Allocation optimization of evacuation leaders in open public places: A case study of Binjiang Green Space in Xuhui District, Shanghai

Abstract

Emergency evacuation guidance is important in the safety planning of urban open public places. In order to solve the problem of spatial allocation of evacuation leaders at the early stage of emergency evacuation, a new allocation optimization method of evacuation leaders in open public places was built based on the particle swarm algorithm and gradual covering model. The method considers the influence of obstacles on the intervisibility, the spatial covering range, the distance decay effect of leaders' guidance, and the guided evacuee number threshold for each evacuation leader. Taking Binjiang Green Space in Xuhui District, Shanghai Municipality as an example, we conducted the allocation optimization of evacuation leaders. Using the agent-based evacuation model, emergency evacuation guidance simulations were conducted to verify the feasibility of the method by comparing the evacuation efficiency before and after the optimization. Meanwhile, considering the difference of crowd distributions in several time periods of a day, the dynamic planning of leaders' responsibility areas was conducted. The analysis results show that the demands for evacuation leaders varied at different moments and were proportional to the number of evacuees. The evacuation time cost of the optimized evacuation leader allocation scenario was much lower than that of the artificial allocation scenario. The division of the evacuation leaders' responsibility areas helped to clarify the area that each leader was responsible for and the daily safety precautions that should be taken under the limited leader number situation. This study can provide a decision basis for the spatial allocation of evacuation leaders in urban open public places, reduce the potential safety risks, and promote the construction of urban public safety.