【作者】 王翠霞；

【导师】 贾仁安；

【作者基本信息】 南昌大学 ， 管理科学与工程， 2008， 博士

【摘要】 2002年后,中国的生猪养殖由大城市近郊逐渐向气候适宜的中西部农区转移,至2005年,以长江中下游为中心向南北两翼扩散的生猪生产带形成。生猪养殖的规模效益、南方农区优越的养殖条件和政府的政策导向等因素,促使生猪养殖专业户在这一带农区不断发展壮大,家庭养殖场、中小规模养殖专业户成为中国农村当前和今后较长时期内生猪养殖的主体。快速发展的农区生猪养殖,为农民带来了比种植业更多和更快的比较利益,但伴随而来的养殖废弃物污染对农业生态系统造成的危害已不容忽视。为此,政府部门投入大量资金用于农村沼气池建设,政策引导农户以沼气厌氧发酵技术处理养殖废弃物,这在一定程度上解决了生猪规模养殖粪尿污染问题。但厌氧发酵产生的沼液和沼气引起的二次污染却随之出现且日益严重。多数已经兴建了沼气池的养殖区域,尤其是偏远农区,富含有机质的沼液直接排入沟渠,以CH₄,CO₂等温室气体为主要成分的沼气直接释放入大气。常常是一户规模养猪,整个小流域被污染:农田营养过剩水稻青苗减产,沟渠、小河、水塘因富营养而成为臭水沟、死水塘,粪水、沼液雨天甚至漫入水井,污染饮用水等等,资源变成了污染源,危害严重。本文以生态系统管理的思想,以地处长江中下游水稻主产区的江西省为研究背景,选择江西省萍乡地区排上镇生猪养殖大户彭玉权的家庭生猪养殖场（泰华猪场）为具体案例,以实现养殖区域环境保护与经济发展为双重目标,将农民增收、养殖废弃物生物质资源的再生利用、以水稻为代表的种植业健康发展等问题融入生猪养殖区域环境管理,运用系统动力学（System Dynamics,简称SD）反馈动态复杂性分析理论和农业生态工程技术,针对农村普遍存在的生猪规模养殖沼液沼气二次污染的问题,研究提出并且设计应用了农村生猪规模养殖生态系统管理对策及其实施工程,最后还构建了基于农民专业合作经济组织的管理对策推广体系。本文主要研究工作和成果如下:1.将养殖场层面的环境影响评价指标和方法推广到区域层面,分别采用成分法、试验测定法、排污系数法全面而详尽地计算了江西省生猪养殖业生态足迹、单位面积耕地猪粪尿氮、磷的实际承载量、温室气体排放的全球暖化潜值四个指标,对江西省生猪养殖业的环境影响进行总体评价。结果表明:从总体而言,江西省现有的生猪养殖规模未超出其耕地的生物承载力,其农村生猪养殖污染是由于猪场废弃物因综合利用不利而在养殖区域内长期大量累积产生。2.本文综合运用图论理论和SD因果关系图理论,新提出了复杂系统关键变量顶点赋权因果关系图分析法,并应用于实践。复杂系统结构流图中,众多变量相互之间错综复杂的因果关系有时难以用数学方程式表达,系统仿真方程的建立是一个十分困难的问题,而且方程的可靠性也无法检验,成为制约系统动力学定量分析应用发展的瓶颈。基于此,本文构建了介于SD因果关系图模型和流图模型之间的中间模型——关键变量顶点赋权因果关系图（简称顶点赋权图）模型,提出定性与定量相结合的复杂系统顶点赋权因果关系图分析法。该方法从系统因果关系图关键变量的顶点值开始,由顶点因果链的关联关系、试验测试数据、顶点的实际意义等,计算出某一时点上所有顶点的值,代入因果关系图,得到该时点的顶点赋权图;之后通过比较各时点顶点值的变化,可动态分析各正反馈环与各制约负反馈环的反馈作用力度变化规律,从而寻找减弱甚至去除上限子系统各负反馈环对系统增长制约作用的杠杆解。本文将该方法应用于研究案例泰华生猪规模养殖生态系统发展主要制约问题的反馈动态复杂性分析,并据此提出了保障生猪规模养殖生态系统可持续发展的沼气、沼液综合利用的生态系统管理对策。3.构建了泰华生猪规模养殖生态系统的SD模型;新提出并运用了主导基模仿真分析法。（1）在顶点赋权图反馈分析的基础上,针对泰华生猪规模养殖生态系统管理对策,根据流率基本入树建模法,构建了由生猪数、总纯收入、生猪收入、稻谷收入、蔬菜收入、沼气收入、水稻产量、蔬菜地面积、沼液污染量与沼液综合利用量、沼气量十棵流率基本入树构成的泰华生猪规模养殖生态系统的SD流率基本入树模型,建立了系统各变量的仿真方程。（2）采用基于系统强简化流率基本入树模型的枝向量行列式反馈环算法,计算出系统结构流图的所有反馈环,分析利用这些反馈环,分别构建刻画系统三大制约问题的三个主导反馈基模。新提出并应用主导反馈基模仿真分析法,有针对性地模拟仿真相应的管理对策实施效果,检测其科学性和局限性,提出对策改进方向,为对策实施提供有效的理论指导。4.在泰华养殖区域内设计并实施了管理对策工程,环境、经济效益显著。根据泰华生猪养殖区域的地理、环境、经济等的具体实际,设计的沼液、灌溉用水分流三级沉淀净化工程,于2005年11月～2006年4月在区域内建成,投入运行后的2006、2007连续两年稻谷产量得到提高:旨在解决沼液季节性污染设计的冬闲田沼液有机蔬菜种植工程自2005年冬启动,种植面积在逐年扩大,所种植的蔬菜2006年经江西省农产品质量安全检测中心检测,达到蔬菜类绿色食品标准;旨在解决沼气污染而设计的沼气能源利用工程正在建设之中。泰华养殖区域通过管理对策的综合实施,已取得了良好的环境经济综合效益.5.通过系统分析广大中小生猪养殖户发展的上限制约,及农户专业合作经济组织对消除养殖户发展制约作用,研究构建并应用了依托农户生猪养殖专业合作经济组织的管理对策在辐射区域内的推广体系,获显著效益。本文通过管理对策的综合实施,种养结合,综合开发利用养殖废弃物资源,实现环境保护与经济发展的双重目标,推动了区域内生猪养殖健康发展、养殖废弃物资源化利用生产绿色无公害食品、农民增收、污染治理模式的良性循环。这充分揭示了:用系统动力学反馈动态复杂性反馈仿真理论和多种理论有效综合,是解决规模养殖复杂系统问题的重要途径。更多还原

【Abstract】 The pig production has been transferred from outskirts of big cities to the agricultural regions in Midwest China since 2002. The pig production belt is formed with the Middle & Lower Area of Yangzi River as its center, and spreading towards Southern and Northern regions. Due to the scale efficiency, favorable breeding conditions in South China, and the encouragement of government, the Specialized Pig Breeding Households are developing rapidly. The professional pig farming family and the medium-and small-scale specialized pig breeding household are the principal part of pig production in China rural areas now, and even a long periods aftertime.The scale pig production has brought more and faster comparative benefits to farmers than planting in agricultural regions. However, the severe pollution of cumulated breeding wastes are accompanied with the rapidly growing pig numbers, the great environmental damage which brings to the agricultural ecosystems are not allowed to be left alone again. Therefore, the government has invested largely to build anaerobic digesters for farmers, and encouraged them to use anaerobic digestion technology to dispose of the pig production excreta in recent years, which have greatly solved the pollution from excreta discharge.Unfortunately, the second pollution caused by the residual product of anaerobic