2025 Volume 81 Issue 16 Article ID: 24-16071
This study assessed the impact of inundation damage on the total population of a 500 m mesh in areas inundated by Typhoon Hagibis and the July 2020 heavy rains employing the difference-in-differences method. We also evaluated the influence of regional characteristics on population changes due to inundation damage. The results showed that the total population decreased with increasing inundation depth. The average rate of change in the total population per 500 m mesh cell due to inundation damage was estimated to be -2.9% in areas inundated by Typhoon Hagibis and -10.4% in areas inundated by the July 2020 heavy rains, compared to the case where no inundation damage had occurred. Furthermore, the impact of inundation damage on the total population varied with regional characteristics; for instance, the longer the distance to medical institutions, the greater the decrease in the total population due to inundation damage.
