Measuring urban sprawl and exploring the role planning plays: A shanghai case study

- We build a multi-dimensional index method of combining city expansion, urban compactness and urban form to measure urban sprawl.
- Urban sprawl presents spatial heterogeneity within different areas of the city.
- Analysis of Geo-Detector reveals that planning has played a key role of contributing to urban sprawl.

Measuring the degree of urban sprawl largely depends on the local context and available data. This research establishes a multidimensional index which combines city expansion, urban compactness and urban form to measure sprawl. Urban planning, as part of the state-led growth approach, has exerted dramatic impact on city growth in China. Recent studies have discussed the role of planning in city growth. However, measuring the impact of planning on sprawl, has not been conducted. Taking Shanghai as a case study, this paper builds a multidimensional index to measure the spatio-temporal characteristics of urban sprawl in Shanghai from 1990 to 2010. It finds that urban sprawl was more serious in 2000s than in the 1990s, and the sprawl also presents spatial heterogeneity within different areas of the city. While quantifying the role of planning in urban sprawl, this study adopts the Geo-Detector based on spatial variation analysis of the geographical strata in order to assess the impact of planning on urban sprawl. It finds that planning is strongly correlated with urban sprawl, in other words, urban sprawl is kind of a "planned sprawl" in Shanghai. The research concludes with future planning policies necessary for a more sustainable and compact development pattern.