A Study on calculation of Probable Maximum Precipitation (PMP) by taking into account of Depth-Area-Duration (DAD) characteristics of rainfalls

Abstract

In this study based on the scientific knowledge of today and observation data, Probable Maximum Precipitation (PMP) was investigated by taking into account of Depth-Area-Duration (i.e., the amount of rainfall – area – rainfall duration ) characteristics of rainfall eventually flown into rivers. The Japanese Islands were divided into 15 regions on the basis of similarity of rainfall characteristics with reference to existing division of region and by implementing cluster analyses after the indexes showing characteristics of intensive rainfalls were reorganized and coordinated. Subsequently, trial calculations to obtain the maximum possible level of rainfall by region, by fixed area and by rainfall duration were made.