CLIMATE CHANGE IMPACTS ON THE FLOOD HAZARD AND ECONOMIC RISK IN A JAPANESE CATCHMENT USING GCM PRECIPITATIONS UNDER THE A1B SCENARIO

Abstract

First this paper introduces an integrated flood risk assessment framework especially focusing on the economic damage estimation in a flood prone region using a very detailed vector-type GIS map which delineates precisely the shapes of the houses and crop fields. Then the paper tries to estimate a climate change impact on flooding in a river catchment using the precipitation outputs of a super high-resolution global climate model (GCM) with 20-km spatial resolution developed by the Japan Meteorological Research Institute (MRI). The MRI has carried out a numerical experiment of climate variation from the present (1979-2003) toward near future (2015-2039) periods under the climate change A1B scenario. Using the GCM precipitation data, the 100-year rainfalls of a catchment for the present and near-future periods are roughly estimated. Based on the 100-year rainfall change, the future change of the flood hazard and economic risk of the catchment are analyzed. The Hinogawa river catchment, Shiga, Japan and the Ryuou Town in the catchment are selected as the test sites.