Forensic insights into Gloria's storm multi-hazard damages in Catalonia

Conducting a forensic analysis of catastrophic multi-hazard episodes is a challenging yet essential undertaking to enhance our understanding and preparedness for future events. In this study, the multiple direct damage costs for repairing and replacing the effects of the Gloria storm, which struck Catalonia from January 20 to 23, 2020, are thoroughly examined. The storm, characterized by persistent and intense rainfall coupled with strong winds, resulted in a significant sea-level rise heightened by large waves, numerous slope failures and widespread pluvial and fluvial floods, leading to substantial direct economic losses. While databases of damage and losses provide valuable insights into documenting disaster effects, we propose an integrative approach that combines post-event data compilation with forensic analysis to understand the hazard conditions. The resulting database in our study includes parameters such as geographical location, triggering hazard, exposed element at risk, and cost, providing a comprehensive understanding of the Gloria storm's impact. By interpreting the collected data, we derive with key insights of the economic impacts and severity of the hazards caused by the storm in Catalonia. The compilation of data from 14 different sources revealed extensive repair and replacement costs of approximately 390 million Euros for the damages caused by the Gloria storm. Fluvial and coastal processes were the primary contributors to direct economic losses in Catalonia, with fluvial hazards accounting for 44% and coastal processes for 41%. Slope failures and meteorological hazards accounted for 9% and 5%, respectively, in the overall damages. By complementing this with forensic analysis, the integrated approach allows us to discern how and why these events occurred, whether they were amplified or diminished by management strategies, and what strategies could be applied. Additionally, the study incorporates the development of an impact chain, illustrating potential sequences of events and relationships based on the Gloria Storm case. This analytical diagram serves to better comprehend the interrelationships and cascading effects of different hazards, as well as the environmental and socio-economic factors contributing to the damages. The integrated approach contributes to more effective risk management strategies and enhances the broader field of disaster analysis.