Archetypes of Compounding Impacts

Publication Year: 2025

Access: Open

Link: https://nhess.copernicus.org/articles/25/2751/2025/nhess-25-2751-2025-discussion.html

Author(s): Wiebke S. Jäger, Marleen C. de Ruiter, Timothy Tiggeloven, and Philip J. Ward

Organisation(s)/Authors:

Description:

Multiple hazards, occurring simultaneously or consecutively, can have more extreme impacts than single hazards. We examined the disaster records in the global emergency events database EM-DAT to better understand this phenomenon. We developed a method to identify such multi-hazards and analysed their reported impacts using statistics. Multi-hazards have accounted for a disproportionate number of the impacts, but there appear to be different archetypal patterns in which the impacts compound. We conceptualise four archetypes (“the whole is greater than the sum of its parts”, “the whole equals the sum of its parts”, “one part determines the whole”, and “the whole and the parts are limited by total impact”) to describe these patterns and to guide the integration of multi-hazard interrelationships into risk assessments. Across all archetypes, hazard pairs have at least as much impact as single hazards, but their impact can be higher than, comparable to, or lower than the combined impact of two single hazards. The uncertainties and limitations encountered in our study highlight the need for future research to improve data on multi-hazards and their impacts.

Technical Considerations:

Key Words:

multi-hazards, impacts