Abstract
　In this study author defined centrl concentration of hravy rainfall by utilizing the DA-curve formula which describes the characteristics of areal concentration of heavy rainfall and studied some charateristics of concentration of one-hour-rainfall of the Heavy Rainfall on July 1982. K, central concectration factor of areal distribution of the rainfall is given by K≒Iog(P0/Pm). Parameter n which represents concentration around the center of the rainfall is celculated by
　　n=(log[1-{log(P/Pm)}/K])/log(A/Am)
where, P, P0 and average rainfall amount on the area A and at the peak point and on the typical area Am respectively(0.1≦A/Am≦0.7).

【キーワード】：集中豪雨, 集中度, DA解析

*高知大学農学部
Faculty of Agriculture, Kochi Univ.