The wildland-urban interface as no man’s land in the construction of wildfire risk for Chilean coastal cities

Abstract

The impact of wildfires in wildland–urban interface (WUI) zones of central-southern Chile has steadily grown in recent decades, intensifying during the 2022–2023 season with 1,834 fires that burned more than 183,000 hectares in the Biobío Region. While most studies have focused on the Concepción metropolitan area, this article examines the case of Arauco, assessing wildfire threats and their relationship with the zoning established by the 1988 Municipal Master Plan (PRCA, in Spanish). Using a spatial analysis that integrated biophysical and anthropogenic variables, the study found that 60% of Arauco’s urban area has a high wildfire risk, and that over 75% of this surface is authorized for high-density residential uses by the PRCA. This overlap reveals that planning instruments not only overlook wildfire risks but also contribute to their social construction by promoting urban densification in highly exposed areas. The study concludes that the wildland–urban interface in Arauco, as in many coastal Chilean cities, remains largely unregulated, shaped by regulatory obsolescence, institutional fragmentation, and the absence of explicit risk criteria, effectively converting these areas into “no man’s lands.”