Spatiotemporal evolution and climbing curve simulation of land green use efficiency in urban agglomerations of China

[Objective] The aim is to reveal and validate the wave-like climbing pattern of land green use efficiency in urban agglomerations, providing decision support for promoting integrated enhancement of land green use efficiency and collaborative use of land resources within urban agglomerations. [Methods] Using panel data from 2006 to 2020, taking urban agglomerations of China as the research object, this study first analyzed the basic principles of the evolution of land green use efficiency in urban agglomerations based on the theories of urban functional interaction, spatial justice, and the adaptability theory of human-environment systems. Subsequently, methods including the non-expected output super-efficiency SBM model, joint intensity and threshold model, and numerical simulation were employed to explore the spatial-temporal characteristics and climbing patterns of land green use efficiency in these urban agglomerations. [Results] (1) The overall trend of land green use efficiency in urban agglomerations of China is upward, and spatially exhibiting a distribution of “higher in the north and south, lower in the middle, and higher in the west and lower in the east”; (2) The joint intensity of land green use between the central cities and neighboring cities continues to increase, with a threshold limitation. The process of central cities jointly arranging land green use with surrounding cities presents a step-like diffusion pattern from the central cities to the periphery; (3) The fluctuating climbing curve of land green use efficiency in urban agglomerations with the changes in time and the joint development of cities has been verified in practice, and the fitting is reasonable. [Conclusion] Cooperation between the central city and neighboring cities in the field of land green use of land resources in urban agglomerations should be strengthened. Clarifying the functional positioning of cities， through functional streamlining or aggregation, industrial chain integration, and the integrated development of industrial interactions can promote the formation of a high-quality development pattern of national land space.