Regional evacuation modeling for toxic-cloud releases and its application in strategy assessment of evacuation warning

An assessment framework for an evacuation warning based on regional evacuation modeling for toxic-cloud releases is provided in this paper, which considers the impact of evacuation-warning dissemination and the calculation of health consequences. The modeling of regional evacuation accounts for several actual phases of the evacuation process. A division called an evacuation unit is proposed in the building process of a regional evacuation network, and a method to quickly calculate the movement time through the evacuation unit is presented. The loading process of evacuation flow is proposed, making it possible to change pre-movement efficiency by adjusting the overall pre-movement time in evacuation analysis. Apart from the movement of individuals through the regional evacuation network, the processes of warning diffusion and evacuation preparation are considered based on the analysis of the required egress time. The proposed regional evacuation model is applied in the analysis and comparison of evacuation warning strategies in the case study. The simulation results show the correctness and effectiveness of the strategy-assessment framework for evacuation warning, and the method proposed in this paper can be used as a tool to assist in emergency early-warning decisions.