Hotspots of the Wildland-Urban Interface in Africa

Africa's population has grown rapidly over the past century and is expected to more than double in size by 2100. As human settlements expand into wildlands, the risks of wildfire damage, human-wildlife conflict, zoonotic disease transmission and invasive species introduction are all increasing. The high-risk zone where buildings and wildland vegetation meet or mingle is the wildland-urban interface (WUI). The WUI has been mapped in many developed countries, and has become a management focus there, but WUI patterns remain unknown across much of the African continent. Our goal was to map the WUI at 10-m resolution across Africa and evaluate regional differences in WUI coverage. To delineate the WUI, we analyzed Copernicus Sentinel-2-derived land cover data and >600 million individual building locations. We found extensive WUI coverage in many parts of the continent: for example, in Zimbabwe, 48% of the country's land area and 94% of all buildings were within the WUI. Similarly, the WUI was widespread in East Africa (Burundi, Uganda, Rwanda, Kenya), West Africa (Benin, Cameroon and Nigeria), and the east coast of South Africa. Our results highlight the pervasiveness of WUI under different socioeconomic conditions, and are important for conservation planning, protected area management and wildfire risk reduction.