digestion is flowing automatically. Investigation shows that in most farming areas, especially in many remote villages, the anaerobic digestion liquid, biogas is let directly into atmosphere due to the lack of consumers and funds. The main components of the biogas released are CH4 and CO2 that are two kinds of greenhouse gas. Additionally, abundance of organic wastes in the effluent after digestion flow freely into backward water area thus polluting water areas on the way, potable water, agricultural ecology, and living environment severely.The actuality always is one pig breeding Household pollutes the whole agricultural system in farming areas.The dissertation selects Jiangxi province, which is a main paddy production region in the Middle & Lower Area of Yangzi River, as its research spot, and Taihua pig production farm, which is a pig fanning family, owned by Pen Yuquan, located in Paishang town, Pingxiang Region, Jiangxi Province is selected as a case study. The farmers’ income, the resource utilization of farming residues, and paddy planting in the case are considered as a part of the scale pig production environmental management. With the SD feedback dynamic complexity analysis theory and approaches, a series of management strategies for eliminating second pollution in rural areas of Jiangxi Province are given and the engineering for implementing the strategies are also designed, which will ensure the aim of economy development and the environment in farming areas to be protected.The main research conclusion was summarized as follows:1. The evaluation indicators and methods to assess the environmental impact of farms are extended to the regional level environmental impact evaluation. Four environmental indicators, such as ecological footprint, loading of pig production excreta nitrogen per hectare arable land, loading of pig production excreta phosphorus per hectare arable land, and global wanning potential(GWP) expressed as kg CO2-eq/kg FPCM the component are adopted and calculated by component approach, the trail measurement and the discharge coefficient method, and the method advised by the IPCC Guidelines respectively, to assess the environmental impact of pig production in Jiangxi Province in year 2005. The assessing result shows that scale of pig production within Jiangxi province is still within its biocapacity; the pollution caused by pig production in rural areas is due to lack of piggery residues resource utilization as to leave the excreta cumulated in farming areas.2. Based on graph theory and system dynamics causal loop diagram theory, a new systemic analysis approach named vertex weighted causal loop diagram model approach to feedback dynamic complex system is presented is the dissertation. And the approach is applied to the analysis of growing limitation of Taihua scale pig production ecosystem.The stock flow diagram of complex systems always involves large numbers of variables, some relationship between them are ambiguity, some are depending on experimental dates, so it is difficult or even unable to put their relationships into mathematics equations some times, even more, the reliability of the equations are incapable to be tested. Therefore, a midst model between causal loop diagram model and stock flow diagram model of system dynamics was constructed in this dissertation, which was named the vertex weighted causal loop diagram model. The vertex weighted causal loop diagram approach is a qualitative and quantitative combined analysis approach, it starts from the value of the key variable of the system at a given time, and with this initial value, by equations of the correlated arcs or tested results of the vertexes, calculate the value of every vertex in the given time. After the value of every vertex is