Layered or simple: Making impact chains more accessible and useful to stakeholders

Multi-hazard disasters underline the need to shift from siloed Disaster Risk Reduction and Management (DRR/M) policies and practice to coordinated, multi-hazard strategies and increased stakeholder engagement. The challenge lies in designing models and tools that accurately convey the intricacies of multi-hazards, compounded impacts, vulnerabilities, and mitigation actions without overwhelming users, thus preserving the clarity needed for effective decision-making. Addressing this critical implementation gap, this study introduces Layered Impact Chains and Simplified Impact Chains as frameworks designed to streamline stakeholders’ understanding of Impact Chains. Layered Impact Chains break down the complete model into layers comprising elements and connections relevant for various stakeholder categories, while Simplified Impact Chains distil these layers to their essential components using a custom statistical metric. The proposed frameworks are applied in a case study featuring a multi-hazard event relevant for Bucharest, Romania, wherein a major earthquake would set off a cascade of secondary hazards, including a dam-break flood, fires, and liquefaction. The foundational complete multi-hazard Impact Chain was built collaboratively, integrating insights from a wide group of DRR/M stakeholders via one-on-one interviews, focus groups, and hybrid workshops. The proposed Layered and Simplified types were subsequently validated in terms of understandability, navigability, and usability through dedicated workshops and focus groups with the target stakeholders. By translating complex disaster analysis models into accessible formats, the proposed frameworks empower stakeholders to understand multi-hazard disasters and craft integrated and more effective DRR/M solutions. • Layered Impact Chains facilitate stakeholders’ understanding of complex models. • Simplified Impact Chains reduce stakeholder-dedicated layers to their essence. • Both frameworks are co-developed and validated by DRR and DRM stakeholders. • These proposed frameworks promote stakeholder engagement in creating DRM tools.