STUDY ON SPATIAL DISTRIBUTION OF WASHED AWAY HOUSES IN THE CHIKUMA RIVER FLOODING CAUSED BY TYPHOON HAGIBIS IN 2019 -APPLICATION OF A COUPLED METHOD FOR RIVER AND FLOODING FLOW ANALYSIS-

Abstract

 Huge floods due to heavy rain have occurred in the world and caused severe house damages. It is therefore necessary to evaluate the relation between flood flow and house damage. The purpose of this paper is to evaluate the relation between flood flow and house damage in the Chikuma River flood caused by the Typhoon Hagibis in 2019. For this, a combined analysis of river flow and inundation flow was conducted. The calculated results showed that the flood flow from the breach point was separated into three directions, and the flow direction of high fluid force was comparable to the band profile of the house loss. However, the fluid force and velocity on the houses away from the breach point was small, suggesting further improvement of the numerical accuracy using fine computational grid.