2025 Volume 81 Issue 16 Article ID: 24-16011
Frequency and magnitude of the flood inundation disasters are increasing due to climate change in Toyama Precture, and adaptation measures should be implemented in the river basins. This study presents a cost-benefit analysis of flood damage and various adaptation measures for the Oyabe, Jinzu, and Joganji Rivers in Toyama Prefecture, using detailed 5 km mesh future climate data. Paddy field dams and vegetation management in the rivers are focused on this study because of the green infrastructure aspects and mitigation effects of the climate change. The evaluation results showed that paddy field dams were effective in the target rivers, especially in the Oyabe River, where the cost-benefit was 12.6 at 50% implementation rate and 14.9 at 100% implementation rate. Also, it was confirmed that the vegetation management in the rivers are useful as the counter measures from cost-benefit analysis. However, the general cost of the vegetation cutting should be reduced by selecting the target areas in the rivers and reducing the other related costs of the vegetation management.
