2025 Volume 81 Issue 16 Article ID: 24-16009
We assessed the changes in exposed population due to fluvial flood, pluvial flood, and slope failure across Japan from 2015 to 2100, considering climate and population changes under Shared Socioeconomic Pathways. Exposed population due to flood inundation and inland water inundation was defined as the population living in the area where more than 45 cm of inundation occurred. Exposed population to slope failure was defined as the population living in the area where the probability of slope failure exceeded 80%. In all SSPs, the rates of change in the exposed population, including positive and negative rates, were higher for inland flooding, flood inundation, and slope failure, in that order. Especially in SSPs 5-8.5, the exposed population to internal flooding increased significantly. The results of the evaluation of the rate of change in the exposed population due to climate change and population change alone, respectively, indicated that the effect of population change was more dominant than that of climate change on the exposed population.
