水保所知识产出(1956---)知识库

针对黄土高原丘陵区经济系统与生态系统相悖态势及如何实现资源的合理配置等问题，选择典型代表区——陕西省吴起县作为研究对象，研究其农业生态经济系统20余年的演变过程，探讨农业生态经济系统的演变阶段、特征及其驱动机制，分析了农业生态经济系统的耦合关系，应用耦合度模型和耦合过程模型对吴起县进行了实证分析，并预测了系统的耦合态势。在此基础上，提出农业生态经济系统健康、持续发展的策略与建议。主要结论如下：
（1）应用聚类分析方法，并参照已有的研究结果，将吴起县1990-2007年农业生态经济系统演变过程划分为：1990-2002年为生态经济系统演变的第Ⅱ阶段，其中1990-1996年处于该阶段初期，1997-2002为该阶段中后期；2003-2007步入第Ⅲ阶段。
（2）运用主成分分析的方法，对吴起县农业生态经济系统演变的驱动因素进行了分析，结果表明：第一主成分因子载荷的绝对值排序为总人口（X1）＞人均纯收入（X18）＞人口密度（X2）＞工副业收入（X17）＞农业产投比（X13），即主要是人为经济发展驱动；第二主成分因子载荷绝对值的排序为人均粮食产量（X11）＞种植业收入（X14），反映的是人口压力驱动因子；第三主成分里年平均降雨量（X9）占的比重最大且明显高于前两个主成分里的因子载荷，说明第三主成分主要反映年平均降雨量的影响，即自然生态环境驱动因子。不同类型的土地利用面积，在各主成分中，大多处于中间水平，在某一程度上影响作用较大，反映了政策-产业结构调整的驱动。通过比较，得出：人为经济发展因素是农业生态经济系统演变的主要驱动力，人口压力驱动因子和政策-产业结构调整驱动因子次之，而自然生态环境是影响吴起县农业生态经济系统耦合过程的基础。
（3）应用结构方程模型（SEM）方法，分析了吴起县农业生态经济系统耦合关系，结果表明：具有相关关系的农业资源和产业态势对系统耦合有一定影响，其影响系数分别为0.14和1.00；农业资源与产业态势之间的相关系数为-0.11，说明吴起县的产业发展并非建立在对农业资源有效利用基础之上，农业资源对经济效益的变化没有直接作用；产业的发展主要建立在对农业资源之外的能量和物质的开发利用上，导致产业态势对经济效益的直接路径系数为-2.95，总的路径系数仅为0.23。目前在农业生态经济系统良性耦合机制的建立与形成过程中潜伏了较大危机。
（4）通过“耦合度模型”的构建与分析，发现近20年来吴起县农业生态经济系统演变经历了“不协调耦合阶段-协调耦合阶段-不协调耦合阶段”，表明生态经济系统潜伏了较大的危机。这一结果与结构方程模型分析结果相一致。
（5）运用“耦合过程模型”对吴起县实证分析的结果表明：按照农业生态经济系统现状演变轨迹，农业生态系统自我调节的临界点为)(375.1)(telten×=；如果停止“退耕”而出现复垦，生态系统自我调节的临界点变为)(968.0)(telten=，单位生态系统功能减弱。在阈值范围内，通过建立良性的系统耦合，能够实现生态经济系统的稳定持续发展。
（6）针对目前吴起县农业生态经济系统发展中凸现的现实问题，提出吴起县农业生态经济系统良性发展策略：优化系统内部产业结构，加强资源产业耦合，培育后续产业；扶持以林草和石油开发为主的产业链的形成；建立长效机制, 继续推进退耕还林工程；加强农民文化素质的提高和促进劳动力转移。

Aimed to resolve the problems of contradicting situation between economic system and ecological system and rational distribution of resource in Loess Hilly-gully Region, Wuqi County in Shaanxi Province was chose as the research area to study its evolution process of agricultural eco-economic system during last more than 20 years. The different evolution stages, characteristics and driving factors of agricultural eco-economic system were analyzed, coupling relationship of agricultural eco-economic system was discussed, and applied the coupling degree and coupling process model to analyze agricultural eco-economic system and predict its coupling trend in Wuqi County. Based on the above analysis, strategies and suggestions to promote normal and sustainable development of agricultural eco-economic system were put forward. The main results as follows:
（1）Applied the method of cluster analysis and referred to existing study results to divide evolution stages of agricultural eco-economic system in Wuqi County from 1990 to 2007. The results indicated that the agricultural eco-economic system from 1990 to 2002 was at stage 2, the system from 1990 to 1996 was at initial phase of stage 2, and the system from 1997 to 2002 was at middle and later phase of stage 2. The agricultural eco-economic system began to enter into stage 3 from 2003 to 2007.
