1. FUTURE OF WATER AND AGRICULTURE IN SRI LANKA IN THE
FACE OF CLIMATE CHANGE
Nishadi Eriyagama & Vladimir Smakhtin (IWMI)
GWP Workshop on Climate Change Food and Water Security
Colombo, Sri Lanka, February 2011
Water for a food-secure world

2. OUTLINE
• Climate change signals in Sri Lanka – observed changes
• What will the future hold? – projected changes
• Impacts
– On water resources
Food Security
– On agriculture
• Climate change vulnerability hotspots?
• Responding to climatic changes
• Knowledge gaps
Water for a food-secure world

3. INFORMATION SOURCES
Interviews and e-mail correspondence with
-Government officials
16
-International experts
Over 75 national and global climate change studies
Sources
IWMI climate change vulnerability mapping
Preliminary review of recent floods
Water for a food-secure world

4. OBSERVED CHANGES
Temperature Rainfall
Warming trends (0C/year) No significant change in Mean
1961-2000 Annual Rainfall Amount
North-East
Monsoon (Dec
– Feb):
Dry Zone reduced &
Anuradhapura variability
0.024-0.026 increased
(Maha)
Intermediate Zone
Badulla
0.022-0.024 Wet Zone
South-West Monsoon
(May – Sept): Stable
(Yala)
Source: Zubair et al. 2005
Water for a food-secure world

5. PROJECTED CHANGES - 1
Temperature
• General consensus: increasingly warmer in 21st century
• IPCC: stronger warming than the global mean in South Asia
• Projected magnitude of change: differs from study to study
Source Model Scenario Base Year Change at end
21st century
Cruz et al. AOGCM A1F1, B1 1961-1990 + 2.93-5.44 0C
2007
Kumar et al. Regional A2, B2 1961-1990 + 2-4 0C
2006; Islam Climate
and Rehman Model-RCM
2004
Basnayake et Statistical A1F1, B1, 1961-1990 + 0.9-3 0C
al. 2004; De Downscaling A2, B2
Silva 2006 of GCMs
Water for a food-secure world

6. PROJECTED CHANGES - 2
Rainfall - Projections for this century confusing and contradictory!
Mean Annual Rainfall
Higher Mean Annual Rainfall Lower Mean Annual Rainfall
Higher South-West Higher South-West Lower South-West
Monsoon R/F Monson R/F Monsoon R/F
Higher North-East Lower North-East Lower North-East
Monsoon R/F Monson R/F Monsoon R/F
Kumar et al 2006; Islam Cruz et al. 2007; De Silva Ashfaq et al. 2009;
and Rehman 2004; 2006; Basnayake and Basnayake et al. 2004
Basnayake et al. 2004; Vithanage 2004b
Basnayake and Vithanage
2004 a
Increased Variability Increased Floods & Droughts
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7. PROJECTED CHANGES - 3
Spatial Pattern of Rainfall Projections for 2050s
Projection 1 Projection 2 Projection 3
+ De Silva, 2006
-- - De Silva, 2006
+
+ --
+ +
Dry Zone + - Dry Zone Dry Zone
+
+
+
+
+ -- - + -- -
+ +
Intermediate Zone + Intermediate Zone + Intermediate Zone
+
Wet Zone + --
Wet Zone Wet Zone--
+ +
++ + + + - ++ -
Basnayake et al. 2004 De Silva 2006 Punyawardane et al. 2010
Ambiguity!
Water for a food-secure world

8. IMPACTS ON WATER RESOURCES
• Dominant School of Thought: Gain in Mean Annual
Water Availability
• But increased temporal and spatial variability
Dry Zone
• Brunt of impact on north eastern and eastern dry
zone: May become even drier!
• Increase in Soil Moisture Defecit in the Dry and
Intermediate zones by 2050 (De Silva 2006): More Intermediate Zone
irrigation? Wet Zone
• Lower water availability in the upper Mahaweli
watershed by 2025 (Shantha & Jayasundera 2005):
More power cuts?
No comprehensive national study!
Water for a food-secure world

9. IMPACTS ON AGRICULTURE
Paddy Tea Coconut
Yield: Yield: Yield:
• 0.1-0.5 0C temp increase: • 100 mm monthly R/F • Production after 2040:
1.2 to 5.9% reduction reduction: 30-80 kg not sufficient for local
(Vidanage & reduction in ‘made’ tea/ha consumption
Abeygunawardena 1994) • Increase in ambient CO2 •Increased pest and
• Temp increase + CO2 concentration to 600 ppm: disease problems -
increase: 24-39% increase 33-37% increase reduce yield (Peiris et al.
(De Costa et al. 2006) (Wijeratne et al. 2007) 2004)
Irrigation Requirement: Spatial Impact: Economy:
13-23% increase in Maha by • Cultivations at low and Losses in the range $32 -
2050 (De Silva 2006) mid elevations more $73 million (Fernando et.
vulnerable (Wijeratne et al 2007)
al. 2007)
Economy: Rs. -11 billion to Rs. +39 billion
by 2100 (Seo et. Al. 2005)
Water for a food-secure world

