Analysing historical disasters to support multi-hazard risk assessment: enhancing forensic analysis through Impact Chains

Analysing past disaster events is essential for advancing our comprehension of the complex interactions among risk factors and the subsequent cascading impacts. Assessing the direct and indirect consequences of past events and the reasons why these occurred can help estimate the impacts and losses for future events as well as pinpoint risk mitigation measures. Although forensic analysis investigation aims to address disasters and tackle the root causes comprehensively, a systematic method is still needed to represent the interplay among diverse risk factors and enable a cross-cutting and quantitative analysis of disaster databases.

Impact chains provide a clear and intuitive conceptual representation of risk, the interaction among their elements (hazard, exposure, and vulnerability) and their cascading impacts.  Highlighting the type of relation between the risk elements, impact chains explicitly consider risk mitigation and climate change adaptation measures and aim to integrate multiple data collections and analytical approaches. This interdisciplinary approach enables a more holistic analysis of disaster events, providing a structured framework to identify past weaknesses and deficiencies, thereby enhancing strategies for disaster risk management and fostering improvements in disaster databases.

Our research aimed to explore the potentialities of impact chains for analyzing historical disaster events, including how this method can support the forensic analysis approach in the context of compounding events. We pursued the following goals: (i) to develop a multi-hazard impact chain from historical disaster events, (ii) to collect the disaster data based on the impact chain developed in order to analyze the interrelationships between the risk components, and (iii) discuss how the results can support the forensic analysis approach.To accomplish this objective, a diverse set of disaster events were analysed. These events are characterized by being multi-hazard, having a significant impact, and covering a diversity of sectors, geographic locations, and scales (Romania, Turkey, the Caribbean, the Alps, etc.). These analyses were carried out under the PARATUS project.

Preliminary results showcase the significant potential for using this method to develop more comprehensive impact chains, particularly when representing multi-hazard events. One of the key achievements identified is that this approach emphasizes the role of vulnerability and the underlying risk drivers in the overall assessment.   The subsequent phase of this study focuses on enhancing the disaster databases by collecting data for the different elements included within the impact chain. This undertaking aims to facilitate a quantitative analysis of available data, scrutinize the interconnectedness of variables, and elucidate how these variables influence overall risk. Finally, through this comprehensive approach, we aim to provide valuable insights into the field of disaster research and management, fostering a deeper understanding of potential disaster risks and impacts and planning risk reduction measures accordingly.