Hierarchical Structure of the Central Areas of Megacities Based on the Percolation Theory-The Example of Lujiazui, Shanghai

The study of an urban center's hierarchical structure is an important subject if one wishes to understand the city. Previous studies on urban hierarchical structure focused mostly on qualitative or quantitative research based on factors such as format, transportation, and economy, and lacked quantitative measurement from the perspective of street networks. This study examined the urban central area of Lujiazui, Shanghai, from the perspective of the percolation of the street network in the urban central area. Then, combined with the actual urban space function, the connotation and fractal nature of the hierarchical structure of the central area of the mega-city were obtained. The resulting nested hierarchies represent a reorganization of these highly agglomerated urban centers that contribute to sustainability. The fractal results were verified by the box counting method. Finally, this study fulfills its main purpose, which is to propose a new method for the study of the hierarchical structure of urban central areas.