Abstract
<title>Abstract</title> <p>Coastal wetlands act as vital bioshields against tsunami hazards, yet rapid urban sprawl and densification threaten their capacity to enhance community resilience. This study evaluates the contribution of coastal wetlands to tsunami resilience in Chilean metropolitan areas by analyzing the interplay among Anthropization, Mitigative-Adaptive Characteristics, and Conservation-Governance Initiatives through a mixed-methods approach. We first mapped wetlands using GIS and then developed and validated 17 variables based on empirical evidence, an expert panel, fieldwork, open databases, and spatial analysis. Finally, we performed correlation and reliability analyses to create the Wetland-Based Urban Resilience Support Index (WURSI). The application of WURSI in the study areas indicates that high anthropization and wetland scarcity limit current mitigation capacity, underscoring the urgent need for Nature-Based Solutions to complement passive conservation. Furthermore, the analysis shows that, while emerging legal protection frameworks face intense opposition from private-sector actors, civil society and NGOs serve as critical governance actors that help fill institutional gaps. Ultimately, WURSI provides an adaptable framework for coastal cities worldwide to assess critical trade-offs between wetland conservation, urban development, and tsunami resilience.</p>