Succession process and spatial expansion of old urban central zones: Shanghai, China

As the size and population of a city continue to increase, the old urban central zone undergoes constant spatial expansion and structural evolution, which show different characteristics and corresponding patterns in different stages. However, how does this process happen, what factors affect it and what characteristics does it have in different stages? These problems are related to the mechanism of urban spatial growth and succession. This study focuses on the old urban central zone called People's Square Central Zone of Shanghai, China as a case study to examine the succession process from its formation up to now. This paper defines the boundary of the urban central area and hard cores (display central business characteristics in its purest form) in different periods through the Public Service Facility Index Method (defining the boundaries of the central area with the intensity of public service facilities), and makes a comparative study of its spatial structure. The old urban central zone evolved from a single-core expansion to circle-core differentiation and then multi-core development and its structural changes were theoretically reconstructed, while also analysing its typical spatial expansion patterns. Understanding the rules and characteristics of the succession process can be useful for future renovations of old urban central zones.