PROPOSAL OF FLOOD HAZARD INFORMATION BASED ON EROSION POTENTIAL OF LEVEES IN RIVERS OF TOYAMA PREFECTURE

Abstract

 The purpose of this study is to propose a flood inundation hazard map for each flood inundation site, taking into account the risk of levees erosion potential, in order to support local residents to recognize the risk of their own residential areas and to promote evacuations for the flood disaster mitigation. Therefore, in this study, flood inundation analysis was conducted for the Oyabe, Sho, Jinzu, Joganji, and Kurobe Rivers in Toyama Prefecture, and the flood inundation probability at each grid was calculated. The results of the analysis show that the probability of inundation in the inner area of the levee, the probability of inundation above floor level, and the probability that horizontal evacuation were affected by the erosion potential of the leeves. Also, it was found that the risk of inundation of the Jinzu River is particularly high and there is a high probability of flooding and the need for horizontal evacuation, especially in the lower reaches of the Jinzu River and low elevation areas. It should be emphasized that the right bank of the Jinzu River needs to be given higher priority than other rivers in terms of erosion countermeasures.