CLIMATE CHANGE ADAPTATION STRATEGIES IN THE BHAVANI BASIN USING THE SWAT MODEL

The present study aims to assess the impacts of climate change on hydrology and rice yield in the Bhavani Basin of India using the SWAT model. The investigation indicates that SWAT can be applied under a changing climate as a decision support tool for framing adaptation strategies such as altering the method of cultivation by changing water and fertilizer management. Climate change scenarios were developed using the RegCM3 model with EH5OM GCM output for an A1B scenario. The RegCM3 model tended to slightly underestimate the maximum and minimum temperatures. The generated daily climate data were used in the SWAT model for assessing the impact on hydrology and rice productivity of the river basin for a continuous time period of 130 years (1971-2100). To validate the SWAT model, predicted rice yields for the Bhavani Basin over a period of 11 years (1999-2009) were compared with the observed rice yields of Erode district in which the Bhavani Basin is located and the results indicated the satisfactory performance of the model. It is shown that the SWAT model can be employed under different climate change and management scenarios for developing adaptation strategies to sustain rice production. The SRI system of rice cultivation is found to be a better adaptive technology for changing climatic conditions than the conventional flooding system of cultivation in regards to water conservation (300 mm) and increasing yield (26%).