Study on the coupling coordination relationship between economic development and ecological environment protection in Gansu Province

To evaluate the degree of coupling and coordination between economic development and ecological environment protection, the coupling coordination relationship between economic and environmental systems was studied by using the comprehensive development evaluation model and the coupling coordination degree model. Taking Gansu Province as an example, the coupling coordination between economy and environment at the provincial level and 14 cities (prefectures) under its jurisdiction from 2011 to 2019 were analyzed in terms of time and space. The results showed that: 1) The comprehensive development level of Gansu Province increased year by year, and the coupling coordination degree of economy and environment increased from 0.005 5 to 0.911 0. The coupling coordination level of Gansu Province was generally on the rise, and achieved good coupling coordination in 2017 with the synchronization economic development and ecological environment protection. 2) The comprehensive development level of economy and environment in 14 cities (prefectures) showed an upward trend, and some cities (prefectures) showed fluctuations in 2016 and 2018. The comprehensive development level of Jiuquan and Lanzhou was higher, while that of Gannan and Dingxi was lower. 3) The coupling coordination degree of economy and environment in 14 cities (prefectures) all broke away from the imbalance recession and entered the coupling coordination stage in 2016. In space, it was the best in the central region, followed by the north and slightly worse in the south.