Analyzing the Vulnerability of Residential Buildings in the City of Chaitén: A Focus on an Extreme Event Scenario in a Disrupted River Corridor Following the Cataclysmic Volcanic Eruption of 2008

Abstract

Pillared on the hydrodynamic simulation of an extreme flooding scenario, we subsequently evaluated the physical vulnerability of residential buildings utilizing an ad hoc developed indicator-based methodology. This method aimed to quantify the expected loss for each affected residential structure. The outcome of this assessment facilitated the creation of a detailed risk map, allowing for the identification of hotspots that require immediate prioritization in mitigation efforts. The results of our study revealed a concentrated impact of the flood, particularly in the northern sector of the city. Within this region, four high-risk areas were pinpointed, comprising 70 homes predominantly situated close to the active channel zones. Notably, our findings underscored that twelve residential buildings, located at shorter distances from the river, are particularly susceptible to the impacts of the flood, as indicated by the physical vulnerability index values. It is important to highlight that the developed methodology is specifically tailored for the analysis of lightweight, one or two-storey houses with exteriors constructed from wood and zinc plates, as opposed to structures built with concrete or stone masonry. This distinction is crucial, given the prevalence of such building types in the Chilean Patagonian region. We recommend extending the application of this methodology to other urban areas in the region, where analogous impacts are possible and similar architectural patterns are common.