FLOOD RISK REDUCTION EFFECTS OF URBAN STRUCTURAL CHANGES DUE TO REARRANGEMENT OF PUBLIC FACILITIES

Abstract

 In response to flood disasters, which are expected to become more severe due to climate change, it is becoming increasingly important to develop flood-resilient communities using urban planning methods. In this study, we estimated future changes of urban structure in the area around the Kakehashi River basin in Komatsu City, Ishikawa Prefecture, Japan by using a computable urban economic (CUE) model. The scenario assumed is the relocation and consolidation of elementary schools and the adjustment of the urbanization promotion area under the population decrease in 2045. Based on the results of inundation analysis using future rainfall based on a pseudo-global warming simulation as input, the flood economic losses before and after the urban structural change was calculated, and the flood risk mitigation effect of the assumed scenarios was evaluated. Relocation and consolidation of elementary schools had the largest decrease of 15.1% in the amount of flood economic loss. The combination of the relocation and consolidation of elementary schools and the change in the urbanization promotion area resulted in a 19.9% reduction in the flood economic loss, indicating a synergistic effect of the combination of measures.