Conceptualizing Multiple Hazards and Cascading Effects on Critical Infrastructures.

Despite increased research in "multiple hazards" and "cascading effects", there remains terminological ambiguity of the concepts. In this paper, we review the literature to explore how these two concepts are defined in relation to critical infrastructures and their vital societal functions. We then investigate how the concepts are operationalized in Swedish disaster risk management. Findings indicate that despite a wealth of methodologies assessing multiple hazards and their cascading effects, these are rarely used by local planners suggesting a gap between scientific approaches and practical implementation. Research mainly captures multiple hazards and cascading effects through technical parameters related to the severity of a hazard or the direct physical impacts on an infrastructure. Less focus has been placed on the wider or knock-on effects occurring across sectors and how these translate into societal risk. Future research should move beyond traditional understandings of social vulnerabilities as only pre-existing, to assess how cascading effects on infrastructure and services can put new social groups at risk.