Household evacuation behavior during a Natech accident

Abstract

Natural disasters can trigger chemical accidents resulting in fire, explosion or releases of hazardous material. Such conjoint accidents are known as Natechs (Natural-Technological accidents). Natural triggers such as earthquake; hurricane; flood; and the tsunami of Great East Japan in 2011 were documented in previous studies. In their works, they reported the severe consequences of the Natechs and investigated the specific features of scenarios. Moreover, Natechs threaten the lives and property of residents living close to the Natech hazards. For example, due to the Liquefied Petroleum Gas (LPG) leak during the Great Hanshin-Awaji Earthquake, 1995, 72,000 inhabits were recommended to evacuate. During the Kocaeli Earthquake, 1999, two Natech events in a refinery and a acrylic fiber production plant forced local authorities to evacuate the residents in a range of 5km of and 6km, respectively. Krausmann, et al 8) reported that during the Wenchuan earthquake, 2008, 6000 residents near an ammonia factory needed to evacuate due to the releases of ammonia and sulphuric acid, etc. Even evidence has already shown that the Natechs may require evacuating large number of residents in a large scale, the study with detailed analysis of evacuees’ behavior during a Natech is still limited. Natech events may harm population either directly or indirectly. Salzano et alindciated that the direct effects may include fire, spread of toxic clouds or toxic fumes, environmental pollution and other events difficult to control after the strike of a natural disaster. Indirect damage may be caused by the overloading of emergeny system, the loss of critical supply lines that may hider and delay the rescue and recover operations. Futhermore, during a Natech accident, people may need to evacuate more than once due to the simultaneous natural events and technological accident. To protect residents under such complex and uncertain situation, a detailed analysis of their evacuation behavior is required. With such information, emergency managers can develop efficient emergency plans to protect people under the risk of Natech accidents. In this study, we analyzed household evacuation behavior in terms of departure time, transportation use and the option of shelters. Data were collected from the randomly selected households within 2.5 km of the Natech accident occurred at a refinery in Sendai industrial park during the Great East Japan Earthquake and Tsunami (GEJET).