Human Exposure to Wildfires in Mediterranean Environments: A Case Study from Catalonia (1992–2021)

The Mediterranean region is one of Europe’s most fire-prone and vulnerable areas, facing compounding risks from urban expansion and wildfire activity. This study examines the evolution of human exposure to wildfires in Catalonia, northeastern Spain, over three decades (1992–2021). Using high-resolution geospatial data, including fire perimeters, nighttime light (NTL) intensity as a proxy for human activity, population data, and historical settlement patterns, we analyze trends in exposure per unit of burned area (BA). Results reveal a 77% increase in human exposure per unit BA, driven by population redistribution and urban expansion into fire-prone areas, despite a non-significant decrease in BA of −0.43 km²/year.

A novel aspect of this research is the integration of NTL data to capture dynamic changes in human activity and exposure, validated against population and settlement datasets. Exposure trends were assessed using counterfactual scenarios to isolate the impact of population dynamics. Findings underscore the critical need to account for human activity changes in wildfire risk assessments, highlighting the increasing vulnerability of expanding urban landscapes in Mediterranean regions. These insights are essential for developing adaptive and proactive wildfire management strategies to mitigate future risks.

This methodology provides a replicable framework for assessing wildfire exposure in diverse geographical contexts, emphasizing the value of integrating population dynamics with environmental datasets.

This work is currently in preparation.

Acknowledgements:
This work was supported by the project ‘Climate and Wildfire Interface Study for Europe (CHASE)’ under the 6th Seed Funding Call by the European University for Well-Being (EUniWell). M.T. acknowledges funding by the Spanish Ministry of Science, Innovation and Universities through the Ramón y Cajal Grant Reference RYC2019-027115-I. M.A.T-V and M.T acknowledge funding through the project ONFIRE, Grant PID2021-123193OB-I00, funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. AP acknowledges the support of the EU H2020 project “FirEUrisk”, Grant Agreement No. 101003890. The authors thank the Generalitat de Catalunya for access to fire perimeter data and Xavier Castro from the Forest Fire Prevention Service of the Generalitat de Catalunya for the helpful discussions on the matter.