IMPROVEMENT OF ASSESSMENT FOR DRIFTWOODS DISASTER RISK BY FLOOD SIMURATION AND IT’S DAMAGE EVALUATION

Abstract

 We attempted to improve the assessment of driftwoods disaster risk by Yano et al. (2018) by adapting flood simulation due to accumulation of driftwoods and including the damage evaluation. This improved method was applied to the Kagetsu River basin where three historical recorded floods attacked in 2012 and 2017. From the results, it is shown that this model can predict not only accumulation of driftwoods, but also inundation by the driftwoods due to location of the bridge, river discharge and geographical condition. Also, driftwoods disaster risks including the damage amount due to the inundation can be evaluated quantitatively by this new method.