Spatial Interaction and Driving Factors between Urban Land Expansion and Population Change in China

The rational matching of urban land and population has become an important prerequisite for sustainable urban development. In this paper, the traditional urban land scale elasticity model was improved, and combined with the gravity model, the spatial interaction between land expansion and population change in 618 cities in China during the period 2006–2021 was investigated. The geographical detector method was used to reveal what drives them. The main results were as follows: (1) China’s urban land expansion rate was 1.83 times faster than the population growth rate during 2006–2021. After the implementation of the New-type Urbanisation Plan in 2014, the ratio of land expansion rate to population growth rate dropped from 2.46 to 1.12. (2) Among the six interaction types identified, land rapid expansion is the most significant, accounting for 41.59% of urban samples. (3) The geographical detector method found that the indicators of urban development rights such as the level of administrative hierarchy and the ratio of fiscal revenue to fiscal expenditure were the main factors affecting land expansion and that economic indicators such as gross domestic product and employment opportunities dominated population change. Fortunately, the intervention role of urban development rights has declined, and the constraints of market mechanisms, resources and environment have gradually become the dominant factors in urban land expansion and population change. These findings provide a theoretical basis for alleviating the human–land contradiction and achieving sustainable urban development.