10. CLIMATE CHANGE VULNERABILITY HOTSPOTS-1
Exposure Index
Anuradhapura
Nuwara-Eliya
Sensitivity Index
Ratnapura
Adaptive Capacity Climate Change Vulnerability
Index Index
Water for a food-secure world

11. CLIMATE CHANGE VULNERABILITY HOTSPOTS -2
Exposure Index based on: Sensitivity Index based on: Population Adaptive Capacity Index
Frequency of exposure to density, % employed in agriculture, based on: education level,
historical droughts, floods, irrigation water availability, agricultural poverty incidence, level of
cyclones diversity (crops diversity, livestock infrastructure development
farming, fishing)
0 – lowest vulnerability 100 – highest vulnerability
Water for a food-secure world

12. CLIMATE CHANGE VULNERABILITY HOTSPOTS -3
Highly vulnerable areas are:
• Typical farming areas
• Have low socioeconomic and infrastructural
assets (low adaptive capacity) Anuradhapura
• Show high levels of exposure to historical
climate extremes Nuwara-Eliya
Ratnapura
• Primary food producing areas - rely heavily on
water availability for agriculture
Water for a food-secure world

13. RESPONDING TO CLIMATIC CHANGES - 1
Response
Mitigation Adaptation
Knowledge
•Signatory to UNFCC •National Adaptation
and Kyoto Protocol Strategy
•Second National •“No Regrets”
Communication interventions
prepared
Research Eg: Restoration of the
•Small hydropower ancient tank system
CDM projects
•Others – “Green
Lanka” program
Water for a food-secure world

14. RESPONDING TO CLIMATIC CHANGES - 2
Adaptation
Crops Climate Tools Water Resources Sea Level Rise
•Development of •Predicting annual •Restoring existing •Climate Change
heat/salt/pest national coconut tanks Adaptation Action
resistant short term production Plan by Coast
crop varieties by 6 •Developing sustainable Conservation
research institutes. •Predicting seasonal groundwater Department (CCD)
eg. Rice Research and water availability •Rainwater harvesting
Development within the Mahaweli and storage
Institute (RRDI) scheme
•Use of micro-irrigation
•Crop diversification,
change of planting •Wastewater reuse
time and location •Greater shift towards
alternative energy from
hydropower
Water for a food-secure world

15. KNOWLEDGE GAPS
• Detailed and quality controlled climate scenarios
• Flood and drought forecasting systems
• National Water Resources Audit eg. Prototype web tool by IWMI
http://idistest.iwmi.org:8080/slwa/
• Comprehensive national study on vulnerability of water resources and
agriculture to climate change covering:
– Both surface and ground water
– Water quantity and quality
– Combined impact of enhanced CO2 + temperature +
increased/decreased rainfall on agriculture
• Central agency to cater to the need for corporation and data sharing
Water for a food-secure world

16. THANK YOU !
ACKNOWLEDGEMENTS:
• Mr. Lalith Chandrapala, National Disaster Mitigation Council (NDMC)
• Dr. B. V. R. Punyawardane, Department of Agriculture
• Ms. Dharshanie De Silva, World Bank
• Ms. Chandanie Panditharatne, Ministry of Environment and Natural Resources
• Mr. Sarath Premalal, Department of Meteorology
• Mr. Bandula Wickramarachchi, Coast Conservation Department (CCD)
• Mr. N. Wickramaratne, Mahaweli Authority
• Mr. H. M. Jayatillake, Irrigation Department
• Mr. K. A. U. S., Imbulana, Ministry of Irrigation
• Mr. L. Manawadu, University of Colombo
• Dr. W. M. W. Weerakoon, Rice Research and Development Institute (RRDI)
• Ms. Karin Fernando, Centre for Poverty Analysis (CEPA)
• Dr. G. G. A. Godaliyadda, Irrigation Department
• Dr. A. W. Jayawardena, Public Works Research Institute, Japan
• Mr. Gerard Fernando, National Water Supply and Drainage Board
• Mr. Harsha Sooriyarachchi, Water Resources Board
• Staff of Sri Lanka Association for the advancement of Science (SLASS)
• Dr. Herath Manthrithilake (IWMI)
Water for a food-secure world

17. Top ten Natural Disasters from 1901 to 2000Number Affected
Number Affected Damage (000 US$)
2500000 1000000
2000000 100000
10000
1500000
1000
1000000 100
500000 10
0 1
Tsunami 2004
Tsunami 2004
Flood 1983
Flood 1969
Flood 2003
Flood 1989
Flood 1992
Flood 1991
Flood 2003
Flood 1969
Flood 1966
Flood 1967
Storm 1978
Storm 1978
Storm 1964
Flood 1989
Drought 1982
Drought 1987
Drought 2001
Drought 1988
Source: "EM-DAT: The OFDA/CRED International Disaster Database
Water for a food-secure world