Understanding and Preparing for Compound Flooding

The interconnected nature of climate-driven hazards poses significant challenges for risk management and disaster preparedness. Compound Flooding (CF) in estuarine and coastal regions exemplifies this complexity, where the interaction of drivers such as storm surges, extreme rainfall, and river discharge generates cascading impacts that traditional univariate assessments cannot fully address. As climate change accelerates the occurrence of CF, advancing methods to characterize these interactions and translating this knowledge into adaptive strategies is essential for reducing risks and building resilience.

This study combines a multivariate framework for estimating joint return periods with an exploration of preparedness strategies to address the intricate challenges posed by CF. Applied to the Santoña estuary in Northern Spain, it employs copula-based models to analyse dependencies among CF drivers and estimate joint return periods in a high-dimensional context. The analysis not only enhances our understanding of extreme events but also provides practical tools to improve risk assessments. Building on these findings, a systematic literature review examines the evolution of preparedness measures, highlighting advancements such as hybrid early warning systems and integrated infrastructure. However, persistent barriers—including fragmented governance, limited coordination, and insufficient consideration of behavioural and psychological factors—continue to constrain their effectiveness.

Together, these insights emphasize the need to rethink how to manage compound flooding—bridging governance gaps, fostering collaboration among scientists, policymakers, and communities, and integrating technical innovation with people-centered strategies. Such frameworks must not only respond to immediate challenges but also adapt to the evolving uncertainties that define the complex risk landscape of CF.

 

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