An integrated relative risk assessment model for urban disaster loss in view of disaster system theory

Comprehensive risk evaluation of urban areas is important for disaster prevention and mitigation. Since disaster scenarios of urban areas are diverse and complex, the data are generally inadequate for understanding the absolute risk of disaster loss posed by any specific hazard or multi-hazards but adequate for identifying areas that are at relatively higher risk levels to some extent. Therefore, this paper focuses on modeling relative risk assessment for urban disaster loss. Based on disaster system theory, elements at risk and hazard-formative environments were determined as the crucial components to reflect risk discrepancies of different urban areas facing similar hazards. Furthermore, the critical path of interactions between components within the disaster system was constructed by introducing exposure and sensitivity as filtering processes. On this basis, a relative risk model for urban disaster loss assessment was constructed and applied to cities in Liaoning Province as an illustration. In addition, the results were represented and analyzed from multi-dimensions. A test for the uncertainties of the results indicates that this model shows a strong applicability for urban disaster loss relative risk assessment on the premise of accurate data concerning elements at risk and hazard-formative environments.