ANALYSIS OF SPATIOTEMPORAL CHARACTERISTICS OF HEAVY RAINFALL UNDER HISTORICAL AND WARMER CLIMATE CONDITIONS USING A LARGE-ENSEMBLE DATASET(d4PDF)

Abstract

 Climate change may causes not only increase of plan period- and basin-averaged rainfall but also change of spatiotemporal characteristics of heavy rainfall. Because the change of spatiotemporal characteristics of heavy rainfall may increase flood discharge and change flood damage pattern, we need to predict its characteristics in order to make efficient flood damage mitigation plan. In this study, we analyzed spatiotemporal characteristics of heavy rainfall over Tokachi river basin and Tokoro river basin in Hokkaido, Japan under historical and warmer climate from a large-ensemble dataset. We also evaluated influence of tropical cyclone which is difficult to analyze because of shortage of observation record. The results showed that spatiotemporal characteristics of annual maximum heavy rainfall under warmer climate is more concentrated and influence of tropical cyclone on two river basins has different tendency in terms of spatiotemporal concentration.