INVESTIGATION OF TSUNAMI EVACUATION RISK AND RISK MITIGATION STRATEGY IN COASTAL URBAN CITY USING LARGE-SCALE EVACUATION SIMULATION

Abstract

 Approximately 340,000 people's evacuation behaviours were simulated with a supercomputer for investigations of tsunami evacuation risks in a coastal urban city. The large-scale simulation that models individual detail movements clarified potential risks such as delays of evacuation due to congestions in evacuation routes and overcrowded situations at evacuation sites. Additionally, the simulation demonstrated that those potential risks could be reduced by an evacuation control based on tsunami inundation forecasts. Simulated results with different departure scenarios indicated that approximately 40 minutes lead time is available for evacuations without casualties in the study area. These results suggest that tsunami forecast that can be completed within the lead time can contribute to smoother evacuation behaviours.