Transcript Climate Change in the Nile Basin

Climate Change
in the Nile Basin
(and some implication for water management)
Jaap Kwadijk
Deltares, Netherlands
ERCA, Grenoble, January 27-28, 2010
Facts
Name:
Lead:
Startdate:
Enddate:
Duration:
Budget:
Technical Assistance Services for Lake Nasser
Flood and Drought Control / Integration of
Climate Change Uncertainty and Flooding
Risk (LNFDC / ICC)
Ministry of water resources and Irrigation,
Planning Sector, Nile Forecasting centre
May 7, 2002
November 30, 2005
41 months
EURO 2,406,476
Consultants
WL-LT:
WL-ST:
WREM:
Univ Hull:
Haskoning:
COINS:
HRI:
Astrid Janssen, Rob van de Weert, Jaap Kwadijk
Kees Bons, Henk Ogink, Kees Sloff, Wil van de Krogt,
Ferdinand Diermanse, Nathalie Asselman, Eelco van
Beek.
Aris Georgakakos, Huming Yao (reservoir modelling)
Tim Bellerby, Rizwan Nawaz (Downscaling, System
development)
Rimma Dankova, Ivo Demmers, Harm Jan Raad (Flood
damage assessment, Strategy assessment tool)
Various support studies
Local Scour, 2D hydraulic modelling
Objectives
• Enhance the modelling facilities of the Nile Forecasting
Centre
• Assess of alternatives for the flood and drought
management with respect tot the management of lake
Nasser
• Provide training on climate change and impact
assessment for the Nile basin
• Benefit from inter basin co-operation
Activities Phase 1
River basin modelling
Hydrological modelling
Assessments of changes
Nile basin hydrological characteristics
Length in Km
Longest Rivers of the World
River Name
Drainage Area in 1000
Km2
Drainage Areas of Rivers of the World
River Name
Discharge (BCM)
Main Discharge of Rivers of the World
River Name
Rainfall
(mm/year)
ETo
(mm/year)
2,500
2,000
1,500
1,000
500
0
3,000
2,500
2,000
1,500
1,000
500
Lake Albert
Lake Kyoga
Lake George
Lake Victoria
Lake Edward
Outflow Lake Victoria
60000
50000
40000
30000
20000
10000
19
78
19
76
19
74
19
72
19
70
19
68
19
66
19
64
19
62
19
60
19
58
19
56
0
Sudd swamp
Gains and losses in the Nile Basin
-3.0
12.4
-1.5
50.2
0.0
-12.6
13.5
6.0
20.8
1200
Rainfall
1000
Natural flow
800
600
400
200
0
Aug '80 - Jul '87
Aug '93 - Jul '00
Water Balance
• Total Rainfall on the Basin is about 2100 BCM.
• Annual Yield of the Nile is Estimated as 84
BCM.
• Ratio of the Annual Yield is 5% of the
Potential.
