Abstract
The application of regional climate model simulations (RCMs) in climate change impact studies is challengeable due to the risk of possible biases. Some sort of correction needs to be done prior to the application of RCM simulations. This study attempts to assess the performance of a simple (linear scaling and Delta Change method) and complex correction technique (Local intensity scaling, Power transformation and Distribution mapping) on CORDEX(Coordinated Regional Climate Downscaling Experiment)simulated precipitation series for the Thanjavur district. The performance at annual resolution is evaluated using various statistical parameters such as Correlation, Root Mean Square Error and Bias against the observed precipitation data. The raw RCM estimates were improved significantly after the bias correction with all methods. However, Power transformation exhibits good agreement with the observed data at the district level than other methods because it corrects both the mean and variance. The future climate was projected from 2021 to 2100 for RCP 4.5 and RCP 8.5 scenarios. The temporal distribution of future precipitation clearly shows that most of the years will receive heavy precipitation; rather, some years will receive low and average precipitation. The spatial distribution pattern indicates that the northeast monsoon will dominate over all the ranges and places. This study has provided clear information on future precipitation to the environmentalist, urban planners, and policymakers to take appropriate mitigation measures towards agriculture and disaster management. Rainwater harvesting, recharging the aquifers, afforestation, and redirecting the excess amount of water to the river through proper channels is the plausible actions suggested overcoming excessive precipitation in the future.