Research On Sustainable Development Of Resource-Type Cities Based On Emergy Theory

As an important strategic guarantee base for energy and resources in China,the sustainable development of resource-type cities is one of the hot topics in current social research.However,in its development,a single development model often leads to its ecosystem being more fragile than ordinary cities,with obvious characteristics of complexity,fragility,ecological sensitivity.and heterogeneity.At present,its predatory development has brought many problems of resource depletion and urban development,such as unreasonable economic structure,high resource dependence,large energy consumption and serious deterioration of ecological environment.In this context,choosing a path with reasonable economic structure,low energy consumption,and ecological friendliness is a huge challenge for the sustainable development of resource-type cities in China.At the same time,with the continuous pursuit of green and low carbon cycle development model in China,it should have real significance and practical significance to further explore the sustainable development of resource-type cities.This paper selects Jining,a typical coal-based city in Shandong Province,as the research object.According to the research idea of "retrospective analysis—prediction and evaluation—capacity improvement",the emergy theory is introduced,and methods such as system dynamics(SD)and TOPSIS are used.The most suitable path for sustainable development for resourcetype cities is selected through quantitative analysis.Firstly,construct a sustainable development evaluation index system based on emergy indexes,and conduct a retrospective analysis of the sustainable development of Jining in the past two decades.The research results show that compared to 2001-2010,the sustainable development of Jining during 2011-2020 has fluctuated but tends to be stable,indicating that Jining is gradually transforming from a resource-driven economic development model to a sustainable model of coordinating resources,economy,and environment.Secondly,based on the basic data of Jining in the past twenty years,an SD model with emergy as the evaluation indexes is constructed.Identify the key variables that affect the sustainable development of Jining through the coupling of regression analysis and SD sensitivity analysis.Finally,key variables are used as regulatory factors for scenario design,designed according to three different scenarios:low.medium,and high,and scenario combinations are conducted to construct several scenarios.Use the SD model to predict and classify the sustainable development level of scenario combinations with different preferences in future planning years,select a suitable scenario from each preference,and use TOPSIS method to quantify and analyze them in combination with difficulty.The results are as follows:the appropriate scenario H-M-H-M under the resource preference has a score of 0.2502,which indicates insufficient environmental protection efforts and excessive development of nonrenewable resources,making it impossible to achieve the most sustainable state;The appropriate scenario H-L-H-H under economic preference has a score of 0.5951.This method attributes the driving force of economic development to renewable resources,which is too idealistic and difficult to implement;The appropriate scenario M-L-H-H under environmental preference has a score of 0.5965.This method reduces the investment of non-renewable resources while doing a good job of environmental protection,pays attention to the coordinated development of resources,economy and environment,demonstrating the best level of sustainable development,making it the most suitable development model.At the same time,If Jining predicts the sustainable development status in 2030 according to the most suitable sustainable development model,the results indicate that the sustainable development level of Jining will be further improved.Based on this,according to the characteristics of the best scenario itself,corresponding suggestions are provided for the sustainable development of Jining:it is suggested that the appropriate development range of the increase rate of social fixed assets investment in Jining during the "14th Five Year Plan" is 4.4%～5.2%;The suitable development range of raw coal emergy is 5.39E+22～5.47E+22 sej;The suitable development range of the increase rate of grain emergy is 1.4%～1.8%;The suitable development range of solid waste emergy is 1.16E+22～1.76E+22 sej.In the future,Jining should focus more on improving environmental quality and optimizing the adjustment of resource structure.First,it should establish a complete environmental protection and governance system and increase investment in green infrastructure;Second,it should further increase the proportion of renewable resources,slow down the development speed of non-renewable resources,do a good job in transforming traditional industries into new kinetic energy industries,and accelerate the cycle of nonrenewable resources from raw material utilization to waste reuse.