A longitudinal study of evolving polycentric pattern in Shanghai

In the context of technological progress and economic transition, the urban spatial structure has consistently undergone dynamic evolution. However, the trajectories of polycentric patterns display significant national and regional variations. It is crucial to examine the dynamic evolution of spatial structures within Chinese metropolitan areas amidst economic transitions. Focusing on the Shanghai Metropolitan Area (SMA), this study investigates the temporal dynamics of job distribution and employment centres and considers industry differentiation to understand the evolution of polycentric patterns. Additionally, spatial regression models are utilized to probe the intrinsic mechanisms through which adjustments in industrial structure influence spatial evolution. The findings indicate that both the service and manufacturing sectors have the potential to concentrate employment and form subcentres in the SMA. Nevertheless, within the economic transition context, the downtown area, dominated by the service sector, underwent specialized development, fostering continuous prosperity and the emergence of employment subcentres in the periphery. In contrast, employment centres in suburban areas, dominated by the manufacturing sector, experienced a declining trend. Consequently, the locations of employment clusters in the SMA shifted, concurrently reshaping the relationships between the main centre and subcentres and leading to a transformation from a weaker separated polycentric pattern to a stronger continuous polycentric pattern. This paper elucidates the underlying mechanisms through which industrial transition influences urban spatial structure, offering insights into the evolution of polycentric patterns in the postindustrial era from a local Chinese perspective.