【作者】 赵建民；

【导师】 李靖；

【作者基本信息】 西北农林科技大学 ， 水土保持与荒漠化防治， 2010， 博士

【摘要】 作为生态环境建设的重要内容,水土保持是一项实践性很强的农林水事活动。为了评价水土保持的实施效果、明确水土保持的目的与意义、对不同的水土保持方案进行比较与优选,有必要进行水土保持效益评价研究。水土保持涉及到生态环境与社会经济的方方面面,单一指标不可能评价其综合效益,因此,人们常用两类方法进行评价:即基于系统工程理论的水土保持综合效益评价与基于生态系统服务理论的水土保持综合效益评价。本文重点研究了基于生态系统服务理论的水土保持综合效益评价理论与方法,通过优选评价指标,构建了评价指标体系,建立了评价模型,确定了评价模型中的基本参数;以延河流域中尺度水土保持生态环境建设研究区为实证研究对象,评价了水土保持对研究区域内外生态系统服务功能的影响及驱动因子,分析了影响生态系统服务功能进一步改善的主要问题,提出了解决这些问题的策略和方法。研究表明,生态系统服务理论对科学地确定水土保持综合效益评价因子、完善水土保持评价指标体系具有一定的指导意义。基于系统工程理论建立水土保持综合效益评价指标体系是一种多目标评价方法,需要从水土保持对方方面面的影响中选择出评价指标并归一化,确定各评价指标的评分值和权重,最后通过一定的数学方法,将水土保持对各方面的影响转化为一个最终的评价值,但该值只是一个相对值,并不具有真实的生态学或经济学、社会学意义,在评价指标选取、归一化和权重因子确定等方面常常因人而异,差距甚大,不同的评价指标体系之间不能直接比较。本文对20世纪90年代以来国内学者提出的若干水土保持综合效益评价指标体系进行了统计分析,根据出现的频率在67个评价指中选定了13个常用的评价指标。生态系统服务功能评价理论是基于生态系统服务理论的水土保持综合效益评价的理论基础。生态系统服务功能包括价值与使用价值,可用生态系统服务价值、生态足迹、能值、虚拟水等指标衡量。但是,目前生态系统服务功能评价理论与方法尚不成熟。本文在前人理论研究和实践的基础上,对生态系统服务功能评价的理论与方法进行了新的探索:在生态系统服务价值评价中区分了存量价值与增量价值;在生态足迹核算中初步提出并解决了中间产品、产量因子计算等方面存在的问题;将能值划分为生态系统服务能值与生态系统维持能值,并根据二者间的关系将生态-社会复合系统划分为四种基本类型;在进行虚拟水计算时区分了“蓝虚拟水”与“绿虚拟水”,初步构建了人类活动对水资源利用效率影响的评价体系。根据生态系统服务功能评价理论与模型,本文采用直接或间接的方法,建立了水土保持的水圈、土圈、生物圈、大气圈效应对研究区域内外生态系统服务功能影响的评价模型,并将水土保持的综合效益用四个指标表示,即生态系统服务价值、生态承载力、能值与虚拟水量。通过理论推导与实验分析相结合的办法,初步确定了评价模型中的基本参数。实证研究表明:从1997年到2004年,研究区人均生态系统服务价值由1966元增加到2364元,其中人均生态系统内部服务价值(农业增加值)由1300元增加到1487元,人均生态系统外部服务价值由666元增加到877元;研究区人均生态承载力由2.03hm2增加到2.28hm2,其中内部生态承载力由人均1.20hm2增加到1.24hm2,外部生态承载力由人均0.83hm2增加到1.04hm2;人均生态系统服务能值输由3024.6Gsej增加到3745.1Gsej,其中内部能值由586.2Gsej增加到697.8Gsej,外部能值由2438.4Gsej增加到3047.3Gsej;研究区水土保持提高改善黄河流域水资源利用率的效益由1997年的2435m3/人增加到2004年的2884m3/人,其中内部效益由898m3/人增加到1084m3/人,外部效益由1537m3/人增加到1800m3/人。研究区水土保持生态系统服务的内部价值高于外部价值,但外部使用价值高于内部使用价值。且生态系统外部服务的增速较快。上述4种评价结果显示:林地的生态系统边际服务功能最高,其次是梯田与果园,草地最低。农田与果园的生态系统服务主要表现为内部服务与经济效益,林地与草地的生态系统主要表现为外部服务与生态、社会效益。基于系统理论的水土保持综合效益评价指标体系显示,研究区水土流失综合治理目标的实现程度由65.95%增加到72.90%,研究区社会效益方面目标实现程度较高,生态效益方面提高较快,尤其是治理程度和植被覆盖率等方面成效尤为显著。目前,人均基本农田、人均粮食等指标已经达标,治理程度与林草覆盖度等指标也完成了目标值的70%-90%,但在侵蚀模数、人均收入、劳动生产率、土地利用率等指标方面目标实现程度仍较低,是今后需要进一步加强工作之重点。基于生态系统服务与基于系统理论的水土保持综合效益评价,其评价结果具有一致性。一般而言,基于生态系统服务的水土保持综合效益评价更具有科学性与系统性。基于系统理论的水土保持综合效益评价的主要特点是其判别功能,可以指出水土保持工作中存在的主要问题。本文在理论上探讨了基于生态系统服务理论的水土保持综合效益评价理论与方法,扩大了生态系统服务功能评价理论的应用范围;在实践上提出并建立了基于生态系统服务理论的水土保持综合效益评价方法与模型,确定了模型中的基本参数,进行了实证研究,提出了影响生态系统服务功能提高的主要问题和解决方法。论文初步完成了预定目标,即在总结前人研究成果的基础上,尝试性地提出了基于生态系统服务理论的水土保持综合效益评价模型与指标体系。更多还原

【Abstract】 As an important part of the ecological environment construction, soil and water conservation is a very practical activity in agricultural, forestry and water affairs. It is necessary to research the benefit evaluation of soil and water conservation for evaluating the implementation effect, conforming the purpose and significance or comparing and choosing the implementation plan of soil and water conservation. Due to various effects in ecological environment and socio-economic aspects, a single indicator cannot evaluate the overall impacts of soil and water conservation. Therefore, two methods often used to evaluate the comprehensive benefit of soil and water conservation. One is based on the theory of system engineering, the other is according to the theory of ecosystem services. The theory and methods of comprehensive benefit evaluation for soil and water conservation according to the theory of ecosystem services were mainly studied in this article. The evaluation index system was established by optimizing indexes for evaluation. The evaluation model was established, and basic parameters in the model were determined. Taking middle scale research and demonstration region of soil and water conservation and ecological environment construction in Yanhe River basin as empirical research object, the impacts of soil and