面積平均的降雨の時間分布の統計的特性に関する研究 -連続最大配分率について-

Abstract

Because of application purpose such as more effective use of forecasted rainfall depth in floodcontrol by reservoir or examination of safety of design rainfall depth in water planning againstfloods, the author has studied probability distributions of the maximum distribution rate of rainfallto any sub-period in a fixed period by analysis of point rainfall data and simple mathematical model(random distribution model). But, it is better for such application purpose as above mentionedto know those of areal average rainfall.In this paper, under the asumption that areal average rainfall is given by simple mean of pointrainfalls, degrees of effect upon statistical characteristics of the maximum distribution rates toany sub-period by areal average are mathematically and semi-empirically examined in relationwith number of points and cross-correlation coefficient of hourly rainfalls.The most interesting and important result is that if cross-correlation coefficient is larger thanabout 0.8, the effects by areal average are almost negligible.