Estimation of regional maximum rainfalls based on Radar-AMeDAS precipitation

Abstract

This paper estimates regional maximum rainfalls, using the depth-area (DA) relationships based on the Radar-AMeDAS precipitation provided by the Japan Meteorological Agency. The DA relationships are derived for each of the twenty-seven climatic regions, which are defined in this paper for districts from Tohoku to Kyushu by statistical analysis of hourly and daily maximum rainfalls by the AMeDAS (1976-2004) etc.; the meteorological characteristics is regarded as the same within each climatic region. The rainfall durations considered are 1, 3, 24 and 48 hours, while the rainfall area ranges up to 28621km² or less. This paper proposes a new DA equation and compared it with the Hortonʼs DA equation conventionally used.