A Multiobjective Approach to Locate Emergency Shelters and Identify Evacuation Routes in Urban Areas
Alcada-Almeida, Luis, Tralhao, Lino, Santos, Luis, Coutinho-Rodrigues, Joao, Geographical Analysis
Evacuation planning is an important component of emergency preparedness in urban areas. The number and location of rescue facilities is an important aspect of this planning, as is the identification of primary and secondary evacuation routes for residents to take. This article introduces a multiobjective approach to identify these aspects of evacuation planning. The approach incorporates a multiobjective model into a geographical information systems-based decision support system that planners can access via the Internet. The proposed approach is demonstrated with a case study for the City of Coimbra, Portugal, for evacuation during major fires. Although presented in this context, this approach is applicable to other emergency situations such as earth quakes, floods, and acts of terrorism.
Fires and other catastrophes are an important concern for fire departments and Emergency Medical Services (EMS) in urban areas. In this article, we present a Web-based decision support system to assist fire departments and EMS in the design of evacuation plans for an urban area. The plans include the determination of the number and location of rescue facilities (henceforth these will be referred to as "shelters") as well as the routes that individuals should take to reach their assigned shelter. The core component of the system is a multiobjective extension of the p-Median model (ReVelle, Marks, and Liebman 1970; ReVelle and Swain 1970; ReVelle et al. 1977; Rosing, ReVelle, and Rosing-Vogelaar 1979; ReVelle 1997). In addition, it includes various multicriteria tools to aid decision makers in the selection of their most preferred option. Although the system was designed specifically for emergencies related to fires in Coimbra, Portugal, the basic framework and model could be adapted to other evacuation situations (e.g., floods, acts of terrorism, etc.) in other cities.
The underlying problem is a multiobjective location/routing problem. There is a long tradition of multiobjective location problems (see, e.g., Current, Schilling, and Min 1990b; Daskin 1995; Current, Daskin, and Schilling 2001 for reviews) and multiobjective routing problems (see, e.g., Current and Min 1986; Current and Marsh 1993 for reviews). The mathematical model at the core of our approach also follows a long tradition of location models addressing emergency situations (e.g., Toregas et al. 1971; Schilling et al. 1979; Church and Weaver 1980; Schilling et al. 1980; Daskin and Stern 1981; Daskin 1982; ReVelle 1989; ReVelle and Snyder 1995).
There are numerous historic examples of catastrophic fires (e.g., Chicago, October 9, 1871; Boston, November 9, 1872; Baltimore, February 7, 1904; San Francisco earthquake and fire, April 18, 1906). Various European and Asian cities (e.g., Dresden, London, Tokyo) were ravished by fires during World War II. Recent events have made emergency service planners in Coimbra particularly conscious of the possibility of a catastrophic fire. According to Reuters News Service, 2003 and 2005 were the worst years on record for fires in Portugal (http://www.planetark.org/dailynewsstory.cfm/newsid/37062/newsDate/30-Jun2006/story.htm). On August 24, 2005, Coimbra was surrounded by forest fires with more than 300 firefighters working to contain flames on the edge of the city (e.g., BBC News: http://news.bbc.co.uk/1/hi/world/europe/4175922.stm).
According to the United States Fire Administration (USFA), approximately 4000 Americans die and 20,000 are injured each year in fires with 83% of the civilian deaths occurring in residences (http://www.usfa.dhs.gov/statistics/quickstats/). USFA studies indicate that "[a]dults age 65 and older are 2.5 times more likely to die in fires than the overall population" and "[s]moking continues to be the number one cause of residential fire deaths" (http://www.usfa.dhs.gov/safety/) in the United States. USFA states that" ... having a sound escape plan will greatly reduce fire deaths and protect you and your family's safety if a fire occurs" and that" . …