（2）The driving factors of agricultural eco-economic system were analyzed with the method of principal component analysis in Wuqi County. The results indicated that the absolute values of the first principal component factor load were ranked as follows, the whole population(X1)>the net income per person(X18)>the population density(X2)>the income of the second and third industry(X17)>the agricultural output/input ratio(X13), and these factors were called as economic development driving factors. The absolute values of the second principal component factor load were ranked as follows,, the grain yield per person(X11)>the income of planting(X14), and they represented the population pressure driving factors; in the third principal component, the average annual rainfall factor took up the biggest percentage, and was obviously higher than the factor loads in the first and second principal component. The third principal component represented the effect of the average annual rainfall, which was called natural ecological driving  factors. The different areas of land use in various principal component were at the mid-level and their effects were relatively strong, which were called policy-industry structural adjustable driving factors. Through comparisons, man-made economic development factors were main driving force to promote evolvement of agricultural eco-economic system, and followed by the population pressure driving factors and policy-industry structural adjust driving factors, while eco-environment was basics of coupling process of agricultural eco-economic system in Wuqi County.
（3）The coupling relationship of agricultural eco-economic system in Wuqi County was analyzed by applying the method of SEM. The results showed that agricultural resource and industry situation had effect on the system coupling, and their influence coefficient were 0.14 and 1.00 respectively; the correlation coefficient between agricultural resource and industry situation was -0.11, which indicated that industry development was not based on effective utilization of agricultural resource, and agricultural resource had not directly influence economic effect. The direct path coefficient of industry condition on economic effect was -2.95, while the whole path coefficient was only 0.23, which showed that industry development was mainly based on substance and energy outside the agricultural resource. In the present time, some crisis was hidden in the process of establishing benign coupling relationship of agricultural eco-economic system.
（4）The evolvement process of agricultural eco-economic system was analyzed by the model of coupling degree. The results indicated that Wuqi County agricultural eco-economic system during the last 20 years passed through the process of “incoordination coupling stage-coordination coupling stage-incoordination coupling stage”, which showed some crisis was hidden in agricultural eco-economic system. The result is consistent with the one analyzed by the the structural equation model.
（5）Applied coupling process model analyzed coupling process of agricultural eco-economic system in Wuqi County. The results showed that the self-adjust boundary point of agricultural eco-economic system was , if agricultural eco-economic system evolve at current system evolution speed; the self-adjust boundary point of agricultural eco-economic system was and function of eco-system would be weakened, if the Grain for Green Project is discontinued. The normal and sustailable development was realized by establishing benign system coupling under the restriction of threshold. )(375.1)(telten×=)(tel968.0)(ten=
（6）Aimed to resolve the problems in the process of agricultural eco-economic system development, the benign development strategies for coupling of agricultural eco-economic system development were put forward in Wuqi County; optimized industrial structure of ecological economic system, strengthened coupling development between resource and industry, and cultivated follow-up industry; The industries related forest, grass, exploiting petroleum were supported; Long-effective mechanism was established to propel Grain for Green Project; the cultural quality of farmers was improved, and labor force transfer was promoted.