A holistic asset-level modelling framework for a comprehensive multi-hazard risk/impact assessment: Insights from the ICARIA project

The frequency and intensity of climate- and weather-related phenomena have significantly increased over the past two decades, with future projections suggesting further escalation due to climate change. Compound events, involving coincident or consecutive hazards, and their cascading effects, often exacerbate the severity of disasters, resulting in greater damage than would result from isolated hazards. However, risk/impact assessments have predominantly used single-hazard approaches, limiting understanding of how multi-hazard interactions affect socio-eco-technological systems. This paper presents a comprehensive asset-level modelling framework developed within the EU-funded Horizon Europe project ICARIA. The framework aims to assess risks/impacts and resilience to a wide range of natural phenomena, including droughts, heatwaves, extreme winds, wildfires, floods and landslides, as well as the potential cascading effects due to impacts on interdependent infrastructure systems. It enables the development of multi-hazard scenarios, data harmonisation, and the characterisation of exposure and vulnerability for different categories of elements at risk, particularly critical infrastructures and related services, thereby facilitating the estimation of direct and indirect damage. Furthermore, the framework incorporates coping, adaptive and transformative capacities as key-components of resilience, as well as human behavioural factors, into the modelling process. Examples from initial testing of the framework on ICARIA case study regions are introduced to highlight the operational steps for its application, including the identification of reference multi-hazard risk/impact scenarios through event trees, the inventory of relevant modelling data and the interconnection of single hazard/impact models to determine the consequences of complex multi-hazard events on exposed assets and services.