FTAによる渇水の構造特性

Abstract

Recent years mainly in metropolitan areas drought problem happens frequently, so it constitutes a social problem. But a clear difinition of drought has not yet beformed, and various factors which cause drought are liable to be argued sensuouslyand empirically.Then in this paper we apply Fault Tree Analysis which is one of safety analy-sis, to drought event. And according to the causality between drought event andits factors laying stress on the water quantity, we clarify the structural characteris-tics of drought event.Concretely, taking Yodo River basin as an example we consider intake cut atHirakata as a specific defect event (Top event) of the whole system. Firstly FT di-agram is drawn according to the retroactivity process of its basic factors (Basicevents).Then with this FT diagram we study quantatively the causality between eventsby such indices as structural, probabilistic and critical importances.