Archetypes of Compounding Impacts from Multi-Hazards

Compounding impacts from multi-hazards - where two or more hazards occur close together in space or time – are increasingly recognized as an important component of disaster risk. More than half of the reported impacts (economic damages, people affected and deaths) in global disaster records can be classified as compounding impacts.

Recent analyses of global disaster records, such as EM-DAT and DESINVENTAR, indicate that compounding impacts tend to exceed those of single-hazards (Xu et al., 2024; Jäger et al., 2025; Worou and Messori, 2025). However, we still lack a clear understanding of how these compounding impacts differ from the component-sum impacts of their individual hazards’ constituents. In Jäger et al. (2025), we also conducted a statistical comparison of observed impacts from hazard pairs and synthetic combinations of individual hazards, suggesting different patterns in how impacts compound, depending on hazard types and the impact metrics. To make these patterns easier to understand and use in risk assessments, we conceptualized four archetypes of compounding impacts: cases where impacts exceed the component sum, match the component sum, are dominated by one hazard, or are limited by overall system constraints.

Here, we present ongoing work to refine, substantiate, and operationalize these archetypes using evidence from peer-reviewed and grey literature. In doing so, we aim to move toward a structured framework to guide both research and practice in assessing compounding impacts from multi-hazards.