Evolution process analysis of urban metabolic patterns and sustainability assessment in western China, a case study of Xining city

Rapid urbanization has brought about a series of resource and environmental problems in China, especially in the western areas with fragile ecological environment conditions and weak economic basis. Therefore, the sustainable development of the western regions is of great importance, and how to choose a more reasonable development path has become an urgent problem. From the theory of systems ecology, this study analyzed the metabolic structure, efficiency and evolution of development mode of a typical western city-Xining based on the ecological emergy analysis. In addition, the paper puts forward effective policy suggestions to promote sustainable development in accordance with local characteristics. The study found that the sustainability level of Xining had been declining during the study period overall from 330.85 to 15.46, but the its decline rate had been decreasing, and finally the sustainability level remained stable in the last several years. It is closely related to the ecological civilization construction and green development strategy adopted by Xining city. With the development of economy, the metabolic efficiency of Xining has been improved and the metabolic structure has gradually become more reasonable due to the decline in emergy use per GDP and escalation in emergy exchange rate. The development of Xining can provide a role model and reference for the western regions, and the study could provide scientific basis and theoretical guidance for the sustainable development of western cities.