Warning and evacuation: answering some basic questions

Abstract

Sorensen, J.H. and Mileti, D.S., 1988. Warning and evacuation: answering some basic questions. Industrial Crisis Quarterly, 2: 195-209. In this paper we address five questions that are frequently asked in the context of emergency planning for various accidents and disasters. These questions are commonly voiced by emergency managers or planners wanting a better basis for developing emergency response plans. The questions are frequently answered by people who have an image of how people behave in an emergency; often, however, their observations are inaccurate and misleading. The questions are as follows. First, how long does it take to warn a population about a crisis? Second, how many people evacuate in an emergency situation? Third, when do people evacuate? Fourth, do people evacuate unnecessarily? Fifth, where do people go when they evacuate?The major findings are as follows. First, most emergency response systems, which typically consist of law enforcement, firefighting and other civic employees, and sometimes volunteers, coupled with emergency use of available electronic media, can issue an effective warning given three or four hours of lead time. In some situations, when the threat is urgent, a warning can be disseminated in a much more rapid fashion. In situations with less than one hour of available warning time, some, and perhaps a substantial portion of the population will not receive a warning.Second, the speed of warning dissemination, particularly in urgent situations, is increased by informal warning processes. People seek information following the receipt of the warning and one common way to do so is to contact Downloaded from 196 friends, relatives or neighbors. In some of the situations studied, 50% of the initial warning was attributable to informal notification processes. Third, when advised or ordered to take a protective action such as evacuation, few people respond instantaneously except when there is a recognized and immediate threat. The length of time it takes for people to respond is variable among events, depending on the available time to impact and the severity of the threat. In any event, people are unlikely to take action simultaneously; rather it will be spread out over time.

The Impact of Information and Risk Perception on the Hurricane Evacuation Decision-Making of Greater New Orleans Residents

“…For example, Sorensen and Mileti (1988) suggested that the media plays a significant role in events that have long lead times; however, in rapid developing events, people tend to depend on a mix of sources when determining their actions. This mix, according to Sorensen and Mileti (1988), includes the mass media; emergency officials; and friends, neighbors, or relatives. Social networks, then, presumably play a large role in the evacuation behavior of people.…”

Regional Evacuation Modeling: A State of the Art Reviewing

“…However, until quite recently, as Sorensen and Mileti (1988) point out, relatively few of these studies have provided concrete evidence on just when, where, and in total how many people w i l l choose to evacuate during a particular type of crisis.…”

“…Although evidence from a number of chemical accident, flood and hurricane related evacuations have been published (see Baker, 1979;Sorensen and Mileti, 1988; Rogers and Sorensen, 1989;, such data was either not originally collected or reported with an eye to its subsequent use within detailed network routing and destination planning models: or the information was simply not available in any statistically reliable form at the level of spatial resolution required. Figure 1 shows a selection of traffic mobilization curves, based upon post evacuee survey data.…”

Development of an algorithm for automatic elaboration, representation and dissemination of landslide monitoring data

“…For example, the EWSs can be communication systems linking a variety of organizational actors to each other and then to the public (Sorensen and Mileti 1988;Mileti and Sorensen 1990;Sorensen 2000;Xu and Zlatanova 2007). Therefore, a properly designed EWS can link science, technology, levels of government and public.…”