The document summarizes climate change research related to Sri Lanka's water future. It reviews observed climatic changes showing warming trends and variable rainfall patterns. Climate projections suggest increasing temperatures and rainfall variability with higher floods and droughts risk. Impacts on water resources and agriculture are expected, including increased irrigation needs. Vulnerability mapping shows farming areas with low adaptive capacity are most at risk. Adaptation options and further research priorities are discussed.

1. CLIMATE CHANGE AND SRI LANKA’S WATER FUTURE Nishadi Eriyagama (IWMI)¹ Workshop on Vulnerability and Adaptation to Climate Change in the Water Resources Sector, Colombo, Sri Lanka, September 2009 1=International Water Management Institute, 2=National Disaster Mitigation Council,3=Center for Poverty Analysis Vladimir Smakhtin (IWMI)¹, Mir Matin (IWMI)¹, Lalith Chandrapala (NDMC)² & Karin Fernando (CEPA)³ With contributions from

6. CLIMATE PROJECTIONS - 2 Rainfall Increased Variability - Projections for this century confusing and contradictory! Source: Flowchart created by N.Eriyagama, 2009 Lower Mean Annual Rainfall Mean Annual Rainfall Higher Mean Annual Rainfall Increased Floods & Droughts Higher South-West Monsoon R/F Higher North-East Monsoon R/F Higher South-West Monson R/F Lower North-East Monson R/F Kumar et. al. 2006; Islam and Rehman undated; Basnayake et. al. 2004; Basnayake and Withanage 2004a Cruz et. al. 2007; De Silva 2006; Basnayake and Withanage 2004b Lower South-West Monsoon R/F Lower North-East Monsoon R/F Ashfaq et. al. 2009; Basnayake et. al. 2004

10. IMPACTS ON AGRICULTURE Impacts on Agriculture due to Altered Water Resources Source: Table compiled by N.Eriyagama, 2009 using data from Fernando et.al 2007, Wijeratne et.al 2007, De Silva 2006 & Wijeratne, 1992 Sea Level Rise: Inundation + Salt intrusion Paddy Tea Coconut Irrigation Requirement: 13-23% increase in Maha by 2050 (De Silva 2006) Yield: 100 mm monthly R/F reduction: 30-80 kg reduction in ‘made’ tea/ha (Wijeratne et. al., 2007) Heavy rains: erode top soil and wash away fertilizers, reduce yield (Wijeratne, 1992) Economy: Low rainfall: Losses in the range $32 - $73 million a year (lower yield) High rainfall: Gains in the range $42 - $87 million a year (higher yield) (Fernando et. al 2007)

11. CLIMATE CHANGE VULNERABILITY MAPPING -1 Source: Figures created by N. Eriyagama, 2009 using data mainly from the Department of Census and Statistics-Sri Lanka Climate Change Vulnerability Index Anuradhapura Nuwara-Eliya Ratnapura Sensitivity Index Exposure Index Adaptive Capacity Index

12. CLIMATE CHANGE VULNERABILITY MAPPING -2 0 – lowest vulnerability 100 – highest vulnerability Source: Figures created by N. Eriyagama, 2009 using data mainly from the Department of Census and Statistics-Sri Lanka Exposure Index based on: Frequency of exposure to historical droughts, floods, cyclones Sensitivity Index based on: Population density, % employed in agriculture, irrigation water availability, agricultural diversity (crops diversity, livestock farming, fishing) Adaptive Capacity Index based on: education level, poverty incidence, level of infrastructure development

15. SRI LANKA WATER RESOURCES AUDIT - 2 Source: http://idistest.iwmi.org:8080/slwa / Physical and Admin Settings Hydro/meteo Data Water Demand Water Infrastructure Natural Disasters