Integrated Modeling of Climate change impacts in the Yoshino River Basin, Japan for Basin Management Planning

Abstract

The Yoshino River provides the main water source for agricultural, industrial and domestic activities in Shikoku Island. This study aims to identify the impacts of climate change in the basin by identifying its temporal effects in the future using climate scenarios and the Water and Energy Budget-based Distributed Hydrological Model (WEB-DHM). Using spatially distributed gauge rainfall, the model was calibrated at Sameura dam for 1984. Bias correction was done for precipitation using GCM climate scenarios (from SRESA1b for the years 1982-2000 and 2046-2064). Focusing on possible water deficits, the standard anomaly index (SA) identified possible droughts in the observed (1982-2000), past and future GCM ensemble outputs. Results show that historical moisture deficits can be simulated. Past and future simulations on basin average rainfall and discharge show future maximum values to be much higher than past indicating increases in wet conditions that may have possible effects on water availability in the future.