Large Wildfire Patterns in the Wildland-Urban Interface of the Eastern U.S.

Wildfires are increasing in the eastern United States. The wildland-urban interface (WUI), which occurs at the intersection between human development and wildland vegetative fuels, remains the focus for predicting and mitigating wildfire risk. Wildfires in the WUI require more resources to suppress, destroy more homes, and pose a greater threat to human life. The eastern U.S. contains a disproportionately large amount of the WUI compared to other parts of the country, making it crucial to characterize differences between WUI and non-WUI wildfire regime changes. We contrast spatial and temporal characteristics of WUI versus non-WUI wildfire regimes across Level III ecoregions in the eastern U.S. using decadal WUI maps from 1990 to 2020 combined with large wildfire perimeter data and ignition source data from 1986 to 2021. We found that a substantial proportion of wildfires occurred in the WUI (45%), even though the WUI only makes up 22% of the eastern U.S. by area. The number of wildfires, mean area burned, and total area burned increased both inside and outside the WUI in most ecoregions. The primary source of wildfire ignitions in the WUI was arson and, secondarily, natural causes (lightning). The results of this study highlight the increasing risk of large wildfires in the eastern U.S. and can be used to help support informed decision-making surrounding wildfire risk management in the region.

International Association for Landscape Ecology - North America Annual Conference