ANALYSIS OF CAUSE OF HEAVY RAINFALL OVER TOKACHI RIVER BASIN UNDER HISTORICAL AND WARMER CLIMATE CONDITIONS USING A LARGE-ENSEMBLE DATASET(d4PDF)

Abstract

 In this study, we investigated weather patterns which caused heavy rainfall over Tokachi river basin in August and September under historical and future climate by using large ensemble dataset in order to clarify alarming weather patterns. Heavy rainfall events were classified into three weather patterns(near TC, far TC, no TC) by the Self-Organizing Maps and tropical cyclone tracking data. The occurrence ratio is slightly different between historical and warmer climate condition, but increase of rainfall amount in each weather patterns is dominant in increase of mean rainfall amount. Because the rainfall concentrate in spatio-temporal in all weather pattern, heavy rainfall events under future climate are alarming for making adaptation plan in terms of increase of rainfall amount and concentration.