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College of Arts & Sciences
Hazards & Vulnerability Research Institute

Conjoint Disasters in South Carolina: The Threat of Tornado-Induced Hazardous Material Releases at TRI Facilities

Angela M. Nelson

Advisor:  Dr. Susan L. Cutter



Tornado forces can trigger a hazardous material release.  Surprisingly, little research has been conducted on technological disasters resulting from natural hazard events, particularly tornados.  The principal goal of this research is to examine the potential impact of such conjoint disasters upon populations surrounding TRI facilities in South Carolina.  A Geographic Information Systems (GIS) was used to store and manipulate spatial data pertaining to point locations of major facilities as well as historic tornado touchdowns (1950-2004).  A statistical model – the conjoint disaster model – was generated to assess the relationship between historic tornado events, social vulnerability, and potential risk of exposure at TRI facilities.  Tornado frequency values were assigned to each facility based on spatial location, and represented the potential for damage to occur.  Chemical exposure scores were calculated for each chemical on-0site.  Lastly, a statistical index was created from ten different demographic variables to measure the social vulnerability of host communities (block groups containing TRI facilities).  This model ranked all TRI facilities in the state according to the danger they pose to human population.  After comparing community demographics for all TRI and non-TRI block groups, it was determined that environmental inequity does not exist for the tornado-hazmat burden in South Carolina.  This research provides an applicable methodology for emergency management plans to assess the threat of conjoint disasters.