Combining physical and social indicators in a multi-vulnerability framework for fire risk assessment: An application to Valparaíso, Chile

Over the years, global concern regarding fire prevention in historic urban areas has grown considerably. These areas possess significant cultural, urban, architectural, and social value, but also exhibit a range of intrinsic characteristics that render them highly prone to fire ignition and propagation, thereby posing significant challenges for fire control. Valparaíso, a UNESCO World Heritage Site, is one of the best examples of this: its historic area lies between the bay and a series of hills, forming a unique configuration of buildings, stairways, roads, and lifts. The area’s vulnerability is exacerbated by a high fire load associated with construction materials, a dense concentration of buildings, and sloping terrain that is particularly exposed to prevailing winds. Additionally, the narrow configuration of the urban street layout adds further complexity to fire-fighting operations and hinders the evacuation of affected individuals. In light of these challenges, there is a clear need for comprehensive and context-sensitive tools that can effectively assess and communicate fire risk in such complex urban environments. This paper aims to contribute to filling this gap by introducing an integrated approach to fire risk assessment of historic urban centres, innovatively incorporating and combining physical and social dimensions. Two index-based methodologies are proposed, underpinned by an analysis of CENSUS data at the block level – an approach that is rarely addressed in existing literature. The outcomes of these indices are consolidated within a prioritisation matrix that is applied to categorise the city blocks into five priority levels. A Geographic Information System (GIS) tool is subsequently utilised to spatially visualise and map the risk classification results.