Author(s): Yoshinobu Sato
Linked Author(s): Yoshinobu Sato
Keywords: Climate change; MRI-AGCM3.2s; River discharge
Abstract: To clarify the impact of climate change on river discharge, a hydrological simulation for all (109) class-A river systems in Japan was conducted. A super-high-resolution atmospheric general circulation model with a horizontal resolution of about 20km developed by Meteorological Research Institute of Japan Meteorological Agency (MRI-AGCM3.2S) was used for future projection. It has two different datasets, one representing the present climate (1979–2003) and the other representing the end of the21st century (2075–2099) assuming the spatial patterns in sea surface temperature (SST) changes obtained by the Coupled Model Intercomparison Project Phase 5 (CMIP5) under the Representative Concentration Pathways (RCP) 8.5 scenario. Then, future change ratio of river discharge was estimated using a distributed hydrological model. The results obtained in this study showed that river discharge in the spring season will decrease especially in the northern part of Japan (especially in the Tohoku and Hokuriku region, except of Hokkaido region). It will be mainly due to the increase in rainfall and decrease in snowfall in the winter season. Furthermore, in the case of central and western part of Japan (e.g. Tokai, Kansai and Shikoku Region), the water shortage will become more serious, mainly due to the lack of rainfall in June and August, and also due to the increase of evapotranspiration losses.
Year: 2016