Modeling potential fire spread polygons and networks for suppression strategies

Unprecedented fire seasons are overwhelming fire suppression capacity in Mediterranean Europe. Fire services respond to urgent risks, but are being outpaced by more complex wildfires. Fire suppression needs proactive and risk-informed strategies to avoid catastrophic wildfires. In this study, we present an automatic method for generating potential fire polygons by adapting hydrological basin delineation techniques to fire spread simulations. Using the time since ignition as input, we segment the landscape into polygons representing discrete spatial units of fire potential. These polygons are then connected into a spatial network, where edges are characterized by penetration rate of spread – a novel metric weighted by the spatial extent of fire spreading between polygons. We apply this method in the field during two major wildfires in Catalonia (Spain) during the 2024 fire season. In the Ciutadilla fire driven by wind, our approach identified high-risk polygons and fire pathways that closely aligned with real suppression actions. In the Vilanova de Meià fire, we implemented different scenarios and modeled their fire potential networks. We demonstrated how proactive tactics and prescribed burn significantly delayed fire progression. Reactive tactics provided minimal benefit. Our approach automates the traditionally manual process of drawing fire potential polygons. In addition, fire potential networks provide crucial information in relation to risk on high-risk polygons, major fire pathways, and potential fire openings. As wildfires continue to threaten our built and natural environments, the proposed method can be integrated into risk-based frameworks to streamline fire management and support proactive strategies.