INFLUENCES OF SPATIAL RESOLUTION OF RAINFALL DISTRIBUTION ON RUNOFF ANALYSIS TOWARD CLIMATE CHANGE IMPACT ASSESSMENT

Abstract

 This study aims to reveal the optimal spatial resolution of rainfall that is necessary for flood analysis using General Circulation Models (GCMs) and Regional Climate Models (RCMs) in climate change impact assessment study in local scale.Therefore, we made an attempt to evaluate the impact of different spatial resolution of rainfall on runoff analysis by using a distributed hydrological model and dynamical downscaling (DDS) experiments on selected past flood events. As the result, it is found that rainfall distribution and runoff analysis are different between JRA-55 20km, 5km, 2km and 1km DDS experiments. Furthermore, it is confirmed that peak discharge in runoff analysis is not affected by aggregated rainfall distribution based on JRA-55 1km DDS experiments relative to runoff analysis with DDS experiments.