【作者】 杨志敏；

【导师】 魏世强；

【作者基本信息】 西南大学 ， 农业资源利用， 2009， 博士

【摘要】 三峡库区是重庆市重要的农业经济生态区域和国家生态环境建设重点治理区域,其生态环境质量不仅涉及到三峡工程的长期安全运行,也关系到本地区乃至全国的生态、经济和社会发展。近年来,三峡库区农业生产有了飞速的发展,农村生活也有了很大的改善,但非持续发展、高消耗的农业生产与生活方式依然广泛存在,由此带米的农业资源环境问题积重难返,其中农业面源污染在相当长的时期内已成为制约农业可持续发展的重要因素之一,已引起国家和地方政府的高度重视。虽然三峡库区重庆段农业面源污染的研究较多,但利用“压力-状态-响应”模型分析三峡库区农业面源污染还是首次。本文首先构建了农业面源污染的“压力-状态-响应”模型,随后在区县级尺度上,采用清单分析方法,核算了三峡库区重庆段21个区县化肥施用、有机肥施用、农作物秸秆、畜禽养殖、农村生活污水、生活垃圾和农田侵蚀等7个来源对农业面源污染COD、BOD₅、TN、TP排放负荷及其贡献;评价农业面源污染的负荷程度;确定农业面源污染的主要污染物、主要污染源、主要影响因子、主要污染区域:确定农业面源污染的空间与时间序列特征。然后采用灰色模型预测了农业面源污染的发展趋势,在此基础上,计算了农业面源污染环境容量及其削减量。最后从沼气为纽带的循环农业角度,探讨了循环农业的发展度、协调度、障碍度及其与农业面源污染负荷的耦合模型。论文最后以涪陵区王家沟小流域为案例,重点探讨了发展户用沼气池对农业面源污染削减的响应,从而为重庆市制定农业面源污染防治、三峡库区水环境保护政策和管理策略提供科学依据。通过对农业面源污染的系统研究,引入了农业面源污染系统的压力-状态-响应（P-S-R）的概念模型,农业面源污染的排放量与排放系数可视为“压力”;由面源污染排放引起的水质变化可视为“状态”;由此反馈的人类活动可视为“响应”。根据该概念模型,设计了农业面源污染压力-状态-响应模型中基于污染源的理论指标体系和基于污染物的实际指标体系。理论指标体系中,压力指标为化肥、有机肥、农作物秸秆、畜禽养殖、农村生活污水、生活垃圾和农田侵蚀的等标排放系数,状态指标为化肥、有机肥、农作物秸秆、畜禽养殖、农村生活污水、生活垃圾和农田侵蚀等排放造成的质量指数,响应指标为化肥使用削减水平、有机肥使用水平、作物秸秆利用率、畜禽粪便利用率、生活污水处理率和生活垃圾处置率。实际指标体系中,压力指标为COD、BOD₅、TN、TP的实物绝对排放量、等标绝对排放量、等标相对排放量（国土基、产值基、人口基）;状态指标为地表水COD、BOD₅、TN、TP的浓度以及由此产生的地表水质综合指数、地表水质等级;响应指标为地表水环境容量与削减量、循环农业测度、户用沼气响应参数及沼气普及率。采用清单法核算2007年三峡库区重庆段农业面源污染负荷,由化肥施用、有机肥施用、秸秆排放、畜禽养殖、生活污水、生活垃圾、农田侵蚀等7个污染源排放的COD、BOD₅、TN、TP量分别为26.64×10⁴、14.71×10⁴、8.07×10⁴、1.52×10⁴t/a,其污染排放量均超过当年工业、生活排放的总和。其等标绝对排放量分别为53555、12739、6492、120325、11086、917、1672t/a。畜禽养殖排放最多,其次为化肥施用、有机肥施用和生活污水。全段基于国土面积的等标相对排放量为5.01t/km²,其中种植业、养殖业、村民生活和农田土壤侵蚀分别排放1.91、2.74、0.32、0.03t/km²,说明农业面源污染主要由畜牧养殖和农田种植造成。以三峡库区重庆段COD、BOD₅、TN、TP的实物绝对排放量为基础,暂不考虑水体净化过程,计算地表水COD、BOD₅、TN、TP的排放浓度,由此推导出三峡库区重庆段因农业面源污染导致的COD、BOD₅、TN、TP的平均浓度分别为10.04、5.44、2.98、0.67mg/L。据此确定水质污染严重的区县是沙坪坝区、大渡口区、巴南区、江北区和江津区,全部位于三峡库区重庆段上游;污染较轻的区县则是巫溪县、石柱县、巫山县、奉节县和开县,全部位于三峡库区重庆段下游（核心区）。集对分析认为,三峡库区重庆段中,农业面源污染理论负荷（不考虑水体净化过程）将会使奉节、巫山、巫溪、石柱等四县水质接近Ⅱ类;沙坪坝、巴南等两区水质接近劣Ⅴ类,其余15个区县水质接近Ⅴ类。三峡库区重庆段农业面源污染的主要污染物是TP、TN,贡献率分别为40.08%和36.83%:主要污染源是畜禽养殖和化肥施用,贡献率分别为58.21%和27.24%;主要影响因子是农业总产值,贡献率达到90%以上。主要污染区域为大渡口区、沙坪坝区、渝北区、江北区和忠县。主要影响因子为农业产值,说明COD、BOD₅、TN、TP排放量主要由农业生产活动产生。三峡库区重庆段农业面源污染具有典型的空间与时间分布特征。空间方面,采用离差平方和分别对压力、状态以及压力-状态进行了聚类分析,有助于农业面源污染控制的分类指导。防治农业面源污染,既要预防面源污染“压力”,又要治理污染“状态”。时间方面,农业面源污染压力指标（实物排放量）没有明显的分形特征,而状态指标（水质浓度）则具有分形特征,由此以2005年为标志,将直辖以来三峡库区重庆段农业面源污染划分为两个时段。根据三峡库区重庆段农业面源污染的现状,建立了农业面源污染的灰色预测模型,测算出2010年因农业面源污染而排放COD、BOD₅、TN、TP的总量分别为268533、147976、81643、15013t/a。在此基础上,若按照地表水平均三类水域标准,测算出COD、BOD₅、TN、TP的水环境容量分别为575096、115019、28754、5750t/a,污染物削减量分别为173956、95859、52889、9726t/a,并按照污染分担原则,分配到各区域、各污染源、各污染物等。循环农业对农业面源污染有着深刻的影响,循环农业的障碍度与农业面源污染的压力指数与相关关系较为显著,即障碍度越大,农业面源污染风险越大,意味着要想削减农业面源污染负荷,就必须克服循环农业障碍因子。在循环农业因子中,主导影响因子是代表畜牧业的粪便承载系数、代表种植业的耕地面积和代表农民生活的人均收入,其中粪便承载系数显示抑制作用,而耕地面积和人均收入则促进面源污染的加重,且它们均以直接作用的形式影响农业面源污染。以沼气为主导的循环农业对化肥施用、有机肥施用、农作物秸秆、畜禽养殖、农村生活污水、农村生活垃圾、农田侵蚀等7个污染源的控制既有直接作用,也有间接作用;既有促进作用,也有抑制作用。1个8～10m³的户用沼气池全年可减少COD230.65kg、BOD₅146.87kg、TN38.00kg、TP11.84kg的污染物进入水体。王家沟小流域实证研究表明,2008年该流域农业面源污染物COD、BOD₅、TN、TP的绝对排放量分别为12099、6414、1780、327kg,主要污染物仍然为TN、TP,主要污染源仍然为畜禽粪便、化肥、作物秸秆。COD、BOD₅、TN、TP年平均浓度分别为22.23、11.44、3.15、0.58mg/L,与实测浓度无显著差异,说明大尺度的农业面源污染负荷计算与小尺度的农业面源污染实测是相容的。为了使面源污染物达标,在考虑水环境容量的基础上,需要新建户用沼气池32口,最终沼气池入户率将达到49.2%。论文的特色之处在于:（1）采用压力-状态-响应模型全面分析农业面源污染,建立了农业面源污染压力-状态-响应模型中基于污染源的理论指标体系和基于污染物的实际指标体系;（2）将基于清单法的大尺度农业面源污染负荷测算与小尺度实测相结合,定量表征各农业面源各污染源的负荷贡献。（3）从数量化角度探讨沼气、循环农业对农业面源污染削减的响应关系,确立了户用沼气对农业面源污染削减的响应参数。但由于大部分数据来源于各种相关统计年报上的“面”上资料和现场抽样调查访问的“点”上资料,今后应对有关由计算所得的数据进行实际样品的抽样验证,以及运用释放动力学来优化污染物的“入河系数”等。更多还原

