Reachability guarantee based model for pre-positioning of emergency facilities under uncertain disaster damages

Abstract

Many practices shown that appropriate locations of emergency facilities play important roles both in pre-disaster service and in post-disaster relief. However, damage to the transport network can adversely affect accessibility between emergency facilities and rescue points, thereby hampering timely rescue operations. To lighten this adversely affection, we proposed a multi-objective optimization model for pre-positioning of emergency facilities based on the concept of the minimum reachability guarantee. This concept was defined as the maximum damage that the road network can withstanding. One goal of the model is to maximize the minimum reachability guarantee for post-disaster relief and another goal is to minimize the operating cost for normal service. These two goals are modeled as the max-flow problem and the shortest path problem, respectively. We embedded these two problems into the p-center facility location problem to avoid the bi-level structure of the model. The methodology is applied to the Sioux Falls transportation network to illustrate the trade-off between the minimum reachability guarantee and the operating cost. In addition, by comparing the number of unreachable rescue points in the random disaster scenarios, the effect of the minimum reachability guarantee in the optimization model is proved.