Examination of a coupling coordination relationship between urbanization and the eco-environment: a case study in Qingdao, China.

A better understanding of the relationship between urbanization and the eco-environment is necessary to guide sustainable urban development and formulate environmental policies. In this study, the city of Qingdao was taken as an example. We evaluated the quantitative evolution of the relationship between urbanization and the eco-environment development from 2000 to 2018 by establishing the comprehensive index system and applying it to the coupling coordination model. Results showed the following: (1) The economic urbanization and eco-environment states offer the greatest contribution to the urbanization and eco-environment systems, respectively. (2) The coupling coordination relationship between urbanization and eco-environment conforms to an S-shaped curve, and the two systems have gradually moved from a "seriously uncoordinated and urbanization lag" stage at the beginning into a "good coordination and eco-environment lag" stage by the end of the research period. (3) Finally, the economic urbanization and response subsystems are essential determinants in the coupling relationship between urbanization and eco-environment. The research results can help the government better understand the complex coupling relationship and then formulate sustainable urbanization development strategies to better balance urbanization and eco-environmental protection.