Urban expansion in China from a land price equilibrium perspective: regulatory theory and empirical study

Rapid urban expansion has brought growing pressure and challenges to the sustainability of urban development. Therefore, exploring urban expansion’s regulation and spatial optimization is essential, particularly in China. This study first characterized urban expansion at different levels. Then, the theoretical propositions and regulation strategies for urban expansion in China were proposed based on the price equilibrium principle. Finally, fusion method of nighttime lighting and remote sensing index, CA-Markov model, land price calculation model, spatial interpolation method were used to carry out empirical study in Xuzhou, China. This study shows that the globe saw rapid urbanization, and urban expansion had the characteristics of continuing “momentum proliferation” and the existence of “inertial boundary” and “inertial space.” In China, cities in the stage of rapid industrialization will continue to expand. Based on the land price equilibrium, the ideal, moderate, and limit boundaries of urban inertial space regulation in China can be defined. Using these boundaries in the inertial space to define three regulation zones, namely ideal regulation zone(IRZ), cost regulation zone(CRZ), and alert regulation zone(ARZ), can solve urban expansion regulation. Xuzhou’s IRZ, CRZ, and ARZ will be 65.91 km2, 66.57 km2, and 10.87 km2 in 2025, respectively. Xuzhou should choose the IRZ and CRZ with 133.48 km2 as the land space optimization reference system. This study can provide new insights into urban expansion regulation and spatial optimization to support sustainable and high-quality urban development.