Optimization of emergency shelter allocation and supply distribution route planning considering road reliability under flood scenarios

Flood disasters impair transportation networks, reducing accessibility of shelters and emergency supply routes. Existing emergency plannings assume road reliability and seldom account for flood-induced disruptions in shelter allocation and supply distribution. To address this gap, this study develops an integrated framework for emergency shelter allocation and supply distribution planning under flood scenarios. For road reliability assessment, betweenness centrality is incorporated as a key indicator to identify critical road segments and capture their topological importance within the road network. For shelter allocation, both surrounding flood inundation conditions and road reliability of candidate shelters are incorporated into the allocation process. For supply distribution, K-means clustering is employed to group shelters into distribution zones. A multi-objective routing optimization model is built with minimizing travel time and maximizing route reliability using NSGA-II algorithm. The framework is applied to Fengxian District, Shanghai, China. The results indicate the improved shelter allocation model enhances safety and accessibility of selected shelters. The Pareto-optimal solution set reveals trade-offs between travel time and route reliability, providing diversified decision support for route planning. The proposed framework provides scientific decision support for municipalities and emergency management agencies in flood preparedness and emergency logistics management, and is transferable to other flood-prone urban areas.