Investigation on the complex relationship between urbanization and eco-efficiency in urban agglomeration of China: The case study of Chengdu-Chongqing urban agglomeration

Ecological and environmental protection is a key issue that cannot be ignored in the process of urbanization. To achieve the goal of urban sustainable development, the dynamic and complex relationship between urbanization and the ecological environment must be coordinated. A comprehensive evaluation of 16 cities within the Chengdu-Chongqing urban agglomeration from 2011 to 2020 utilized the entropy weight method, super-SBM model, and coupling coordination degree model to analyze urbanization levels, ecological efficiency, and their interplay. The findings reveal a fluctuating descent in urbanization levels with a fluctuating upward in eco-efficiency across Chengdu-Chongqing from 2011 to 2020. The coupling coordination degree, exhibiting a dynamic, bimodal distribution, reflects the intricate balance between urbanization and ecological efficiency. A kernel density model and Tobit model further elucidate the evolving nature of the coordination degree and its principal determinants. This research underscores the role of green initiatives and consumption patterns in enhancing coordination, while governmental intervention and industrial structure emerge as critical factors undermining coordination. The study provides insights for government policy formulation, offering substantial contributions to the recalibration of urban development strategies and the optimization of city planning paradigms.