Research On Circular Economy Models Of Agricultural Watershed

At present, environmental hazards, environmental pollution and "the three rural" problems occur frequently in the agricultural watershed (i.e. AW) in the water source place in our country, which has not only affected the sustainable development of the AW itself, but also threatened the security of downstream water resources. Taken the AW in the water source place in North China (AW, for short) as the research object, this thesis can provide theory references and practice ways for AW circular economy (i.e. CE) practices to achieve the sustainable development of AW, by constructing the general models of CE for general AWs, the CE evaluation method and the specific CE models construction method for specific AW. The main research contents and conclusions of this thesis are as flows:(1) Based on AWCE system analysis, the AWCE concept, the AWCE general model concept and the AWCE specific model concept are defined, and then the AWCE related theories are discussed. Based on all this, an AWCE theory frame with remarkable systematic and layered characteristics is proposed, which provides a research basis for AWCE theory and its models study.(2) Based on the AWCE theory frame, AWCE general models with three levels compound are constructed, which include the general models of tradition industrial enterprise CE, agricultural products processing enterprise CE and farmer courtyard circular agriculture at microscopic level, the general model of sub-watershed CE at intermediate perspective level, and the general model of AWCE at regional level. These general models provide a pattern frame to some specific AW and theory references for general AWCE practices, which are worth popularization.(3) From the view of serving specific AWCE models construction, a quantitative analysis and qualitative analysis unified AWCE evaluation model is proposed, which synthetically utilizes following five evaluation methods: first, the general water resource evaluation model based on the SWAT hydrological model; second, the general AWCE development level evaluation method and land use evaluation method based on foot print analysis; third, the evaluation method of AWCE development limiting factors by Delphi and AHP methods; forth, the dominant industries and products evaluation method mainly based on the relative comparative advantage index assessment; last, the SWOT qualitative analysis method. Furthermore, in order to explain the method of application in details, this AWCE evaluation model is applied to Biliu upriver watershed. The application results show that this evaluation model can provide more reliable and extensive basis for specific AWCE models construction.(4) Taken the optimization design of AWCE specific models as the core, a construction method of AWCE specific models is proposed. Furthermore, in order to explain the method of application in details, this method is applied to Biliu upriver watershed. As the results, the farmer courtyard "Seven-in-one" circular agriculture model of Biliu upriver watershed, the Sub-watershed CE model of Biliu upriver watershed, and the CE model of Biliu upriver watershed are constructed. The application results show that this construction method can be used to construct CE models for some specific AW.