Drought Ahead! February 27th, London
Droughts of the future – scenarios and prospects
Steven Wade and Jean-Philippe Vidal HR Wallingford
Acknowledgements •Effects of climate change on river flows and groundwater recharge – CL04 •Climate change and sewerage systems – CL10 •Defra Cross-Regional Research Programme •EA Severe Droughts project •Business Risks of climate change (SNIFFER) •EEA CC indicators •EC COP12 negotiations •EC-India CC research collaboration •HRW company research Page 2
Worst UK rainfall droughts (Vidal and Wade, forthcoming)
1971/2
1995/96 1995 1984
1921
1976 Page 3
Scenarios and prospects – too little or too much? •Future Scenarios • HadRM3/UKCIP02 • UKWIR/EA research • Changes to population & demand
•Prospects for rainfall drought •Prospects for changes in river flow and recharge •Prospects for water resources drought Page 4
Global warming (Forth Assessment Report, 2007)
Page 5
Global warming (Forth Assessment Report, 2007)
Page 6
Changes in precipitation patterns based on HadRM3 (Wade et al., 2006) South East of England Possible changes in precipitation 3 winter months (OND) 450
Total rainfall Oct-Nov-Dec (mm)
400 350 300 250 200 150 100 50 0 1960
1970
Control run 1961-1990 Page 7
1980
1990
2000
2010
Low Emissions
2020
2030
2040
Medium High Emissions
2050
2060
2070
2080
High Emissions
2090
2100
Changes in precipitation patterns based on HadRM3 (Wade et al., 2006) Defra Cross-Regional Climate South East of England change programme Possible changes in precipitation 3 summer months (JAS) 200
Total rainfall July-Aug-Sept (mm)
180 160 140 120 100 80 60 40 20 0 1960
1970
1980
Control run 1961-1990 Page 8
1990
2000
2010
Low Emissions
2020
2030
2040
Medium High Emissions
2050
2060
2070
2080
High Emissions
2090
2100
Jan
Feb
Mar
Changes in rainfall, 2020s
Apr
A2 scenario (UKWIR, 2007)
+ 22 % + 20 %
Mersey, NW England
+ 18 % 50
+ 16 %
40 30
-10 -20 -30
+8%
-40
rin Su g m m e Au r tu m n
in te r
Sp
De c De c
W
O ct N ov O ct N ov
g
p Se
Ju l
Au
ay
Ja n
Ju n
-50
+6%
M
+ 10 %
Ap r
Aug
b
Jul
0
ar
Jun
10
M
May
20
Fe
+ 12 %
Percent change
+ 14 %
+4%
Stour, SE England
+2% 40
0
30
Sep
Oct
Nov
Dec
-4 % -6 % -8 %
Percent change
20
-2 %
10 0 -10 -20 -30
-14 %
Page 9
UKWIR, 2007
rin Su g m m e Au r tu m n
in te r
W
-12 %
Sp
g
p Se
Ju l
Au
Ju n
ay M
Ap r
b
ar M
Fe
Ja n
-40
-10 %
The chance of a dry winter: Test & Itchen rainfall pdf 4.5
x 10
-3
1970s 2020s 2050s 2080s
4 3.5 3 2.5
04/05 & 05/06
2 1.5 1 0.5 0 Page 10
0
200
400
600 800 Precipitation (mm)
1000
1200
The chance of a dry winter: Test & Itchen cdf 1 1970s 2020s 2050s 2080s
0.9 0.8 0.7 0.6 0.5
Wetter winters
0.4 0.3 0.2 0.1 0 Page 11
Wetter 1 in 10 year dry winters No change in 1 in 40+ dry winters? 0
100
200
300
400 500 600 Precipitation (mm)
700
800
900
Future rainfall drought (Vidal and Wade, forthcoming) The number of three month extreme rainfall droughts (SPI3 indicator)
•‘Short’ rainfall droughts likely to increase three-fold
Page 12
Future rainfall drought (Vidal and Wade, forthcoming) The number of twelve month extreme rainfall droughts (SPI12 indicator)
•Little change in longer droughts •Reduction in 12 month rainfall droughts in the North, Scotland and Northern Ireland Page 13
Future rainfall drought (Vidal and Wade, forthcoming) The time spent in each drought class for the SPI3 indicator
Page 14
Future rainfall drought (Vidal and Wade, forthcoming) The time spent in each drought class for the SPI12 indicator
Page 15
Prospects for river flows – role of storage Multi-model, A2 scenario, 2020s (UKWIR, 2006) Tamar@Gunnislake (47001) 50 90% confidence intervals 50% confidence intervals median
