for 2036-2045: year-round increases in baseflow are likely.• Decreases in river flow were only predicted to occur under the

‘fossil-fuel free energy future’ scenario.

• Holman et al. (2005) – ReGIS• Effect of climate & socio-economic scenarios on water agriculture,

biodiversity, coasts and floodplains.• Without adaptation -> severe flooding, agricultural abandonment


Few UK groundwater studies (not quality)

• Malcolm & Soulsby (2008) – Coastal aquifer in northern Scotland• Scenarios based on broad interpretation of GCM results• Up to 1 m reductions in mean groundwater level.

• Herrera-Pantoja & Hiscock (2008) – 3 sites: Sussex, East Anglia & Scotland • A1F1 scenario (2020s, 2050s, 2080s) – HadCM3 GCM.• Decrease in rainfall by between 3 and 12%• Increase in PE of ~ 70%!• 20% decrease in recharge – Coltishall, East Anglia• 40% decrease in recharge – Gatwick, Sussex


Sources of uncertainty• GCM uncertainty

• Ability of GCMs to reproduce current & predict future climate

• Downscaling uncertainty• Statistical (SDSM, GlimClim,

weather generator)• Dynamical – RCM

• Internal climate variability• Emissions scenario uncertainty• Groundwater / hydrological models

• Structural• Conceptual and process (under

current & future climate) • Parameter (non-uniqueness)• Observed data• Climate transferability


Rowell (2006) Climatic Change


GCM uncertainty – changes in PPTN

UK HADCM3 – 2080s changes[1951-2000] vs [2071-2100]

(30-yr average)

USA NCAR PCM – 2080s changes[1951-2000] vs [2071-2100]

(30-yr average)


Model IPCC-DDC Modelling Group Country Spatial Resolution Acronym Mesh

(Long x Lat) ~ km over

UK CCSM3 NCCCSM National Centre for Atmospheric

Research USA Gaussian

256 x 128 140 x 140

CNRM-CM3

CNCM3 Météo-France / Centre National de Recherches Météorologiques

France Gaussian 128 x 64

280 x 280

CSIRO-Mk3.0

CSMK3 CSIRO Atmospheric Research Australia Gaussian 192 x 96

190 x 220

ECHAM5/ MPI-OM

MPEH5 Max Planck Institute for Meteorology

Germany Gaussian 192 x 96

190 x 220

ECHO-G ECHOG Meteorological Institute of the University of Bonn, KMA meteorological inst., and M & D group

Germany / Korea

Gaussian 96 x 48

375 x 375

GFDL-CM2.0

GFCM20 Geophysical Fluid Dynamics Laboratory

USA Regular 144 x 90

250 x 200

GFDL-CM2.1

GFCM21 Geophysical Fluid Dynamics Laboratory

USA Regular 144 x 90

250 x 200

GISS-ER GIER NASA / Goddard Institute for Space Studies

USA Regular 72 x 46

500 x 390

INM-CM3.0 INCM3 Institute for Numerical Mathematics

Russia Regular 72 x 45

500 x 400

IPSL-CM4 IPCM4 Institut Pierre Simon Laplace France Regular 96 x 72

375 x 250

MIROC3.2 (medres)

MIMR National Institute for Environmental Studies, and Frontier Research Centre for Global Change

Japan Gaussian 128 x 64

280 x 280

PCM NCPCM National Centre for Atmospheric Research

USA Gaussian 128 x 64

280 x 280

UKMO-HADCM3

HADCM3 UK Met. Office UK Regular 96 x 73

375 x 250

• Calculate monthly mean changes in PPTN and temperature between GCM historic (1961-1990) and future (2071-2090) simulations for each GCM

• Adjust historic series of rainfall and PE using these change factors

• Run recharge model

• Run groundwater model

• Compare results

Our approach


Emissions Scenarios


Annual baseflow


Monthly recharge


Ensemble Average Monthly changes: recharge & baseflow


Finch (2000, 2001) Soils on the Lambeth Group

Roberts & Rosier (2005) Shallow Chalk Soils


Intensive Monitoring


Risk from groundwater flooding

Groundwater flooding is the emergence of groundwater at the ground surface away from perennial river channels, or the rising of groundwater into man-made ground, under conditions where the ‘normal’ ranges of groundwater level and groundwater flow are exceeded.


Modelling groundwater flood risk in the Chalk aquifer from future extreme

rainfall events A project funded by NERC under the

Flood Risk from Extreme Events Thematic Programme


Risk from groundwater flooding

• Significant groundwater flooding in 2000/01, 2003 and 2007

• Estimated 1.6M properties at risk in England and Wales (Jacobs, 2004)

• Most vulnerable properties 383,000 located on exposed Chalk aquifer

• Difficulties in estimating return periods– Lack information on occurrence– Paucity of time series data– Complexities of groundwater systems


Brighton – Winter 2000/01

http://www.streetmap.co.uk/newsearch.srf?x=535000&y=105000&z=5&ar=Y&isp=250&ism=10000&searchp=newsearch.srf&mapp=newmap.srf&dn=751http://www.streetmap.co.uk/newsearch.srf?x=525000&y=105000&z=5&ar=Y&isp=250&ism=10000&searchp=newsearch.srf&mapp=newmap.srf&dn=751http://www.streetmap.co.uk/newsearch.srf?x=525000&y=115000&z=5&ar=Y&isp=250&ism=10000&searchp=newsearch.srf&mapp=newmap.srf&dn=751http://www.streetmap.co.uk/newsearch.srf?x=535000&y=115000&z=5&ar=Y&isp=250&ism=10000&searchp=newsearch.srf&mapp=newmap.srf&dn=751


Marlborough & Berkshire Downs


Somme Valley


MotivationGroundwater flooding is an important issuefor the UK, but:

• Understanding of groundwater response under extreme conditions is poor.

• Conventional flood models fail to represent groundwater response; conventional groundwater models fail to represent flooding.

Improved understanding and new modelsfor risk assessment are needed.


Key Research Objectives• To develop an improved conceptual model of the processes

occurring in groundwater flooding in Chalk catchments.

• To develop a methodology for linking existing and new models within an integrated decision support system.

• To undertake case studies to test the conceptual model, investigate system response, and demonstrate the utility of model integration

• To assess the potential for future changes in groundwater flooding frequency using the integrated modelling system and a range of GCM/RCM scenarios.

• To develop and evaluate simpler methods for forecasting and regional assessment of groundwater flood risk.


Antecedent groundwater conditions

Effects of climate change�on UK groundwater resourcesOutlineSlide Number 3Some groundwater questionsSlide Number 5Slide Number 6Sources of uncertaintyRowell (2006) Climatic ChangeGCM uncertainty – changes in PPTNOur approachEmissions ScenariosSlide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Annual baseflowMonthly rechargeEnsemble Average�Monthly changes: recharge & baseflowSlide Number 24Finch (2000, 2001)�Soils on the Lambeth GroupSlide Number 26Intensive MonitoringSlide Number 28Risk from groundwater floodingSlide Number 30Risk from groundwater floodingBrighton – Winter 2000/01Slide Number 33Marlborough & Berkshire DownsMarlborough & Berkshire DownsSomme ValleyMotivationKey Research ObjectivesAntecedent groundwater conditions

Documents

Effects of climate change on UK groundwater resources · 2009. 5. 6. · Few UK groundwater studies (not quality) • Malcolm & Soulsby (2008) – Coastal aquifer in northern Scotland