Center for Environmental Systems Research - University of Kassel Possible impacts of climate change on water availability – sensitivity anlysis and response surfaces M. Weiß and J. Alcamo
Center for Environmental Systems Research - University of Kassel
Possible impacts of climate change on water availability – sensitivity anlysis and response
surfaces
M. Weiß and J. Alcamo
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
WaterGAP-overview-
• Physiograhic, socio-economic and climate data to model globally current and future water availability and water uses
• The hydrological model calculates daily water balances on a 0.5 x 0.5 degrees grid call basis
• The water use model calculates water withdrawals for the different sectors household, industry (manufacturing and electricity production) and agriculture (livestock and irrigation).
• By comparison of water availability and water use we can calculate various water stress factors on a river basin scale
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Sensitivity analysis and response surfaces
• The European continent is covered by more than 6000 cells at a typical size of about 35 km to 55 km (depending on latitude)
•18 case study river basins selected
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Lule River
Po
ElbeRhine
SeineLoire
Tagus
Douro
Glomma
Thames
Danube
ShannonVistula
KemijokiAngerman
Tiber River
Guadalquivir
Vaenern Goeta
Glo
mm
a
Ke
mijo
ki
Lule
_Riv
er
Vae
nern
_Goe
ta
Ang
erm
an
Sha
nnon
Tha
mes
Elb
e
Rh
ine
Sei
ne
Da
nube
Loi
re
Po
Tag
us
Dou
ro
Gua
dalq
uivi
r
Vis
tula
Tib
er_
Riv
er
0
400
800
1200
-4
0
4
8
12
16
yearly average precip ita tion
yearly average tem perature
[m m /year] [°C ]
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
Sensitivity analysis I
• based on the 1961-1990 climate averages (CRU, New et al., 2000)
• changes in longterm annual temperature averages (-5°C - +5°C)
• and longterm annual precipitation averages (-50% - +100%)
• preliminary analysis of changes in the longterm average river discharge
• preliminary analysis of changes in the longterm average yearly flow regime (monthly mean discharges)
• first studies on impact thresholds
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm average discharges SA I
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm average discharges
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm average discharges
dT=+5°C=const
dT=0°C=const
dP=+100%=const
dP=0%=const
-50 0 50 100
-100
0
100
200
300
400
500
D anube
chan
ge in
dis
char
ge [%
]
change in precipitation [% ]
-5 -4 -3 -2 -1 0 1 2 3 4 5
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10D anube
chan
ge in
dis
cha
rge
[%]
change in tem perature [°C ]
-50 0 50 100
-100
0
100
200
300
400
500
D anube
chan
ge in
dis
cha
rge
[%]
change in precip itation [% ] -5 -4 -3 -2 -1 0 1 2 3 4 5
200
210
220
230
240
250
260D anube
chan
ge in
dis
cha
rge
[%]
change in tem perature [°C ]
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm average discharges
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm average discharges
-100
0
100
200
300
400
500
-50 0 50 100
Lule
chan
ge in
dis
cha
rge
[%]
change in precipitation [% ]
-5 -4 -3 -2 -1 0 1 2 3 4 5
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3Lule
chan
ge in
dis
char
ge [%
]
change in tem perature [°C ]
-50 0 50 100
-100
0
100
200
300
400
500Lule
chan
ge in
dis
cha
rge
[%]
change in precip itation [% ] -5 -4 -3 -2 -1 0 1 2 3 4 5
110
120
130
140
150
160Lule
chan
ge in
dis
cha
rge
[%]
change in tem perature [°C ]
dT=+5°C=const
dT=0°C=const
dP=+100%=const
dP=0%=const
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
In their response, the river
basins can be divided into
the three groups: northern,
central, and southern
European basins
Fig.: RS for northern, central, southern European catchments
Guadalquivir (Southern
Europe)
Danube (Central Europe)
Lule (Northern Europe)
Response of water availability to climate variations
annual variation, longterm average discharges
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm monthly mean dischargesDanube - variation of precipitation at T=const
0
10
20
30
40
50
60
70
80
90
1 2 3 4 5 6 7 8 9 10 11 12
months
lon
g-t
erm
mo
nth
ly a
ve
rag
e
dis
ch
arg
e [
km
³] 0_+100
0_+75
0_+25
0_0
0_-25
0_-50
Danube - variation of temperature at P=const
0
10
20
30
40
50
60
70
80
90
1 2 3 4 5 6 7 8 9 10 11 12
months
lon
g-t
erm
mo
nth
ly a
ve
rag
e
dis
ch
arg
e [
km
³] -5_0
-2_0
0_0
2_0
5_0
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Threshold studies
• competitive uses a) within society itself, i.e. the different sectorsb) society vs. environment.
various operational thresholds, e.g. minimum flows for hydropower
Envrionmental flow, e.g. thresholds based on technical guidance from the EU Water Framework Directive
water stress indicators
return intervalls of extremes, e.g. drought frequencies
• Thresholds are sector-, region- and system-dependent
global water studies
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
Sensitivity analysis II
• based on the 1961-1990 climate averages (CRU TS 2.1, Mitchell and Jones, 2005)
• changes in longterm seasonal temperature averages (JJA) (-3°C - +3°C)
• and longterm seasonal precipitation averages (JJA) (-50% - +50%)
• preliminary analysis of changes the longterm mean summer river discharge
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
seasonal variation, longterm average discharges SA II (JJA)
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Perturbed Physics Experiment
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm average discharge
1990-2010
2080-2100
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Response of water availability to climate variations
annual variation, longterm average discharge
1990-2010
2080-2100
M. Weiß and J. Alcamo WP 6.2 meeting, Helsinki
Points of discussion
• relationship between annual and seasonal climate changes
coupling function
• Interpolation of climate information
• probabilities