Study on the Coupling Coordination between Ecological Environment and High-Quality Economic Development in Urban Agglomerations in the Middle Reaches of the Yangtze River

The ecological environment is the basis of high-quality economic development, and the coordinated development of the two is of great significance for promoting regional sustainable development. This study takes 31 cities in the middle reaches of the Yangtze River as samples, constructs an evaluation index system of the ecological environment (EE) and high-quality economic development (HQED), and uses a comprehensive evaluation method and a coupling coordination degree model to determine the development level, coupling coordination relationship, interaction coordination relationship and space–time evolution characteristics of the two. The results show that: (1) In the sample period, the overall level of EE and HQED increased simultaneously, but the two indexes of each city showed obvious heterogeneity. (2) EE and HQED have a coupling coordination relationship; the coupling degree (CD) is in a high coupling stage, and the coupling coordination degree (CCD) is in a good and moderate coordination state. (3) In the interactive coordination relationship, the CCD sequence of subsystems is coordinated development > shared development > innovative development > open development, and pressure subsystem > response subsystem > status subsystem. This study provides a new evaluation perspective for EE and HQED and puts forward suggestions for their coupling and coordinated development.