Wildfires can pose risks to human settlement in three main scenarios. The first can happen when urban or suburban development borders wild land. The second happens  where homes or small communities are interspersed throughout a wild area, and the boundary between developed and non-developed land is undefined. The third occurs  where pockets of wild land are enclosed within cities.
Wildfires can pose risks to human settlement in three main scenarios. The first can happen at the classic wildland-urban interface, where urban or suburban development borders wild land. The second happens at the mixed wildland-urban interface, where homes or small communities are interspersed throughout a wild area, and the boundary between developed and non-developed land is undefined. The third occurs in the occluded wildland-urban interface, where pockets of wild land are enclosed within cities.
R
when
at the classic wildland-urban interface, where
A
at the mixed wildland-urban interface,
A
in the occluded wildland-urban interface,