2018年7月豪雨の異常さと地球温暖化による影響評価

Abstract

The heavy rainfall event in 2018 was an extraordinary widespread and long-lasting heavy rainfall and caused a big damage. In this paper, we analyzed the abnormality of the heavy rainfall event in July 2018 in terms of some spacio-temporal scale indices, "atmospheric pattern", "the amount of water vapor inflow", and "the accumulated precipitation amount", by comparing with the ensemble output of present and future climate experiments of climate model. As a result, the frequency of similar atmospheric pattern to that of the event in 2018 will not increase in the future climate. However , the amount of water vapor inflow will remarkably increase, moreover the accumulated precipitation of meso-β localized heavy rainfall, that could be a trigger of disaster like landslide or flooding, will also become more intense in the future climate. It is indicated that the frequency of similar widespread and long-lasting heavy rainfall may not increase but if the similar one occurs, the total rainfall amount is possibly increase and the disasters will also become more severe.