歴史洪水資料を利用した計画降雨算定手法

Abstract

In this paper we propose the flood quantile estimators which can employ historical and paleoflood information in flood frequency analyses.In addition to systematic observed data, the historical information is categorized into three classes; "censored" data, where the magnitudes of historical flood peaks are known, "binomial" data, where only threshold exceedance information is available and "range" data, where the magnitudes of historical flood peaks have error within predetermined range.Gumbel distribution is used as probabilistic model and its parameters are identified by maximum likelihood estimators with those systematic and historical data.This approach is applied to the historical data of flood water level in Lake Biwa and the effect of adding historical information to systematic data on parameter estimators is shown.