There is growing evidence that technological disasters can be triggered by natural disasters, and that these conjoint events ("na-techs") can pose tremendous risks to regions which are unprepared for such disasters. Recent examples include the catastrophic refinery fires at the Tupras oil refinery following the August 1999 earthquake in Turkey, the releases of hazardous materials which resulted from the 2001 Bhuj earthquake in India, and the damage inflicted on industrial facilities during the European floods of 2002. Recognizing the need to understand the risk posed by na-techs in the United States, this project will generate and analyze the record of conjoint disasters over the last twenty-two years in the United States. Using a variety of data sources, including mail surveys of emergency managers, EPA and FEMA databases, and telephone and on-site interviews, we will determine the incidence of na-techs disasters over the twenty-two years, the types of natural hazards which triggered them, the failure modes of the hazardous materials vessels/equipment, the industries which have been vulnerable to these releases, and the on and off-site consequences of the releases. From these data, we will construct conditional probabilities of a technological disaster occurring, given that a natural hazard occurs. For a selected subset of US counties, we will show how these conditional probabilities can be used to construct probabilistic GIS-based maps showing the total probability of na-techs occurring in specific counties. In addition, case studies of individual na-techs in the United States will be developed and the results synthesized so that general conclusions can be drawn regarding vulnerability of hazardous materials to release as a result of natural disasters, mitigation measures needed to prevent or minimize the impact of such releases, and appropriate response measures in case of a release. These case studies will also be useful as data from which expert judgment can made regarding the potential for catastrophic technological disasters as a result of natural hazards.