• 80% of the water origins from Ethiopia (Blue
Nile, Atbara, Sobat)
• => How to increase the yield from the White
Nile
Initial Idea:
• Regulation of Equatorial lakes + Drainage of the
Sudd and other Marshes
Merowe Rsv (P)
Main Nile
Khartoum
White Nile
Sennar Rsv
Roseires Rsv
Kashm el Girba Rsv
Blue Nile
Gebal Aulia Rsv
Lake Tana
Machar Swamp
Sudd Swamp
Lake Albert
Lake Victoria
Machar Rsv
Lake Kyoga
Assessments for future changes in the Nile Basin
Annual volumes at Dongola for different precipitation changes
180
160
-20%
-10%
Current
+10%
+20%
140
Discharge (BCM)
120
100
80
60
40
20
0
1988
1989
1990
1991
1992
1993
1994
1995
Base Years
1996
1997
1998
1999
2000
2001
Blue Nile area, climate sensitivity
Rainfall change
- 10%
+ 10%
Outflow change
- 27%
+ 30%
Potential evaporation change
- 10%
+ 10%
Outflow change
-11%
+ 14%
Climate models
Projection of Climate change of the Nile
(downscaling)
Rainfall on the Nile basin for different
models
FAO
CGCM1
ECHAM4
GFDL
HADCM2
NCAR
CSIRO
CCSR
Comparison future rainfall for different
models
Change in rainfall
(m m /year)
ECHAM4
2040-’69
HADCM2
2040-’69
CSIRO
2040-’69
200
100
0
-100
-200
CGCM1
2040-’69
GFDL
2010-’49
NCAR
2010-’49
CCSR
2040-’69
Comparison effects Climate and other
changes
Water savings at Aswan according to climate change and Infra
structure changes
40
ei
ph
as
Jo
e
ng
1
le
ip
ha
M
se
ac
ha
2
rM
ar
sh
Ba
es
hr
El
G
az
al
C
N
_C
AD
AR
M
2
L
FD
G
AM
-4
H
O
-G
IS
EC
H
Jo
ng
l
-60
SI
R
S1
G
C
G
-40
C
SR
C
-20
-G
IS
0
C
BCM/yr
20
Scenario
Potential projects in the Lake Victoria area
Equatorial
Lake basin
projects
Potential projects in the Blue Nile basin
Blue Nile
projects
Plans for future development Egypt
Estimated annual natural inflow into Lake Nasser
based on all current GCM output
Activities Phase 1
BCM / yr
250
200
Low
150
Central
100
High
50
0
base line
2030
2050
2100
Projection Year
Rainfall change DJF Nile head waters
100
Rainfall change JJA Nile head waters
low
40
central
30
20
high
20
0
-20
2030
2050
Year
2100
Change (%)
60
10
low
0
-10
central
2030
2050
2100
high
-20
-30
Year
Rainfall change DJF Nile head waters
100
80
Change (%)
Change (%)
80
60
low
40
central
20
high
0
-20
2030
2050
Year
2100
Activities Phase 1
Rainfall change DJF Nile head waters
100
60
low
40
central
20
high
0
-20
2030
2050
2100
Year
Rainfall change DJF Nile head waters
100
80
Change (%)
Change (%)
80
60
low
40
central
20
high
0
-20
2030
2050
Year
2100
Lake Victoria, climate sensitivity
Rainfall change DJF Nile head waters
100
Change (%)
80
60
low
40
central
20
high
0
-20
2030
2050
Year
2100
Lake Victoria, climate sensitivity
dP
-10%
0
+10%
Outflow
-29%
0
+31%
dEP
-10%
0
+10%
Outflow
-26%
0
+27%
Activities Phase 1
Rainfall change DJF Nile head waters
100
Rainfall change JJA Nile head waters
60
low
40
central
30
20
high
20
0
-20
2030
2050
Year
2100
Change (%)
Change (%)
80
10
low
0
-10
central
2030
2050
-20
-30
Year
2100
high
Blue Nile area, climate sensitivity
Rainfall change JJA Nile head waters
30
Change (%)
20
10
low
0
-10
central
2030
2050
-20
-30
Year
2100
high
Blue Nile area, climate sensitivity
Rainfall change
- 10%
+ 10%
Outflow change
- 27%
+ 30%
Potential evaporation change
- 10%
+ 10%
Outflow change
-11%
+ 14%
Estimated annual natural inflow into Lake Nasser
based on all current GCM output
Activities Phase 1
BCM / yr
250
200
Low
150
Central
100
High
50
0
base line
2030
2050
Projection Year
Rainfall change DJF Nile head waters
100
Change (%)
80
60
low
40
central
20
high
0
-20
2030
2050
Year
2100
2100
Estimated annual natural inflow into Lake Nasser
based on all current GCM output
BCM / yr
250
200
Low
150
Central
100
High
50
0
base line
2030
2050
Projection Year
2100
Population projection
Projected population (million)
180
160
140
120
100
80
60
40
20
0
Egypt
Ethiopia
Eritrea
Sudan
Uganda
Congo
Kenya
Tanzania
2050
2045
2040
2035
2030
2025
2020
2015
2010
2005
2000
1995
1990
Burundi
Rwanda
Conclusions climate changes
• Large parts of the Nile basin are very sensitive to climate
change
• Uncertainties of climate projections are very large, even
direction of change not clear
• Climate change is not necessarily a threat for the water
supply, however the uncertainty is very large.
