DESIGN FOR FLOOD DISASTER-REDUCTION SYSTEM IN A FLOODPLAIN OF SMALL-MEDIUM SIZED RIVERS

Abstract

Present paper describes how to design a flood disaster-reduction system in a floodplain of small-medium river. It is intended to minimize damages such as human casualties resulting from a flood hazard, supposing an abnormal, excessive flood takes place. The system is composed of two methods; a mathematical simulation model for evaluating risk rank of local site in the flood plain and a kind of flood plain management such as a legal guidance of suitable land uses for reducing flood disasters. In practice, the authors illustrated the damage potential over the most of flood plains in Shiga prefecture using the simulated results on each risks rank and the corresponding occurrence probability and proposed a method to design the flood disaster-reduction system under the present legal and constitutional structure.