Application-oriented Assessment And Practice Of Environmental Carrying Capacity

Environmental carrying capacity(ECC)is an important index in evaluating regional sustainable development.In recent years,numerous regions in China are suffered from environmental pollution and resource exhaustion,along with the rapid development of economy,which severely restricts the sustainable development of our national economy.Therefore,evaluating the ECC in a scientific way,to keep the human activities within compass,has important significance for developing geographical space and sustainable development.Currently,the theoretical and methodological study of ECC have achieved lots of research results.However,the evaluation method system of ECC hasn't been consummate yet,which limits operational application of ECC in the regional government management to a certain extent.ECC is a multi-disciplinary topic.Therefore,this thesis reviews the history,the concept and the theoretical basis of ECC.Based on summarizing the developments of the study on ECC,The thesis considers that the evaluation method of ECC can be categorized into four types,which includes the index system method,system modeling method,environmental capacity method and supply-demand balancing method.Through the review,it is found that the evaluation of ECC has not formed a unified technological path or an operational management platform,and took little account of the feedback mechanism of elements and subsystems,as well as the influence between regions.Furthermore,the demands on the evaluation of ECC for operation application are analyzed,which mainly includes the comprehensive evaluation model of ECC,the evaluation on division zones and the monitoring and warning mechanisms for ECC.A methodology framework on ECC for operation application is built,from the point of view for regional government management.The main ideas are as follows: Based on the major function oriented zoning and the concept model of regional composite system,the thesis builds frameworks of evaluation index system for different zones,which consist of basic elements and characteristic elements.Besides,this thesis proposes an evaluation method for operation application,which evaluates the ECC in two aspects with vector norm method and relative surplus ratio,and determines weights by analytic hierarchy process and entropy method.The evaluation model based on urban area is applied into Bao'an District in Shenzhen City,which evaluates the ECC of Bao'an District as well as the coupling coordination degree from 2011 to 2016,and predict the variation trend of the ECC from 2017 to 2022.The main achieved results of are listed as following:(1)Although the overall trend of ECC is increasing from 2011 to 2016,the ECC of Bao'an District is at a low level over these years,which is influenced strongly by environment subsystem and resource subsystem.In addition,the key elements that constrained the ECC of Bao'an District are water environment,water resource,utilization efficiency of water resource and emissions-intensity of water pollutants.(2)Based on the coupling coordination degree model,the overall trend of coupling degree and coupling coordinative degree between the carrier and the carrying target of ECC in Bao'an District are analyzed,which both keep in sustainable growth from 2011 to 2016.In addition,the carrier and the carrying target of ECC in Bao'an District are in a state of high coupling,but the development of Bao'an District is in a state of seriously unbalanced from 2011 to 2016.(3)The ECC of Bao'an District is in a state of overload from 2011 to 2016,which is in a state of serious overload between 2011 and 2012,and turns into moderate overload between 2013 and 2016.(4)Based on the linear regression model,the ECC of Bao'an District from 2017 to 2022 is predicted.The results shows that the ECC of Bao'an District grows rapidly,but still be lightly overload between 2017 and 2021.However,the ECC of Bao'an District will become surplus in 2022.According to the results of evaluation of the ECC in Bao'an District,the thesis proposes pertinent suggestions to improve the ECC of Bao'an District,from the aspects of water pollution,water resource utilization and emissions-intensity of water pollutants.Through the study of the ECC evaluation in Bao'an District,the scientificalness and the feasibility of the ECC evaluation method for operation application are basically proved,which has reference value for the operation application of ECC.However,the case study also shows that there are still imperfections of the evaluation method in the feedback mechanism of elements,the selection of indexs and the building of the evaluation model,which should be improved in future research.