Exploring the relationship between urbanization and the eco-environment—A case study of Beijing–Tianjin–Hebei region

Chinaʹs high-speed economic growth has been characterized by rapid urbanization and a series of environmental issues. This study investigates the urbanization and eco-environment system from the perspective of interactive coercing theory and proposes a new comprehensive index system for the assessment of urbanization and the eco-environment. This is done using interactive coercing model (ICM) followed by a dynamic coupling coordination degree model (DCCDM) to estimate the relationship between urbanization and the eco-environment. This study focuses on the interactive coercing relationship, coupling coordination degree and coordinated patterns in the BTH (Beijing–Tianjin–Hebei) region, China, with panel data collected from 1980 to 2011. The main conclusions are as follows: (1) demographic urbanization and eco-environmental endowment make the greatest contribution to the compound system, indicating that they are the critical factors to consider when analyzing the interactive coercing relationship between urbanization and the eco-environment; (2) we find the double-exponential curve of urbanization and the eco-environment is in the form of an inverted-U curve, and thus the Kuznets hypothesis is confirmed by the empirical analysis; and (3) the dynamic of coordination of the selected cities shows an S-shaped curve and the corresponding state of the degrees evolves into the rudimentary symbiosis phase from the harmonious development phase during rapid urbanization, and it is revealed that the coordinated patterns of most sample cities are sensitive to the eco-environment, which indicates that the urban environment is subject to great pressure. The comprehensive indexes and the interactive coupling models may help the governments better understand the complex coupling relationship, and develop sustainable urbanization development strategies that better balance urbanization and eco-environmental protection.