【作者】 刘光栋；

【导师】 吴文良；

【作者基本信息】 中国农业大学 ， 生态学， 2004， 博士

【摘要】 本文针对现代集约化农业中，以资源环境投入换取农业产出效益的不可持续的发展模式，以华北集约化农业典型高产粮区—桓台县为例，定量评估农业生产的资源环境影响及其价值损失，以期为农业技术、政策提供成本效益分析工具，为区域农业绿色GDP核算提供理论和技术支持。 采用系统设计方法，围绕农田生态系统中水分及碳氮的物质平衡过程，通过理论分析、监测调查和模型模拟的方法对区域农业资源环境经济成本进行评估，比较筛选适宜评估农业环境问题的方法，并归纳出实施区域农业生产资源环境成本评估的程序化步骤。 研究应用大量的一手调查数据和统计资料，进行实证分析，取得如下主要研究成果： ①农田生态系统中碳、氮和水分循环与平衡过程是农业环境影响评价和环境损失评估的物质基础；根据环境价值评估的需要，划分农业生产的外部成本为资源退化性损失和环境污染性损失；应用资源环境经济学理论于区域农业生产环境问题，就集约化农业普遍存在水资源耗竭、地下水面源污染、土壤肥力变化及农田温室气体排放等分别采用水资源价值的稀缺增值评估法、人力资本法、生产函数法和成果引用法等若干方法予以评估了相应的价值损失。 ②基于理论分析和评估实践，提出了包括区域农业模式划分、外部影响筛选、影响的定量、影响的货币化和环境成本加总的五步评估流程及区域农业生产成本效益分析模型化框架；归纳了评估所必须的自然资源环境参数、模型化参数、社会经济参数构成的参数支持系统；初步提出组织管理这些参数的GIS数据库四层结构，为区域农业环境损失评估向模型化、程序化、电算化方向发展，开发区域农业资源环境成本评估模型软件奠定了理论基础。 ③针对农业用水加剧区域水资源耗竭的稀缺特征，提出区域地下水资源相对农业的稀缺增长模型。应用GIS技术分析区域地下水硝酸盐污染的空间分布发现：区域农业硝酸盐污染有非均衡的空间分异特征，即地下水分化为硝酸盐净输出的源区和净输入的汇集区。污染空间分布与潜水位等值线的一致性表明地下水流向在农业面源污染空间分异过程中的主导作用，支持了农业面源污染实施流域作为生态单元管理的对策。 ④采用不同方法，比较评估桓台县2002年农业生产的外部不经济性损失为3089.3～4778.7万元／a，平均单位耕地产生外部损失价值为1101.5～1703.9元/a。其中，占第一位的是水资源成本2608.8～4232.9万元／a，地下水硝酸盐面源污染损失为860.8～1170.1万元／a。由于过去10多年土壤肥力的持续改善，产生了490.9～949.1万元／a的正效应。参照美国的固定和减排CO₂成本评估该温室气体排放所造成的外部经济损失大约是110.6～324.8万元／a。按桓台县当年小麦和玉米单产水平计算，粮食生产的边际外部环境成本为0.09元／kg。 ⑤借助DAISY模型，初步模拟小麦—玉米两粮轮作模式，在常规耕作管理基础上，模拟分析减少氮肥30％、减少灌溉50％、改小麦玉米秸秆双还田为单还田等条件下的环境损失变动。减少肥水投入条件下的外部成本变化分别降低4％和36.7％，但伴随外部损失的降低，相应导致减产21.3％和21.9％。因此指出农业生产和环境的双赢必须依赖科学技术的可持续战略。更多还原

【Abstract】 Considering the unsustainability of modern intensive agriculture for economic return in the price of resources and environment, this dissertation aimed at assessing physical impacts induced by intensive farming and at evaluating the externality loss of a regional agriculture. To achieve these objectives, a case study was done on a typical cereal high-yielding region, Huantai County, North China. The research targets were to make a calculation tool for cost-benefit analysis of agricultural techniques and policies, as well as to provide methodology for green GDP accounting of agricultural regions.This research was systematically designed with focus on analyzing the dynamic budgets of water, carbon and nitrogen in agro-ecosystem. Theoretical analysis, environmental monitoring and surveys together with model simulations were integrated in order to fulfill the calculation of the environmental cost of agriculture. Different approaches were compared for sieving suitable ones for evaluating specific agriculture related environmental problems. Finally, a universal procedure was summed up to estimate environment cost of agriculture in the investigated region.Based on a large amount of first-hand and statistical data, full and accurate case study, the important output of the studies were concluded as the followings:(1) The budgets and cycles of water, carbon and nitrogen in the agro-ecosystem are the material bases for determining the physical impacts of agriculture and for evaluating the corresponding environmental cost. For the purpose of externality evaluation, the external impacts were divided into two types, viz. resource degradation loss and environmental pollution loss. By employing the theories of resource economics and environmental economics, the value of the agriculture related externalities were estimated. A method named Scarcity Value Increment method, Human Capital Approach, C-D Production Function as well as Benefit Transfer methods were adopted to valuate the cost and/or benefit of groundwater resource depletion, non-point source pollution, soil fertility changes and green house gas emission from farmland.(2) In the case study, three basic supporting database consisting natural, social-economic and model parameters were summarized to complete an evaluation. These databases were supposed to be organized in a four-layer-structure GIS format. A general procedure for environment evaluation composed of five steps, namely farming pattern classification, impacts sieving, physical impact quantification, monetization and aggregation. Based on these results, a framework was established for modeling, programming and computerizing environmental valuation for regional agriculture in the future. They can also be used as the algorithmic basis for software development of agricultural environment evaluation.(3) Concerning the exhausting extractable groundwater as a consequence of intensive agriculture, aScarcity Increment model was set up to describe the dynamic depletion. The surface analysis techniques by GIS were used to analyze the regionally spatial distribution of nitrogen pollution in the groundwater. It was discovered that nitrate pollution was unevenly distributed. It was assumed that some areas might have gradually developed into source area with nitrate outflow, while the others into catching areas receiving nitrate out flowing from the former. The spatial consistence between nitrate pollution distribution and groundwater isoiines probably indicated that the groundwater flow might dominate the regional pollution differentiation. This conclusion strongly supports that countermeasures considering watershed as an ecological unit are necessary in order to control agricultural induced non-point pollution.(4) The externalities of agriculture in Huantai County were evaluated by several approaches. In 2002, the total net externality loss amounted to 30.893 ~ 47.787 million yuan/a, equivalent to 1101.5-1703.9 yuan/hm2 annually. Among the externalities, water resources accounts the majority, 26.088~更多还原