Tsunami preparedness and resilience: Evacuation logistics and time estimations

Abstract

Extensive research has studied the near-field tsunami threat in the Cascadia Subduction Zone (CSZ), but little research has examined the ability to evacuate the inundation zone before the first tsunami wave arrives. To address this gap, this study provides empirical evidence about people’s expectations about hazard onset and evacuation logistics when a tsunami threatens. We surveyed households in five CSZ communities to assess residents’ expected first wave arrival time, as well as their expectations about evacuation destinations, route choices, preparation times, travel times, and clearance times. Heatmaps are used to summarize residents’ evacuation destinations and route choices, and probabilistic functions are used to model evacuation distances and time estimates. The results suggest that respondents have similar patterns of time estimates, but a few plan to evacuate within the inundation zone, and some plan to evacuate on routes that were congested in a previous event and end their evacuations at destinations within the inundation zone.