An evaluation framework for industrial ecology based on the symbiosis theory-Taking the π-shaped Curve Area in the Yellow River of China as an example

This paper defined regional industrial ecology (IE) to include four connotations: sustainable social-economic-ecological development, the high-quality transformation of the industrial system (IS) and the ecological system (ES), and harmonious symbiosis between IS and ES. Regarding the composition of the symbiotic system, this paper proposed that the IE evaluation be carried out from three aspects: the sustainability of the symbiotic environment, the high-quality development of the symbiont, and the symbiotic pattern between the symbiotic units. Then, the maturity index determined by the symbiont and symbiotic mode and the orderliness index determined by the symbiont and symbiotic environment were measured to determine the IE level from the perspectives of the system's function and structure. Besides, this paper adopted Geodetector and Oprobit model to identify the influencing factors of IE. Taking the π-shaped Curve Area of the Yellow River as the study area, this paper found that the IE systems' structural orderliness of capital cities and resource-based cities was low, while the orderliness level of non-resource-based cities was high. The IE systems' functional maturity level in the northwest Area was better than that of the southeast. The IE level was high in Inner Mongolia while low in Shanxi and Ningxia. Scientific innovation, economic development, openness degree, ecological pressure, industrial structure, urbanization level, and government influence have different influences on the IE systems' orderliness and maturity levels. The findings of this paper provided a basis for realizing IE and promoting the high-quality transformation of the whole basin.