CHANGES IN FLOOD DAMAGE THROUGHOUT JAPAN DUE TO CLIMATE CHANGE AND LAND-USE CHANGE USING SHARED SOCIOECONOMIC PATHWAYS

Abstract

 This study evaluated the effect of climate change and land-use change on flood damage using climate scenario data by shared socioeconomic pathways (SSPs) throughout Japan. The inundation depth caused by flooding was calculated using a two-dimensional unsteady flow model. The flood damage cost was calculated by multiplying the asset value of the inundated land by the damage rate based on the inundation depth. Extreme rainfall in future climates was estimated from the output values of five general circulation models. The increase rate of the expected annual damage cost (EADC) in the near-future climate (2031–2050) was estimated to be 2% under the SSP1-2.6 and 7% under the SSP5-8.5 compared to the baseline climate (1981–2000). The EADC decrease rate in the late 21st-century climate (2081–2100) was estimated to be 33% under the SSP1-2.6 and 11% under the SSP5-8.5 compared to the baseline climate.