APPROACH TO CALCULATION OF MAXIMUM DISCHARGE DISTRIBUTION BY USING RANDOM CASCADE MODEL

Abstract

The objective of this study is to calculate the maximum discharge distribution corresponding to the distribution of annual maximum daily rainfall by using random cascade model.This model is used to probabilistically disaggregate daily rainfall generated according to its probabilistic distribution, then maximum discharge is calculated from disaggregated hyetographs by using a runoff model. This technique is applied to the Doki river basin, a small basin, where the influence of human activities is very limited. The observed discharge of annual maximum from 1976 to 1998 was used to verify the calculated distribution of maximum discharge. It is shown that calculated distribution of maximum discharge reproduced well. Furthermore, the cover ratio of the conventional method to compute design flood is evaluated.