put into the casual diagram, the corresponding vertex weighted causal loop diagram of the studied system in the given time is generated; then by compare the dynamic variety of values of vertexes in different times, analyze the law of feedback effect of each positive and negative feedback loops of the system, to identify key leverage points and to design intervention strategies.The approach is applied to analyze the primary limits to the growth of Taihua scale pig production ecosystem, and five management strategies are put forward after that.3. A SD model of Taihua scale pig production ecosystem is constructed and three dominant archetypes for three corresponding main contradiction problems are generated respectively. The efficiency of strategies put forward after vertex weighted causal diagram analysis are simulated with the corresponding dominant archetypes.(1) In accordance with system qualitative analysis by the vertex weighted causal Loop diagram model approach, and based on the management strategies we have designed for the pig farming ecosystem, we divided the system into six subsystems; which are intensive pig farming subsystem, farmers’ total income from the system subsystem, anaerobic digester effluent subsystem, paddy planting subsystem, vegetable planting subsystem, and biogas subsystem. For each subsystem, there is a corresponding in-tree; the total in-trees construct the rate variable fundamental in-tree model of Taihua scale pig production ecosystem.The in-tree model is composed of ten rate variables fundamental in -trees. The root of a rate variable fundamental in-tree is a rate variable, the level variables or other rate variables, external variables, constants (parameters) which control the root only through auxiliary variables is called the leaves of the in-tree.(2) All of the feedback loops of Taihua scale pig production ecosystem are obtained by calculating its diagonal-1 branch-vector determinant corresponding strongly simplified rate variable fundamental in-tree model. Choosing feedback loops which have direct relations to the problem, three dominant archetypes corresponding to the three system problems are constructed respectively. Then simulate the system behavior variation caused by the implementation of management strategies with the corresponding dominant archetype, to demonstrate, amend and confirm the strategies.4. The strategies engineering is designed and implemented in Taihua pig fanning areas, the economic and ecological benefit is distinct.The anaerobic digester effluent and irrigating water diffluent engineering is constructed in Taihua pig farming area in the April of 2006, and the problem of the reduction of paddy output is settled with the engineering; the cropland vegetable planting in winter fallow engineering started from the winter of 2005, and the vegetables are through the green vegetable test, the planting areas is broadened year after year; the recycle biogas utilization engineering is on building now. Favorable economic and environmental benefits are gained by the strategies implementing in Taihua pig farming area.5. By systemic analysis of the limits to growth of the medium-and small-scale specialized pig breeding household, a management policy popularization system network based on the farmers’ professional cooperative organization is constructed.The mode of pig production healthy, breeding residues resource utilization, green vegetable planting, farmers’ income growth, contamination elimination is circulating normally with the implementation of management strategies in Taihua pig farming area, which demonstrates that it is a effectual approach to settle the problem in the scale livestock production ecosystem by combining the SD feedback & simulation theory with other theories.更多还原