ANALYSIS OF ANNUAL MAXIMUM PRECIPITATION OVER FIRST-CLASS RIVER DOMAINS IN JAPAN USING A LARGE-ENSEMBLE DATASET(d4PDF)

Abstract

 In this study, we analyzed annual maximum area averaged precipitation over first-class river domains in Japan (109 domains) from a large-ensemble dataset (d4PDF), which enable us to have better estimation of return period of heavy precipitation, in order to reveal the statistical dispersion of annual maximum precipitation and changing rate of heavy precipitation amount associated with climate change. The results showed that the statistical dispersion among 50 ensemble members of annual maximum precipitation during 60 years was different in region and the heavy precipitation amount in future climate simulation is higher in all first-class river domains. This result suggested that the countermeasures against floods will become even more important in the future associated with climate change.