Comparative analysis of tsunami casualty estimation approaches: Agent-based modeling versus simplified approach in Japanese coastal cities

This study aims to clarify the differences in the estimation of casualties from a significant earthquake and tsunami event between an agent-based model (ABM), which can capture detailed evacuation behavior but demands significant computational resources, and a simplified approach at less computational cost by assuming that evacuees would move along a straight line from their initial location to the closest evacuation destination.

Significant differences in the estimated results between the ABM and the simplified approach were found. Notably, when the effects of building collapse due to an earthquake were considered, the mortality rates estimated by the ABM were higher than those estimated by the simplified approach in the three cities. There were also significant differences in the spatial distribution of the estimated mortality rates between the ABM and the simplified approach. The findings suggest that while the simplified approach can yield results more quickly, casualty estimates derived from such models should be interpreted with caution.