ClimDev-Africa
Agricultural Water Management
in the Context of Climate Change
Tilahun Amede, Seleshi B. Awlachew, Bancy Matti,
Seydou Traore, Muluneh Yitayew, Zeleke Belay
First Climate Change and Development in Africa (CCDA-I) Conference
Addis Ababa, Ethiopia, 17-19 October 2011
1
CC IMPACTS: RAINFED AGRICULTURE
▪ Climate variability will erode the resources base, and affect
ecosystem services : Recurrent droughts & severe floods;
▪ Droughts will decrease yields / productivity
▪ Floods may damage crops and infrastructure (irrigation, road)
▪ Complicate farm operations abd services;
▪ Fluctuations in farmers’ income: poor farmers may lack
means to buffer extreme years
▪ Impact on national economy, with 90% probability
2
IMPACTS: IRRIGATED AGRICULTURE
▪ Glacier melt of water towers: temporary increase
/ decrease in water reserves;
▪ Changes in groundwater recharge ;
▪ Changes in timing and magnitude of river flows
(irrigation schemes tapping directly from river,
and storage requirements);
▪ Temperature effects on water productivity:
unproductive evaporation;
▪ CO2 fertilization and irrigation productivity:
3
“Over the past Gada, we have lost two
months of rain. Now the rain is not
coming at the right time: it is starting
later and finishing before long. My
daughter is now five years old and she
has not seen a good harvest yet.”
4
Lars Naess, 2009
Annual water balance (A) and water
withdrawal (B) of Africa and implications CC
(UNEP, 2010)
(UNEP, 2005)
Make Choices : Scenarios to 2050
Today
Without productivity
improvements
CA Scenario
Policies for productivity gains, upgrading rainfed,
revitalized irrigation, trade
6
Based on WaterSim analysis for the CA
Upgrade rainfed agriculture
Dependence on green and blue water 2000
7
Climate-smart Rainwater management
systems (RWM)
• Integrated strategy that enables actors to
systematically map, capture, store and efficiently use
Green and Blue water in a landscape for productive
and domestic purposes and ecosystem services.
• Decrease unproductive water losses;
• Improve the water productivity (increase returns per
unit of water investment)
• Capitalizes on harvesting principles, water productivity
at various scales;
• Combining water management with land and
vegetation management.
8
Investing
Investing
in Irrigation
in Irrigation
2.5
320
World Bank lending for
irrigation
2.0
Irrigated Area
280
240
200
1.5
160
1.0
Food price index
120
80
0.5
40
0
0
1960
1965
1970
1975
1980
1985
1990
1995
2000
Dependency effect?
2005
9
Reduce water loss for climate
change adaptation
Average
Canal type
N
flow rate
(l/s)
Loss
(l/s/100m)
% loss
per
100m*
% loss/
100m/30l/s
Main canal
121
43.21a
2.58a
6.46a
4.49b
Secondary canal
57
33.03b
1.59b
4.40b
4.00b
Field canal
49
2.88c
0.39c
2.49c
25.94a
Increased Storage Capacity for CC
adaptation;Comparision
evenofwithout
external support
Per capita Storage Capacity
Per Capita Storage (m^3)
7000
6150
6000
4729
5000
4000
3255
2486
3000
2000
1000
1287
1406
Thailand
Laos
746
4
43
Kenya
Ethiopia
0
South
Africa
China
Brazil
Australia
North
America
Countries
11
F
a
r
m
C
3
2
1
0
2
4
2
1
1
8
1
5
1
2
F
a
r
m
B
4
3
2
1
8
0
0
7
0
6
0
5
0
4
0
1
2
F
a
r
m
A
8
4
0
0
30 N
60N
N
0
30 N
60N
N
0
30 N
60N
N
Zai
Tuber yield (t/ha) Tuber yield (t/ha) Tuber yield (t/ha)
Micro dose
8
0
7
0
6
0
5
0
4
0
3
0
4
C
o
n
t
r
o
l
W
i
t
h
o
u
tZ
a
i
W
i
t
h
Z
a
i
12
Improve Livestock Systems for CC adaptation
▪
▪
▪
▪
▪
▪
▪
Improve feed quality; reduce
methane emissions
Integrate livestock into the wider
development agenda (e.g.
irrigation; watershed
management);
Developing watering points in
closer distances (> 35% milk
yield);
Limit conversion of range to annual
croplands;
Improve animal management
(health, feed quality, productivity);
Interventions to maximize
transpiration at the expense of
evaporation (feed);
Incentives for adaptation (Value
addition/ market opportunities) of
Convert unproductive water to productive use for
CC adaptation
High unproductive water losses = Low system productivity;
Lenche Dima - all cropland
Kuhar Michael - all cropland
3000
1800
1600
2500
1000
livestock
crops
800
600
flows per HH (m3)
1200
2000
livestock
1500
crops
1000
400
500
200
0
deep
percolation
runoff
transpiration
evaporation
deep
percolation
runoff
transpiration
0
evaporation
flows per HH (m3)
1400
14
Building Adaptive capacity on local experiences
..
• Building on byelaws/ religious
organizations/ Water User
Associations
• Facilitate information flow /
technologies using local
channels
• Local institutions for collective
action: Upstream-downstream
• Commitment from local
authorities and policy makers
• Home gardens; women
15
Box 1: Majaluba for Rice
Production in Shinyanga, Tanzania
Box 2. Small scale irrigation in
Ethiopia
▪ In Tanzania, farmers excavated
bunded basins, locally known as
‘majaluba’ which hold rainwater for
supplemental irrigation of crops in
ASAL regions;
▪ About 35% of the rice in TZ is
produced this way under smallholder
farming Shinyanga, Dodoma, Tabora
and the Lake Regions;
▪ Majaluba utilize direct rainfall and
runoff
harvesting
from
external
catchments;
▪ Generally, rice yields are higher,
attaining 3.43 t ha-1 with the use of
harvested water for irrigation as
compared to 2.17 t ha-1 ;
▪ These systems have increased
household incomes by 67%.;
▪ Augment
by
other
storage
infrastructures
SSI in four administrative regions of
Ethiopia,
▪ Crop yield under irrigation was
higher by at least 35% compared to
non-irrigated farms;
▪ Benefits higher in farms where
external inputs (fertilizer, improved
seeds and pesticides) were used;
▪ Farmers replaced low yielding
varieties by high yielding maize
cultivars;
▪ Shifted towards diverse cropping,
up to 10 new marketable crops;
▪ The real challenge: improving
irrigation efficiency, creating local
capacity and collective action with
local communities;
16
Key messages for CC adaptation:
1.
Investing in water storage at landscape and higher
scales (reservoirs, strategic dams, ground water etc..);
2. Policy geared towards climate-sensitive systems
(Agriculture / wetlands / water towers) and vulnerable
communities;
3. Cross-boundary hydrological planning /management;
drought and flood monitoring and information system;
coping strategies;
4. Improving rainwater management systems, from
capturing to efficient utilization and resilience;
17
5. Responsive research system along with resources for
Tilahun Amede
CPWF Nile Basin Leader
t.amede@cgiar.org
A CGIAR Challenge Programme Water for Food (CPWF)
aims to increase water productivity and resilience of
social and ecological systems
Thank you !