The influence of structure locations on wildfire perimeters.

Primary Author: Joshua Olsen

Faculty Sponsor: Jonathan Yoder


Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Agricultural and Natural Resource Sciences

Campus: Pullman





Wildfires suppression in the United States has cost an average of $1.8 billion annually over the past 10 years and wildfire damages have frequently exceeded 10 times that amount. A major reason for the extreme cost of wildfires is the presence of man-made structures.


Despite the large associated cost, the influence that structures have on wildfire spread has yet to be evaluated. We address this gap by analyzing structure density around fire perimeters to understand the relationship between structures and wildfire spread.



Using an innovative dataset we evaluate structure presence around wildfires at a finer scale than has previously been possible. We analyze the present of structures per 1,000 acres across a 32 year timespan in the Western United States.



We find that a disproportionate number of structures reside in a 120 meter bandwidth around fire perimeters. We also find that structure density is highest in the first 30 meters outside of fire perimeters, suggesting that structures are more likely to be found immediately outside fire perimeters than inside fire perimeters. Structure locations are determined prior to fire ignitions which implies that structure locations influence final fire perimeters.

This trend is consistent across all 11 Western United States. This finding has implications for land development policy as well as policies governing prioritization for firefighting resources. For example, our results suggest that current fire suppression is largely guided by the presence of structures. This implies that structure protection may be prioritized over minimizing fire growth.