Application of a multi-hazard risk assessment for local planning

Multi-hazard assessments are increasingly vital to communities as exposures continue to change. Their data can provide a nuanced understanding of hazard interactions and their contribution to risk reduction. In previous work, the Patterns of Risk using an Integrated Spatial Multi-Hazard (PRISM) approach produces composite measures of vulnerability and risk at the county level for this purpose. The approach has the flexibility to be applied at a local level to benefit hazard vulnerability assessments and community sustainability planning activities. In this article, we use U.S. census tracts as proxy for neighbourhoods for a localized PRISM approach. The goal is to demonstrate the applicability of the PRISM approach at the community level and identify vulnerabilities in social, cultural, economic, and built systems for use in comparative analyses and mitigation planning. Exposure estimates are created using spatial extents and modelled data from 12 natural and 4 technological hazards. Land area, population counts, and property values are used to estimate vulnerability. National patterns of exposure, vulnerability, and risk reveal distinct regional trends that point to the importance of how impacts are defined. Eight case study examples demonstrate how the data can be analyzed to compare drivers of community vulnerability and risk.