Optimization Model Based on Reachability Guarantee for Emergency Facility Location and Link Reinforcement

Wuyang Yu,Jijun Liu

doi:10.1155/2020/4648908

Abstract

The reasonable location of emergency facilities plays an important role in both predisaster service and postdisaster relief. Moreover, damage to the transportation network often affects the accessibility of demand points, which can seriously hamper timely rescue operations. Reasonable location of emergency facilities and reinforcement of fragile roads are two important strategies to improve the reachability of demand points. In this paper, we proposed a biobjective optimization model to determine locations of emergency facilities and links to be reinforced given a limited budget. Each demand point is allocated a primary facility and a backup facility, the former can provides normal service, and the latter is prepared for postdisaster relief. One goal of the model is to minimize the operating cost of normal services, and another goal is to maximize the reachability guarantee of demand points. The novelty and contribution of this paper are that we defined the reachability by introducing damage tolerance instead of link failure probability. Based on this, we defined the reachability guarantee to deal with the worst scenario of disasters. By embedding the max-flow problem of the reachability guarantee into the emergency facility location problem, the locations of emergency facilities and links to be reinforced can be determined simultaneously. The methodology is applied to a simplified Sioux Falls transportation network. Results such as the trade-off curve of two goals, budget efficiency, and the effect of reinforcement demonstrated the effectiveness of the model.

Highlights

According to the statistics of the International Disaster Database, the average number of recorded natural disasters event per annum of the nearly 10 years is about 333, almost twice as many as in the 1980s [1]. e sharp increase in natural disasters has highlighted the importance of disaster mitigation and preparedness [2], as the target of mitigation is to reduce the vulnerability of the affected regions, and the aim of preparedness is to facilitate emergency response and relief by using available resources
E reasonable location of emergency facilities plays an important role in both predisaster service and postdisaster response
Damage to the transportation network often affects the accessibility of demand points, which can seriously hamper timely rescue operations [4]

Summary

Introduction

According to the statistics of the International Disaster Database, the average number of recorded natural disasters event per annum of the nearly 10 years is about 333, almost twice as many as in the 1980s [1]. e sharp increase in natural disasters has highlighted the importance of disaster mitigation and preparedness [2], as the target of mitigation is to reduce the vulnerability of the affected regions, and the aim of preparedness is to facilitate emergency response and relief by using available resources. Damage to the transportation network often affects the accessibility of demand points, which can seriously hamper timely rescue operations [4]. Since the strategy to reinforce fragile roads is very useful to improve the accessibility of demand points after a disaster, an important problem in the preparation stage is how to determine the locations of emergency facilities and links to be reinforced given a limited budget?. Erefore, almost all current studies that related to the abovementioned problem involve randomness or uncertainty Most of these studies are based on similar assumptions that network links. We proposed a biobjective optimization model to determine locations of emergency facilities and links to be reinforced given a limited budget.

Literature Review

Figure 1

Findings

Model Formulation e main assumptions of the problem are summarized as follows: