Disaster prevention and evacuation system

Background and Purpose In municipalities designated as Special Tsunami Evacuation Measures Reinforcement Areas, disaster prevention policies have been strengthened to reduce human casualties from anticipated large earthquakes and tsunamis. This study focuses on Noboribetsu City, a coastal municipality in Hokkaidō, Japan, and aims to describe the development process of its Disaster Prevention and Evacuation System (DPES 3.1). The purpose is to clarify how disaster prevention policies have evolved and to assess their adequacy based on empirical evacuation behavior data. Research Approach The study integrates Geographic Information Systems (GIS), open data, tsunami hazard projections, and evacuation behavior data collected from residents during disaster drills. Winter evacuation data (evacuation speed, distance, and time) obtained from the 2025 comprehensive disaster drill were analyzed and compared with previously collected summer data. The comparative analysis identifies seasonal differences in evacuation behavior and derives measures necessary to reinforce tsunami evacuation planning in Noboribetsu City. Analysis Results Winter evacuation data included low-speed cases below 1 km/h due to snow and frozen road surfaces, with a speed distribution between 2 and 5 km/h and an average speed of 3.7 km/h. Summer data were more concentrated between 3.5 and 4.7 km/h, with an average speed of 3.9 km/h. These findings indicate that practical evacuation planning should incorporate measured evacuation speeds in addition to the national standard of 2.24 km/h to more accurately estimate evacuation feasibility and reduce human casualties. Conclusion Three policy implications emerge from the institutionalization phase of DPES (DPES 3.1). (1) Noboribetsu City’s assumed evacuation speed of 48 m/min (2.88 km/h) is realistic and appropriate. (2) Owing to the city’s topography, residents may face isolation at primary evacuation sites, necessitating implementation of secondary evacuation operation scenarios. (3) Evacuation distances should ideally be less than 1 km, with shelters located within a 500 m radius of households; therefore, installation of tsunami evacuation towers is recommended to strengthen evacuation capacity.