An Analysis Method of Quantitative Coupling Rationality between Urban–Rural Construction Land and Population: A Case Study of Henan Province in China

Scientifically measuring the quantitative coupling relationship between urban–rural construction land (URCL) and population and formulating URCL utilization countermeasures are needed for protecting cultivated land resources, intensive utilization of land resources, and sustainable socioeconomic development. This study proposed an improved transition process theory of URCL and population and a coupling model of polar coordinates. Then, the coupling model was applied to Henan Province in China to analyze the coupling relationship between URCL and population, showing that the coupling relationship between URCL and urban–rural population (URP) in the province was unreasonable. However, the coupling rationality between rural construction land (RCL) and rural population (RP) had a significant improvement tendency. Furthermore, the coupling relationship between URCL and the population of prefecture-level cities in Henan province was analyzed, and the coupling model of polar coordinates proposed in this study achieved satisfactory results. Thus, compared with the commonly used Tapio’s decoupling model of elasticity, the coupling model further extends the concept of coupling analysis to the coupling type, coupling strength, and coupling rationality. The extension makes the measurement of the quantitative coupling relationship between URCL and population more scientific, comprehensive, and accurate.