Novel framework for assessing long‐term flood risk management pathways focusing on river channel improvement and amenity policies

Abstract

Many urban areas at higher flood risk owing to climate change, and mitigating these risks requires a combination of structural and nonstructural adaptation measures. Previous studies assessing adaptation measures are limited in quantifying the effects of climatic and social changes. As an interdisciplinary approach, this study developed an agent-based model of household locational choices and combined an advanced method for deriving on-site analytical flood risk curves (90 m resolution) to explicitly reflect the present/future flood risk on the flood insurance rate. To evaluate river channel improvements and amenity policies, the proposed framework was applied to a middle stream area of the Yodo River basin, Japan. The simulation results indicated that (1) both the design level and river pathway improvements influence the flood risk (2) developing wider areas over low-and no-risk areas rather than the intensive induction to limited no-risk areas lead to a more effective reduction in flood risk. In addition, (3) an appropriate amenity policy may contribute to the attenuation of the inequality of flood risk among regions owing to the pathway of improvement. The proposed interdisciplinary approach will help decision makers in long-term flood risk management.