Analysis of the Impact of Flood Risk Perception Time and Shelter Locations on Life Loss

In the Republic of Korea, annual flooding caused by typhoons and monsoon seasons results in significant human and economic losses, driving extensive research into disaster prevention and policy development. Traditionally, flood-related fatalities have been estimated using probability analyses based on historical data, focusing on factors such as inundation extents and at-risk populations. However, accurate casualty predictions require advanced approaches that integrate topographical details and dynamic unsteady flood simulations. Moreover, the effectiveness of flood warnings, public risk perception, and evacuation dynamics—considering shelter proximity and capacity—are critical to reducing casualties. This study focuses on the Dorimcheon River area in Seoul, South Korea, where extreme rainfall in August 2022 caused multiple fatalities. Using observed rainfall data, we conducted a two-dimensional unsteady hydrodynamic simulation of flood flows and integrated the results into a dynamic life-loss model. Time-varying flood extents, water depths, and flow velocities from the hydrodynamic model were combined with data on building and population distribution in inundation zones. The loss of life was quantified based on pre-determined flood warning timing, road networks, and shelter locations. This comprehensive framework allowed for more reliable estimates of the exposed population and potential fatalities. We analyzed how variations in flood risk perception timing, warning dissemination speed, and shelter locations influence casualty outcomes. Our findings identify critical factors that should be prioritized to minimize fatalities during extreme rainfall-induced flooding. These results provide valuable insights for disaster management policies, highlighting the importance of integrated strategies that combine hydrodynamic modeling, rapid warning systems, and optimized evacuation planning. By addressing these elements, this study offers actionable recommendations to enhance flood risk reduction efforts and mitigate life loss during future flooding events.