RCM5を用いたゲリラ豪雨をもたらす大気場の出現頻度の将来変化の推定

Abstract

In recent years, there have been flush flood damages caused by localized heavy rainfall, called ‘Guerrilla-heavy rainfall’ in urban areas in Japan. It has been pointed out that increasing rainfall events today can be due to global warming. Therefore, it is necessary to project the future changes of the frequency of such kind of rainfall events. In this study, we implemented some fundamental analysis in August in the Kinki Region, from the view point of both the rainfall distribution and the unstable atmospheric condition. First, we picked up guerrilla heavy rainfall events with visual judgement of rainfall distribution. Then, we analyzed the atmospheric stability of the events that was picked up, using a parameter SSI (Showalter Stability Index). As a result of T-test on the future changes, the trend of future change in the number of guerrilla-heavy rainfall events is similar to that of the number of unstable events.