Tornado papers A Tornado Scenario for Barrie, Ontario David A. Etkin (corresponding author) Adaptation and Impacts Research Group, Environment Canada Soren E. Brun North Carolina Dep’t. of Transport GIS Unit Solomon Chrom Faculty of Environmental Studies, York University Pooja Dogra Institute for Environment Studies, University of Toronto July 2002 ICLR Research Paper Series – No. 20
A natural disaster occurs when an environmental extreme triggers social vulnerabilities. The magnitude of the resulting impact is then a function of the intensity of the environmental extreme coupled with a society’s perception and adaptation to the hazard (Blaike et al., 1994). An examination of risk should therefore be composed of two parts: one part relating to the probability of a natural hazard occurring, while the second relates to the magnitude of the resulting impact (which depends upon the vulnerability of the exposed infrastructure and population). Various studies such as Hague (1987), Paul (1995a,b), Etkin et al. (1995; 2001), Paruk and Blackwell (1994) and Newark (1983), have explored the probability of tornado occurrence in Canada; while other (Lawrynuik et al, 1985; Allen, 1986, Carter et al., 1989; Charlton,et al., 1998) have discussed the impacts of individual Canadian tornadoes. Globally, Canada ranks second, after the United States, in tornado risk.
The purpose of this paper is to focus on the second part of the problem - that is, the impact/vulnerability aspect. In order to accomplish this, this paper will briefly review historical tornado impacts, consider one tornado disaster in more detail (the May 31, 1985 Barrie Tornado), and consider a hypothetical scenario of how it might have been worse, had events transpired somewhat differently (ie. create a worse case scenario).