EVALUATION OF COUNTER MEASURES OF FLOOD DAMAGE COST REDUCTION BASED ON FLOOD INUNDATION SIMULATION IN RIVERS OF TOYAMA PREFECTURE

Abstract

 Severe water-related disasters occur in Japan almost yearly due to typhoons and frontal rains. Particularly in recent years, the scale and frequency of torrential rains have been increasing due to global warming. The purpose of this study is to evaluate the damage cost reduction effects of several counter measures based on flood inundation simulations. The flood inundation simulations considering the climate change impacts were conducted at the Oyabe, Sho, Jinzu and Joganji Rivers in Toyama Prefecture. We then evaluated the effects of vegetation management in the river channel and rice paddy dams in the basins on the flood damage cost. From the results of analysis, it was found that the impact of vegetation management was a decrease in the flood damage cost throughout the rivers in Toyama Prefecture. The rice paddy dam was found to be effective in the Oyabe River, which has a large proportion of paddy fields in the basin.