water conservation on the function of ecosystem services in and outside the research region and the driving forces of the ecosystem services changing were evaluated. At the same time, the main problem in the further improvement of ecosystem services, and the strategy and methods of solving these issues were analyzed. It was shown in the study that the theory of ecosystem services has a certain significance to scientifically determine factors of comprehensive benefits, improve the evaluation index system for soil and water conservation.The index system of comprehensive benefit evaluation for soil and water conservation based on the theory of system engineering is a method of multi-objective evaluation, which needs to select and normalize the evaluation indexes from all impacts of soil and water conservation, determine the score value and weight of each index, and finally transform the impacts of soil and water conservation on various aspects to a final evaluation value by mathematical methods. But the evaluation value is only a relative value, does not have a real ecological or economic, sociological significance. There are some differences in the selection and normalization of evaluation indexes, the decision of weighting factors and so on in different index systems. So the evaluation results between different index systems cannot be directly compared. In this article, a number of evaluation index systems for soil and conservation proposed by national scholars in 1990s were statistical analyzed. According to the frequency of 67 evaluation indexes, 13 indexes were selected as common indicators.The comprehensive benefit evaluation for soil and water conservation according to the theory of ecosystem services is based on the theory of ecosystem services. The function of ecosystem services include the value and the use value, which could be assessed by ecosystem services valuation, ecological footprint, emergy and virtual water and other indicators to measure them. However, the current theory and methods of ecosystem services assessment were not perfect. In this paper, some new works in ecosystem services assessment have been done based on the former theories and practices. The stock and incremental value were distinct in ecosystem services valuation. The question of intermediate products and yield factor in the ecological footprint calculation were initially proposed and solved. Emergy was divided into the emergy for ecosystem services and the emergy for ecosystem to maintain energy and the energy value. Based on the relationship between emergy for ecosystem services and for ecosystem sustaining, ecological– social complex system was divided into four basic types. The "blue virtual water" and "green virtual water" in the calculation of virtual water were distinct. The initial evaluation system of the human activities on water use efficiency was established.According to the theory and models of ecosystem services assessment, the evaluation models of impacts on water, soil, biosphere, and atmosphere by soil and water conservation on the ecosystem services in and outside the research region were established by direct or indirect methods. According to these models, the comprehensive benefits for soil and water conservation were assessed by 4 indicators, which are ecosystem services valuation, ecological capacity, emergy and the virtual water. And the basic parameters in these models were initially determined through theoretical and experimental analysis.It could be known in this research: from 1997 to 2004, ecological services valuation per capita in the research region increased from 1966 yuan to 2384 yuan, in which