40
Change in monthly flows (%)
30 20 10
BFI=46%
0 -10 -20 -30 -40 -50
J
F
M
A
M
J
J
A
S
O
N
D
Itchen@AllbrookHighbridge (42010) 50 90% confidence intervals 50% confidence intervals median
40
Change in monthly flows (%)
30 20 10
BFI=96%
0 -10 -20 -30 -40
Page 16
-50
J
F
M
A
M
J
J
A
S
O
N
D
Average changes in monthly flow for 70 catchments Multi-model, A2 scenario, 2020s (UKWIR, 2007)
Page 17
Page 18
1
29
00
04
04
00
00
8
9
1
2
1
(T 00 ha 3 m es 39 ) 01 6 39 02 0 39 03 7 40 01 1 42 01 410 0 1 (It 1 ch en 43 ) 00 5 47 00 9 48 00 4 52 01 6 53 00 9 54 01 6 54 04 G 0 R 2 ( G 3G R C 3 (3 Ms G ) C M s) AV ER AG E
39 00
28
27
27
26
14
Percent change in annual recharge
Prospects for recharge – little change but longer groundwater recession Multi-model, A2 scenario, 2020s (UKWIR, 2007)
15
10 Rainfall-runoff models GW models
5
0
-5
-10
-15
-20
-25
-30
-35
Entec
Prospects for water resources drought Water futures for the South East (Wade et al., 2006) 2020s Small increase in the demand (2%) for water due to climate change Large increases in demand for water in ‘growth areas’ due to increasing population/households Potential supply-demand deficits of 4 to 15% in the SE. Potential for additional investment ca. £50M per water resources zone in development ‘hot-spots.’
2050s Increase in demand (4%) due to climate change Increases in demand depending on socioeconomic scenario Potential supplydemand deficits of 7 to 32 % in SE
Water Futures: 2080s resource requirements =f(climate change, socio-economic change)
160.0
350.0
140.0
300.0
120.0 100.0 Water Supply Agriculture Environment
60.0 40.0
250.0 200.0 150.0 100.0 50.0
20.0 0.0
Page 19
Requirements Ml/d
Requirements Ml/d
Water Futures: 2050s resource requirements =f(climate change, socio-economic change)
80.0
2080s Further increases in demand due to climate change Overall increases depending on socio-economic scenario Potential supplydemand deficits of 16 to 46% in SE
WMLE
WMHE
NEMHE Scenario
GSLE
GSHE
0.0 WMLE
WMHE
NEMHE Scenario
GSLE
GSHE
Conclusions •The drought 2004/5 to 2006 was the result of several dry winters and low winter recharge •In a warmer climate winters will be wetter and summers drier - dry winters will still occur •Short droughts will increase three-fold (Aut/Sum/Spr) •River flows affected by change in seasonal climate and catchment characteristics – higher flows and recharge will be ‘squeezed’ into a shorter period – longer recessions •Water resources drought affected by WRZ characteristics (storage/licence), changes in demand and how we choose to adapt to climate change Page 20
Example project reports & research papers Vidal, J.P. and Wade, S.D. (2007). A framework for developing highresolution multi-model climate projections: 21st century scenarios for the UK. Int. J. Climatology (accepted). Vidal, J.P. and Wade, S.D. (2007). Multimodel projections of catchment-scale precipitation regime. J. Hydrology (submitted). Vidal, J.P. and Wade, S.D. (2007) Effects of climate change of river flows and groundwater recharge: Guidelines for resources assessments and UKWIR06 scenarios. UKWIR Report 05/CL/04/* Wade, S.D., Barnett, C. and Fenn, T. (2006). Climate change and water resources. Defra Cross-Regional Climate Change Impacts and Adaptation Research Programme: Topic C – Water. Wade, S.D., Jones, P.D. and Osborn, T. (2006). The impacts of climate change on severe droughts. Implications for decision making. Environment Agency Science Report: SC040068/SR3. Page 21
