Dynamic Evolution, Spatial Differences, and Convergence of Land Green Use Efficiency in Resource-based Cities

［Objective］ To reveal the spatiotemporal evolution, distribution dynamics, spatial differences, and convergence characteristics of land green use efficiency in resource-based cities, in order to clarify the land use status, optimize the national spatial development pattern, and provide a reference for comprehensive green transformation of economic and social development. ［Methods］ Based on data from 114 resource-based cities in China from 2006 to 2020, the spatial and temporal characteristics, distribution dynamics, spatial differences, and convergence features of land green use efficiency in resource-based cities were analyzed by using the super efficiency SBM model to measure land green use efficiency, in combination with Kernel density estimation, Dagum Gini coefficient, coefficient of variation, and fixed effects model. ［Results］ 1) Overall, the land green use efficiency in resource-based cities showed a fluctuating upward trend, with an average annual growth rate of 1.363% during the investigation period. From a regional perspective, the land green use efficiency showed a pattern of regional differences in most years, with the eastern region>northeast region>central region>western region. From the perspective of growth stages, there was a gradient difference characteristic of regenerative type>maturity type>growing type>declining type. From the perspective of spatial distribution, the land green use efficiency of most resource-based cities was in the middle to low range, and showed obvious spatial agglomeration and non-equilibrium characteristics. 2) In terms of dynamic evolution, the core density curves of cities in the overall and various growth stages were fluctuating to the right, with a decrease in height and an increase in width of the main peak, a significant right tail, and a gradually emerging multi-peak shape, indicating an improvement in land green use efficiency. However, there was significant downward pressure, increasing inequality, and a certain degree of divergence and polarization. 3) From the perspective of spatial differences, the spatial differences in land green use efficiency within and between resource-based cities at different growth stages were on the rise. Regional differences and over-density were the two main sources of overall differences. 4) According to the convergence test, during the investigation period, the overall and different growth stages of resource-based cities' land green use efficiency did not show σ-convergence, indicating that regional differences were expanding. However, at the same time, there was a significant trend of absolute β-convergence and conditional β-convergence, that is, the growth rate of land green use efficiency tended to converge and gradually develop towards a steady state. ［Conclusion］ In the future, we should scientifically understand the connotation, scope, and practical value of land green use efficiency, optimize land use policies, coordinate and adapt to local conditions, in order to comprehensively improve the land green use efficiency of resource-based cities.