Analysis of Flood Risk for Vulnerable People Using Assumed Flood Area Data Focused on Aged People and Infants

Abstract

During a large-scale disaster in Japan, vulnerable people, such as aged people, injured and sick people, infants, pregnant women, and foreign visitors to Japan, are most likely to be affected. This trend has not changed even in the case of floods where the process of disaster development is relatively moderate. However, in the case of flood disasters, the impact on vulnerable people can be minimized by evaluating the actual damage condition. The purpose of this study is to estimate the flood risk in the event of flooding for the elderly, the injured and sick, and infants, among those who need special care during disasters. The infant population was calculated using data from the national census maintained by Japan, and the aged and injured population was calculated using the National Health Insurance data, which are medical big data. Using these data, the regional distribution of the population was calculated, and then a spatial analysis was conducted with the data on the expected flood area in the event of flooding to estimate the exposed population. Through the analysis in this study, it was possible to estimate the flood risk per township by attribute, focusing on the aged, injured and sick, and infants. In Komatsu City, Ishikawa Prefecture, which was the subject of analysis in this study, the exposure of the elderly population in Mukaimotoori, Imae, Shirae, and Oki was high. In addition, the exposure of the infant population was high in Imae, Oki, Shirae, and Hitotsuhari. Town characteristics with a large exposed population were obtained, which is expected to be utilized for preliminary planning in the event of a flood.