Coupling coordination between the ecological environment and urbanization in the middle reaches of the Yangtze River urban agglomeration

The rapid development of urban agglomerations has endangered the eco-environment. It is critical to research the coupling coordination between the eco-environment and urbanization to promote regional sustainable development. The aim of this study is to investigate the coupling coordination degree (CCD) between the eco-environment and urbanization in the MRYRUA and to identify the key factors influencing the CCD. Based on the remote sensing perspective, this study used the remote sensing ecological index (RSEI) and comprehensive nighttime light index (CNLI) to measure the eco-environment and urbanization level of the middle reaches of the Yangtze River urban agglomeration (MRYRUA). Then, based on the CCD model, the relationship between the eco-environment and urbanization was evaluated. The geographical detector was utilized to analyze the key factors. The results showed the following: (1) both the ecoenvironment and urbanization of the MRYRUA show a fluctuating upward trend, and the change rate of urbanization is greater than that of the eco-environment. (2) The overall coupling level of the MRYRUA changes from moderate unbalanced coupling to moderate balanced coupling, and the distribution of the CCD presents spatial imbalance. The coupling level of the central region is higher than that of the peripheral cities, and the coupling level of the provincial capital cities is higher than that of other cities. (3) The explanatory power of socioeconomic factors in the CCD is higher than that of natural factors in the single-factor detection; urban green space (UGS) plays the most significant role in the interaction detection. (4) RSEI has a negative correlation with the CCD, while the CNLI has a positive correlation with the CCD. The development of urbanization has played a decisive role in the CCD. The results provide a scientific foundation on which the MRYRUA can achieve sustainable urban development.