The spatio-temporal trends of urban green space and its interactions with urban growth: Evidence from the Yangtze River Delta region, China

The role of urban green space (UGS) in urban sustainability is attracting increasing attention from researchers. How to achieve greener cities in urban development is an urgent problem to be solved. In this study, we investigate the spatio-temporal variation of UGS and its relationship with urban growth in different socio-economic development phases based on an empirical analysis of cities in the Yangtze River Delta region in China during a period of rapid urban development (2001–2019). The remote sensing data reveal a changing UGS pattern that declined notably in the first decade and has increased slightly since 2012, with the green areas mainly clustered in urban centers. We use piecewise linear regression to investigate the impacts of urban growth on UGS from the perspective of growth in the economy, population, and land — in four socio-economic development phases. The results show that the growth of the economy and population reduced UGS in the initial stage of development. Recently, there is more awareness of the importance of environmental issues in socio-economic development. Further, the growth of the economy and population could promote UGS in recent years. Meanwhile, the expansion of urban land boundaries could provide more spaces for UGS. However, the growth of urban land is contrary to the sustainable and compact development of the city. Finally, we discuss the potential of urban growth to improve urban environment, and propose nature-based solutions to mitigate the conflicts between urban compactness and UGS layout. This study supplements the theory of urban growth and the environment with evidence from Chinese cities and offers insights into sustainable urban development in developing regions.