ANALYSIS OF SPATIOTEMPORAL CHARACTERISTICS OF ANNUAL MAXIMUM RAINFALL USING A LARGE-ENSEMBLE DATASET(d4PDF) : APPLICATION TO TOKACHI RIVER BASIN

Abstract

 The advantages of using a large ensemble dataset is not only to evaluate occurrence probability of period and basin averaged rainfall but also to evaluate spatiotemporal characteristics of heavy rainfall from several thousands years rainfall data. In this study, we analyzed spatiotemporal distribution of annual maximum rainfall over Tokachi river basin in Hokkaido, Japan under historical and warmer climate condition from a large-ensemble dataset. The results showed that spatiotemporal distribution of annual maximum heavy rainfall under warmer climate condition is more concentrated. Because the concentration of rainfall causes increase of peak discharge and change of characteristics of flood damage, this change of rainfall characteristics included increase of rainfall amount must be considered for flood disaster prevention plan.