Coupling coordination analysis of urbanization and energy eco-efficiency: a case study on the Yangtze River Delta Urban Agglomeration.

The coordination of urbanization with the ecological environment has become a significant sustainable urban development problem given the current acceleration in China's urbanization. The existing research lacks in-depth discussion on the coordination relationship between urbanization and energy eco-environment from the perspective of urban agglomeration. This paper takes the Yangtze River Delta Urban Agglomeration as its research area. The combination of CRITIC and entropy weight methods is used to measure the comprehensive urbanization level (CUL) from the four dimensions of population, economy, land, and society, and the SBM-Undesirable model is used to measure the energy eco-efficiency (EE). The spatiotemporal pattern and dynamic evolution law of the coupling coordination degree (CCD) between CUL and EE are analyzed using the coupling coordination model and the spatial Markov chain. The research results reveal that (1) from the comprehensive development level standpoint, both CUL and EE are on the rise from 2010 to 2021; however, a problem of unbalanced development is observed. (2) The overall CCD displays an upward trend and evinces significant spatial differentiation characteristics from the coordinated development level viewpoint. (3) The CCD transition state is not isolated to certain geographic spaces: adjacent cities will impact changes in the coupling coordination types of an urban center. Therefore, we propose strategies to improve the CCD between CUL and EE to offer theoretical and policy inferences for the formulation of sustainable urban development strategies.