FLOW CHARACTERISTICS OF DEBRIS FLOW WHICH WAS HAPPENED IN YANOHIGASHI, HIROSHIMA IN JULY, 2018

Abstract

 Field observation and numerical analysis were performed for the debris flow which was happened in Yanohigashi, Hiroshima in July, 2018. Three debris flows were happened and the soil saving dam was filled with the sediment of the debris flow from the south valley. The second debris flow from the north valley attacked the residential area and damaged many houses. The results of the numerical analysis show that the multiple valleys must be considered to estimate sediment transport rate to residensial area. In case of Yanohigashi, the soil saving dam didn’t work to suppres the inundation area of the debris flow in residential area.