Integrated evaluation of resource and environmental carrying capacity during the transformation of resource-exhausted cities based on Euclidean distance and a Gray-TOPSIS model: A case study of Jiaozuo City, China

The development process of resource-based cities has obvious stage characteristics, and its resource and environmental carrying capacity is an important dynamic index to measure sustainable development and a powerful tool for the government decision-making, especially for resource-exhausted cities. Therefore, it is particularly necessary to accurately evaluate the carrying capacity of coal cities and correctly diagnose the obstacle factors. As one of the first resource-exhausted cities in China, Jiaozuo City has undergone different stages of evolution in its resource and environmental carrying capacity in the process of successful transformation. To this end, we constructed a Grey Relational Analysis model of Euclidean Distance based on TOPSIS (ED-GRA-TOPSIS) to evaluate the carrying capacity of the three subsystems of Resources, Environment and Socio-economic (RES) in Jiaozuo City from 2004 to 2019, and a diagnosis model of obstacle degree to calculate and analyze the main controlling factors affecting its sustainable development. The results show that: (1) The comprehensive resource and environmental carrying capacity of Jiaozuo City has experienced three stages of slow improvement (2004-2008), steady development (2009-2012) and rapid promotion (2013-2019). (2) In the early years, relying on resource endowment, the development level of the resource subsystem was obviously higher than that of the other two subsystems, followed by a "W"-shaped fluctuation; The carrying capacity of the environmental and socio-economic subsystems presents an upward trend. (3) Scientific and technological innovation, ecological and environmental protection, public infrastructure investment and green development are the main restrictive factors of Jiaozuo's economic and social development, which weaken the temporary carrying capacity of its urban development, but in the long run, they are the primary driving force of sustainable development. Specific countermeasures and suggestions were proposed, including restricting the exploitation of resources and strictly controlling the emission of pollution, increasing the construction of urban public infrastructure and improving the level of public services, rationally planning the development direction of the industry and avoiding dependence on coal to another dependent development model. By establishing the ED-GRA-TOPSIS model, the reliability and rationality of the evaluation results are verified, which can provide reference for the formulation of development strategies of resource-based cities.