Author(s): Yoko Taniguchi, Makoto Nakatsugawa, Keigo Otani
Linked Author(s): YOKO TANIGUCHI
Keywords: Water resources, statistical downscaling, MRI-NHRCM20.
Abstract: This study aims at obtaining basic information toward the development of countermeasures against water resource shortages in cold, snowy areas that may result from global warming. In this study, the influence of global warming is assessed at the local level by using climatic variation projection data that is based on the IPCC Fifth Assessment Report (hereinafter: IPCC AR5) and by using the Toyohira River basin in Hokkaido as the subject area. The Representative Concentration Pathways (RCP) Scenario of the IPCC AR5 consists of four scenarios: RCP 2. 6, RCP 4. 5, RCP 6. 0 and RCP 8. 5. The radiative forcing projected for the year 2100 under these scenarios is greater for each successive scenario listed above. In this study, a statistical downscaling method is used to convert 20 km-mesh climate projection data that has been created based on these four RCP scenarios to 1 km-mesh climate projection data. The changes in water resources in the Toyohira River basin in Hokkaido are quantitatively assessed by using the downscaled model. In the Toyohira River basin, the net annual precipitation projected by using the RCP8. 5 scenario is about 15% less than that of the projected present-day climate value. It is also projected that, in the year in which the decrease in the net annual precipitation is the greatest, the net annual precipitation is projected to be about half of that of the present climate. Under the RCP2. 6 and RCP4. 5 scenarios, in which the net annual precipitation is not much different from that of the projected present-day climate, changes are observed in hydrological variables, such as an increase in rainfall's share of total precipitation
Year: 2017