| The present study aims to reveal the characteristics of flood flow with a large amount of fine sedimentsupply in the Gofukuya river in the disaster caused by Typhoon No.19, 2019. Since numerous landslidesand debris flows occurred in the mountainous area of the Gofukuya river, a large amount of fine sedimentwas supplied and deposited at the plane area of the basin, that exacerbated the flood disaster. The presentstudy proposes a method to evaluate the fine sediment runoff from the basin by considering the sedimenterosion of the deposited sediment. The computed result of flood flow with fine sediment supply reproducesthe flood hazards in terms of the thickness of sediment deposition and the sediment size distributionincluding the obvious longitudinal sediment sorting. |
