Urban Green Space in Shrinking Cities

Do shrinking cities actually use the green space they have? Green space matters for residents’ health and for equitable development, and in cities losing population it is often framed as a tool for restoring vitality. But most earlier work on green space and regeneration relies on cross-sectional data, which misses change over time and the many underused parks common in North American shrinking cities.

This study examines Pittsburgh, a city that has shrunk severely. We used machine learning on satellite imagery from 2019 to 2022 to track changes in the distribution, area, and morphology of urban green space, paired that with census-tract visitation data, and ran ordinary least squares and Geographically Weighted Regression to test how green space relates to community vitality. Two patterns stand out. First, larger green spaces within a tract are associated with higher visitation, while larger green spaces in the surrounding 500-meter radius pull visitation down. Second, land use matters: small green spaces in the CBD are used far more intensively than large, underused ones around low-density facilities like hospitals and schools. For planning in shrinking cities, the quality of green space deserves as much attention as its quantity.

This work was presented at the ACSP 2024 Annual Meeting in Seattle, Washington.