Mapping long-term urban–rural sprawl trajectories at 100 m spatial resolution: Austria’s transition from low to high sprawl, 1975–2020

Abstract

Urban sprawl—the decentralization of housing, employment, and economic activities into scattered, low-density settlement patterns—poses a major challenge to achieving SDG 11: Sustainable cities and communities. Yet, its long-term development trajectories remain insufficiently understood. We analyze sprawl by (1) integrating physical and social dimensions using building fractions and use-density; (2) tracing sprawl across the urban-rural continuum at 100 m resolution; (3) mapping long-term changes (1975–2020); and (4) applying a transition matrix to identify spatially explicit changes across periods. Using the Weighted Urban Proliferation (WUP) metric applied to the GHSL2023 dataset, we show that a large share of buildings-affected land in Austria transitioned from low to high sprawl, and that the expansion of buildings-affected land significantly outpaced population growth. We identify five periods of sprawl development and demonstrate that Austria falls far short of SDG 11 targets, particularly 11.3. The approach holds strong potential for multi-national comparisons and global upscaling.