STUDY OF DISASTER OCCURRENCE SITUATION IN SANHASAMA RIVER BY THE SEPTEMBER 2015 KANTO AND TOHOKU HEAVY RAINFALL

Abstract

A large number of houses have been damaged and eight people have been affected by the September 2015 Kanto and Tohoku heavy rainfall disaster. Two of them were suffered in Sanhasama River. One has fallen into the river while driving through a collapsing bridge. The detail situation of the other has not been specified. Therefore, this study evaluated the disaster situation by three perspectives, the external factors (rainfall, water level), the terrain factors and the flood flow regime. In each perspective, some factors were identified that people had been believed them as secured in misunderstanding ways. It seems to have resulted in the lack of disaster awareness and a higher risk of severe disasters.