Spatial and temporal dynamics of urban sprawl along two urban–rural transects: A case study of Guangzhou, China

Detailed understanding of landscape changes along the urban–rural gradient provides a useful tool to compare the structural and functional differences of landscape patches at different orientations. Although several case studies have been conducted confirming the efficacy of this approach, integrating temporal data with gradient analysis is still rarely used in practice. In this study, a combination of remote sensing images, landscape metrics and gradient analysis are employed to analyze and compare both the spatial and temporal dynamics of urban sprawl in Guangzhou, China. The results show that landscape change in Guangzhou exhibits distinctive spatial differences from the urban center to rural areas, with higher fragmentation at urban fringes or in new urbanizing areas. Due to the complexity of top-down constraints and local interactions, Guangzhou exhibits a more complex, dynamic, multidimensional configuration of urban sprawl that is different from other cities in China. Urban area expanded towards the north and south areas due to the increased population and rapid economic development. Property market forces and government policy led to the rapid growth towards the southern areas. The study also confirms the hypothesis of diffusion-coalescence urban dynamics model in the process of urbanization. It demonstrates that in order to reveal the complexity of landscape pattern, temporal data are needed to capture the baseline as well as the spatio-temporal dynamics of landscape changes along the gradient. Combining temporal data with gradient analysis can characterize the complex spatial pattern of urbanization in Guangzhou well.