Climate Change Impacts and Adaptation Measures for Pahala Divul Wewa, Anuradhapura, Sri Lanka

Abstract

Present study was carried out to identify possible threats of various climate change scenario and suggest the possible adaptation measures for the food and water security corresponding to irrigation reservoir scale. Pahala Divul Wewa with a catchment area 5.12 km2, in Anuradhapura is located within DL1 agro-ecological zone was selected. The Irrigation Guide-line model was optimized for present situation of irrigable area. Five (5) scenarios of climate change were developed based on literature. Change in the precipitation due Climate change were used for a reservoir operation. The worst climate change scenario for Pahala Divul wewa was identified as the with 22% increase in SouthEast monsoon and 42% decrease in North East monsoon. The cropping intensity under this scenario was reduced from 0.678 to 0.55 a decrease of 13%. Since, Cropping Intensity of Pahala Divul Wewa was noted to reduce, several adaptation measures were identified to minimize the effects. Increasing Canal Efficiency was found to be most effective adaptation measure though it is less economical. It is recommended to incorporate climate change while designing the new schemes and Existing design rainfall, evaporation and other inputs shown in the guidelines need updating.