The global wildland-urban interface

Area of Science:

• Environmental Science, Geography, Remote Sensing, Urban Planning

Background:

• The wildland-urban interface (WUI) is a critical zone of human-environmental interaction, posing risks like wildfire, habitat loss, and disease spread.
• Previous global analyses of the WUI were lacking, hindering a comprehensive understanding of its extent and impact.

Purpose of the Study:

• To create a high-resolution global map of the WUI for the year 2020.
• To identify global WUI hotspots and analyze population density, land cover, and biomass variations within these areas.
• To assess the proportion of populations living in the WUI and near wildfire events.

Main Methods:

• Development of a globally consistent and validated approach using remote sensing-derived datasets.
• Utilized 10m resolution data for building area and wildland vegetation mapping.
• Analysis of population distribution and proximity to wildfires (2003-2020).

Main Results:

• The WUI is a global phenomenon, covering 4.7% of land but housing 3.5 billion people (nearly half the global population).
• Identified numerous previously undocumented WUI hotspots with diverse population densities, land covers, and biomass levels.
• Europe (15% of land area) and temperate broadleaf/mixed forests (18%) show widespread WUI. Two-thirds of people near wildfires live in the WUI, with 150 million in Africa.

Conclusions:

• The WUI is a significant and widespread global feature with substantial human populations at risk.
• Climate change-induced increases in wildfire activity necessitate understanding housing growth and vegetation patterns within the WUI.
• This global WUI map provides a crucial baseline for future research, policy, and risk management strategies.