Strategic flood evacuation planning facilitates effective transfer of vulnerable population in coastal megacities

Abstract

Abstract Emergency responders in coastal cities are always required to provide effective operations to evacuate at-risk populations during the preparedness and response phase of threatening storm floods. However, existing contingency plans primarily focused on the evacuation of general public rather than special arrangement for vulnerable populations who constituted a large proportion of flood fatalities. Here, we present a system-level methodology to elaborate citywide coastal flood evacuation plans for optimal deployment of shelters and effective transfer of groups with special needs. We conduct a comparative analysis between Shanghai and New York City (NYC) which are both among the most exposed coastal megacities to flooding, but represent two distinct institutional systems of emergency operation. The results show dramatic disparities in evacuation patterns for the elderly people of the two cities, and demonstrate the improved performance of risk-informed, strategic evacuation planning in advance of coastal flooding. Our work provides new insights into operational emergency evacuation decisions and informs flood management policy development for major coastal cities globally.