FLOOD DISASTER CHARACTERISTICS IN MABI DISTRICT OF KURASHIKI CITY DUE TO HEAVY RAIN IN 2018 AND INVESTIGATION OF FLOODING SCENARIO USING RIVER FLOOD FLOW COMBINED INUNDATION FLOW MODEL

Abstract

 Due to the heavy rain of July in 2018, several levees of the Oda River flowing through the Mabi district of Kurashiki City and its tributaries, the Suemasa River, the Takama River, and the Madani River, were breached. Inundation area reached 1,200 ha in Mabi district and maximum inundation depth was more than 5 m, and eventually 51 people died there. First, in this study, the inundation state was clarified by the field survey. And flooding scenario was examined using an integrated flooding simulation model that analyzes the flood flow of rivers and the inundation flow from the breaching points. At first, the analysis was performed without breaching condition of levee to estimate the time to start overflowing the levee. Then simulations under breaching condition was carried out to clarify the inundation process. Numerical results of inundation depth show in good agreement with the field surveyed results.