Impact of El-Nino and La-Nina on Hydrology and Rice Crop Yield of Kharun Watershed, India : Application of Soil and Water Assessment Tool

In this paper, a study has been performed to understand the variations of hydrology and rice crop productivity during different El-Nino and La-Nina events in Kharun river watershed of Chhattisgarh, in India, using Soil and Water Assessment Tool (SWAT). Based on the National Oceanic and Atmospheric Administration (NOAA), affected years by El-Nino and La-Nina events are obtained between the duration of 35 years of analysis i.e. from 1981 to 2015. Result shows less rainfall and crop yield during El-Nino and normal rainfall and increased crop yield during La-Nina years. The validation results using SWAT shows good statistical results i.e. R² and NSE > 0.6, RSR < 0.6 and PBIAS under ±15 for stream flow and R² > 0.7 and PBIAS under ±10 for rice crop productivity; hence these studies are vital tool for policy makers for decision making of planning in the disaster management schemes.