Spatial–temporal dynamics of urban green space in response to rapid urbanization and greening policies

Rapid urbanization has caused many environmental impacts associated with the reduction of green space. Having realized the important role of green space in urban ecosystems, many local governments in China have set out a series of policies to introduce green elements into urban areas. Insights into how urban green space changes in response to urbanization and greening policies are essential for guiding sustainable urban development. This paper employed integrated approaches to characterize the changing patterns and intensities of green space in Kunming, China from 1992 to 2009. Spatial variations of green space pattern were derived through concentric and directional landscape analyses integrated with landscape metrics. Change intensities of the two time periods from 1992 to 2000 and from 2000 to 2009 were calculated for the study area as a whole, the concentric belts, and the directional transects to examine the variation of the green space change rate in the city. Results revealed that both rapid urbanization and greening policies accounted for the process of green space change. Among the green space land use types, agriculture land was largely encroached and fragmented by urban sprawl, especially in the outer belts of the city. Forest land was also impacted but encountered a relatively moderate loss rate compared to agriculture land. Conversely, greening policies contributed to the recovery of grass land in the last decade. The study demonstrated the usefulness of the concentric and directional landscape analyses in characterizing the spatial–temporal variations of urban green space in cities with a concentric development form.

Research highlights
► Urban sprawl resulted in the loss of green space, particularly in the agriculture land while greening policies contributed to the recovery of grass land.
► Spatial variances in landscape patterns were detected in different concentric belts and directional transects.
► Change intensity varied among different types of green space in the context of urbanization and greening policies.