Time Series Mapping of Global WUI Areas from 1985 to 2020

Intensifying wildfires and human settlement expansion have placed more people and infrastructure at the wildland–urban interface (WUI) areas under risk. Wildfire management and policy response are needed to protect ecosystems and residential communities; however, maps containing spatially explicit information on the distribution of WUI areas are limited to certain countries or local regions, and therefore global WUI patterns and associated wildfire exposure risk remain unclear. Here, we generated the global WUI data layers for 2020 baseline and 1985-2020 time series by incorporating fine-resolution housing and vegetation mapping. We estimated the total global WUI area to be 6.62 million km2. Time-series analysis revealed that global WUI areas experienced a substantial increase of 12.56% between 1985 and 2020. By overlapping 2001-2020 wildfire burned area maps and fine-resolution population dataset, our analysis revealed that globally, 7.07% (12.54%) of WUI areas housing 4.47 million (10.11 million) people are within a 2400-m (4800-m) buffer zone of wildfire threat. Regionally, we found that the United States, Brazil, China, India, and Australia account for the majority of WUI areas, but African countries experience higher wildfire risk. Our quantification of global WUI spatiotemporal patterns and the associated wildfire risk could support improvement of wildfire management.