Climate Change Impact Assessment on Rice Yield Using Dssat and Geospatial Methods

Rice, a staple cereal crop feeding over half of the world's population. It grows in a variety of agro-climatic conditions and is mostly cultivated in Asia. Sudden increase in rainfall and temperature adversely impact on crop yield which leads to economical loss to farmers. The current research aims to assess climate change impact on rice yield produced in Hanumakonda district, Telangana, India where agriculture area is predominant. To achieve this, the yield was simulated over a 17-year (2007–2023) period for five different agricultural fields of Hanumakonda which has crop management information used by farmers in both Kharif and Rabi seasons using DSSAT (Decision Support System for Agrotechnology Transfer) CERES (Crop Environment Resource Synthesis)-Rice model. RMSE (Root Mean Square Error) and NRMSE (Normalized Root Mean Square Error) are the metrics used to verify the accuracy of simulated yield. The simulated yield is compared with observed data which was collected from Directorate of Economics and Statistics, Telangana. It is observed that the pattern of temporal variation of simulated yield over the years 2007-23 is aligning with the trend of observed yield variation for the same time period. Average NRMSE of all the sites is 13.02% for Kharif and 17.12% for Rabi. The average RMSE of all the sites is 408.07 Kg/ha for Kharif and 584.398 Kg/ha for Rabi. For impact assessment a second-degree polynomial regression model is fitted between climate variables and rice yield. The convincing coefficient of determination values of present fitted model confirms the predicting future rice yield for future climatic conditions.