LAUSR

Abstract Unpredictable and no-notice disasters such as flash floods and wildfires, have been increasing. Under such circumstances, large-scale evacuation is required and the population may not be able to be effectively relocated in time from the disaster-threatened zone. The evacuees may be risking their lives during evacuation traveling toward the designated shelters/safety zones. A Shelter-In-Place (SIP) strategy is proposed to provide immediate avoidance of hazards for communities. This study develops the optimization models to determine SIP deployment and evacuee assignment for the case of vertical evacuation (VE) in response to dam-break floods. Compared with general shelters located outside evacuation areas, SIPs are designed to be reachable on foot upon the occurrence of sudden disasters. Accessibility of SIPs is one of the primary concerns in the problem context of determining their locations. Multi-class evacuees are addressed in the SIP strategy, particularly for the elderly in consideration of their vulnerability in disasters and heterogeneous walking speed across different classes. Additionally, the spatially-varying risk over the disaster-threatened areas is also considered in the model. A dam failure scenario causing flooding is studied for Tucheng District, New Taipei City, Taiwan. The case study illustrates the effects of spatial risk consideration, elderly priority, and coverage distance on the optimal solution of shelter locations. The extent of improvement in emergency planning is also fundamentally related to the population distribution in the study area.