How to Approach the Definition of WUI in Northern Europe

This article aims to delineate the wildland–urban interface in the sparsely populated, limited-resourced Scandinavian peninsula (excluding Finland). Common WUI mapping assumptions and how different thresholds capture the reality of building ignition from wildfire in this region are evaluated. We show that dedicated fuel maps capture areas at risk slightly better than vegetation maps, although the choice of map per se is less important than the selected limit for possible ember transport. The commonly used 6.17 buildings/km² threshold for building density fails to capture most wildfire incidents that have led to building ignition.