From Night Lights to Wildfire Risk: Uncovering Human Exposure in a Mediterranean Hotspot

This study examines the evolution of human exposure to wildfires in Catalonia, Spain, over the period 1992–2021, by integrating geospatial data on fire perimeters, population, satellite-derived nighttime light (NTL) imagery, and settlement records. Although the burned area shows a slight statistically non-significant decrease (-0.43 km²/year), human exposure per unit of burned area has risen by 42% to 138%, depending on the buffer distance and dataset used. This alarming trend is mainly driven by rapid urban expansion and population redistribution, particularly in coastal regions, which highlights a growing intersection between human settlements and fire-prone areas. Our findings emphasize the critical role of urbanization in amplifying wildfire risks, underscoring the urgent need to integrate demographic dynamics into fire risk management strategies. By employing innovative proxies such as nighttime light data alongside high-resolution population and building density datasets, this study provides a comprehensive framework to assess wildfire exposure in rapidly urbanizing Mediterranean environments.