internal ecological services valuation(agricultural added value)increased from 1300 yuan to 1487 yuan, external ecological services valuation(agricultural added value)increased from 666 yuan to 877 yuan; ecological capacity per capita increased from 2.03 hm2 to 2.28 hm2, in which internal capacity increased from 1.20 hm2 to 1.24 hm2, external capacity increased from 0.83 hm2 to 1.04 hm2; emergy for net ecological services per capita increased from 3024.6 Gsej to 3745.1 Gsej, in which internal emergy increased from 586.2 Gsej to 697.8 Gsej, external emergy increased from 2438.4 Gsej to 3047.3 Gsej; the available water resource increased by soil and water conservation per capita increased from 2435 m3 to 2884 m3, in which internal benefit increased from 898 m3 to 1084 m3, external benefit increased from 1537 m3 to 1800 m3. So the internal value of ecological services by soil and water conservation was higher than external value, but external use value was higher than internal value. At the same time, the ecological external services increased more rapidly than internal services.According to above 4 kinds of evaluation, the marginal ecological services of forest was higher than others, the following were terrace and orchard respectively, and the marginal ecological services of grassland was the lowest. The main service function of farmland and orchard were internal services and economic benefit. The main service function of forest and grassland were external services and ecological or social benefit.The indexes system to evaluate benefit of soil and water conservation based on the system theory showed that the degree of realization in the comprehensive control soil and water loss increased from 65.96% in 1997 to 72.90% in 2004. The degree of realization in social benefit is higher than others. The degree of realization in ecological benefit enhances fastest, especially the improvement of control degree and vegetation coverage was prominent. At present, basic farmland and grain per capita have achieved the target value, and control degree and vegetation coverage have achieved that 70%-90%t of the target value. However, the degree of realization of indexes such as soil erosion modulus, income per capita, labor productivity, land productivity yet was low, which would be emphases in the future work.There were some consistencies between the evaluation of comprehensive benefit in soil and water conservation based on the ecological services theory and system theory. Generally speaking, the evaluation of soil and water conservation based on the theory of ecological services is more scientific and systemic. The character of comprehensive benefit evaluating in soil and water conservation based on system theory is distinguish function, which can point out the main problems in the soil and water conservation.In this article, the theories and methods of comprehensive benefits evaluation for soil and water conservation based on the theory of ecosystem services were theoretically discussed. The application of ecosystem services assessment was expanding. The methods and models of comprehensive benefits evaluation for soil and water conservation according to the theory of ecosystem services were established. The basic parameters in the models were determined. The empirical study was established. The main problem and solving methods of restricting the improvement of ecosystem services were discussed. The previous purpose of this thesis has basically achieved. On the foundation of former research, the comprehensive benefits evaluation for soil and water conservation according to the theory of ecosystem services was proposed.更多还原