Coordinated relationship and influencing factors of ecological environment and socio-economic coupling of urban agglomeration around Hangzhou Bay in China

The coupling and coordination relationship between social economy and ecological environment is a key concern and hot spot for sustainable development. Taking the Hangzhou Bay city cluster in China as the research object, this paper constructed a comprehensive evaluation index system for the coupling and coordination degree of social economy and ecological environment. With the help of ArcGIS software, the coupling and coordination degree model, and the Pearson correlation coefficient, the paper analyzed the ecological environment, social and economic development index, and coupling and coordination degree and their influencing factors of the Hangzhou Bay urban agglomeration from 2000 to 2019. The results showed that:（1） from 2000 to 2019, the socio-economic index of the Hangzhou Bay urban agglomeration presented a stable upward trend, while the ecological environment index showed an up-and-down fluctuation followed by an upward trend year by year;（2） During 2000-2014, the development rate of the socio-economic index was greater than the growth rate of the ecological environment index. The development rate of the ecological environment was greater than the development rate of the social economy from 2015 to 2019;（3） From 2000 to 2019, the coupling coordination between the socio-economic and ecological environment of the Hangzhou Bay Rim City Cluster overtook good coordination to perfect coordination. Among which, the coupling coordination of Shanghai and Hangzhou in 2000 lagged behind the other cities, and Suzhou was the only city in the Hangzhou Bay urban agglomeration that did not reach perfect coordination in 2019;（4） Population density, air quality, industrial wastewater emissions, and industrial solid waste were the main hindering factors for the improvement of the coupling coordination of the Hangzhou Bay urban agglomeration.