• In terms of available water per person the effect of
population growth seems to exceed by far any other
development including the effect of climate change
Implications for water management
Standard communication between hydrologist and
water manager on Climate Change and Sea Level Rise
“ You will face a
problem, The Nile
discharge will
change ! “
Hydrologist
Manager
Standard communication between hydrologist and water manager on Climate Change and
Sea Level Rise
“ How much, ..?? “
Hydrologist
manager
Flexibility of water management
25
20
upper estimate
15
central estimate
10
lower estimate
5
0
NotFlexible
Flexible
-5
-10
-15
-20
current
2050
Year
2100
Definition Integrated Water Resources Management
GWP (2000):
• IWRM is a process which promotes the co-ordinated
development and management of water, land and related
resources, in order to maximise the resultant economic and
social welfare in an equitable manner without
compromising the sustainability of vital ecosystems
See: Tec 4 of GWP
Adaptive water resources management:
An extension of this (personal point of view)
natural system
impacts
natural system
demands
socio-economic
system
impacts
natural system
demands
infrastructure
socio-economic
system
laws,
regulations,
management
institutional
system
impacts
natural system
demands
socio-economic
system
integrated
water resources
management
infrastructure
laws,
regulations,
management
institutional
system
Our budget is 1 billion Euro to use for
effects of climate change, please distribute
• Research
• Monitoring flows
• Adaptations in the national water
management systems
• International co-operation
• Legislation
• Adapt socio-economic systems
Some questions to ask related to CC
• Natural system
– Is the current system capable to determine any change?
(Timely adaptation)
– Is the way we design the WM system sufficient to deal
with the changes (Timely adaptation)
– => co-operate on a good meteo-hydro monitoring
system
– => learn to take potential future developments into
account rather than base design on history only
Some questions to ask related to CC
• Socio-economic system
– How dependent are the sectors on water
availability, how flexible can they act if the
volumes becomes more/less
Some questions to ask related to CC
• Institutional development
– Is the co-operation sufficient if we face changes
that cannot be dealt with by one institute
(country) alone
– => confidence building between
institutes/countries
Problems of climate change in IWRM
Climate change is serious and will have large
hydrological effects. However the meaning for
IWRM is limited because:
• Finding a robust strategy is often beyond the
mandate of the water manager
• It is one of the variables, there are other variables
that might be as important (unless the climate
worst cases would be real).
Problems of climate change in IWRM
Some best practice:
– Adapt to more variability
– Do not base design on time series analysis of long
records only.
– Keep the data collection up to date
– …………………
– …………………
Climate change is a blessing ! ; as platform
for co-operation (Confidence building)
•
•
•
•
It will affect everybody
It has potentially huge effects
Not trivial
Nobody is guilty
• => forms a basis for discussion between experts
without political agenda => high potential for
raising confidence between experts as well as
capacity building
Example Climate Change / modelling as a platform
for discussion: Rhine basin studies 1988-2000
• Start of the period:
– data collection: virtually impossible (Except illegally)
– Hydrological real time data exchange: limited,
emergency conditions only
– Co-operation on development of models: none
Example The Rhine basin
•
CHR (1989 -): hydrologic
modelling of the Rhine
•
Kwadijk (1993): hydrologic
model RHINEFLOW
•
NRP-1 (1990 - 1995):
implications of climate
change on runoff and
sediment transport in the
Rhine river
•
NRP-2/CHR (1996-1999):
impacts of climate change on
the Rhine basin and
implications for water
management in the
Netherlands
•
Floods 1993, 1995
Example Climate Change / modelling as a platform
for discussion: Rhine basin studies 1988-2000
• Now:
–
–
–
–
data collection: easy accessible hydro/meteo data base
Hydrological real time data exchange complete
Co-operation on development of flood forcasting
Still not one overall river basin model
IRBM =
Statements
Climate change is not the most important future
development in the Nile basin
Climate change forms an excellent issue for building
confidence between countries of transboundary
river basins