【Abstract】 The Three Gorges reservoir area was an important reginon that was considered as agricultural eco-economic in Chongqing and eco-environment construction in China. Its eco-environmental quality not only related to Three Gorges engineering but also development of economy, ecology and society. Recenty, the agricultural production of Three Gorges reservoir area had been largely developed; rural economic had been largely improved. But the agricultural production and living model character as non-sustainable development and high consumption extensive exist. The environmental problem of agricultural recourses, espeicallly, agricultural non-point source pollution （ANPSP） had been restricted agricultural sustainable development as an important factor and aroused nation and local governments high regard. The research of ANPSP of Three Gorges reservoir area was relatively more. But the analysis of ANPSP in Three Gorges reservoir area by pressure-state-response model （P-S-R） was just first.Firstly, the P-S-R model was constructed on the systematical researches of ANPSP. Subsequently, the discharge amounts of COD, BOD₅, total nitrogen （TN） and total phosphor （TP） was accounted by the list analysis on the scale of districts （counties） from the 7 sources of ANPSP such as chemical inorganic fertilizers, organic fertilizers, crops straw, stockbreeding, domestic sewage, domestic wastes and soil erosion, the degree loading of ANPSP was evaluated. The case of 21 districts （counties） was used to determine the priority pollutants, the priority pollution source, the priority affecting factors, the priority contaminated area and the character space-time of ANPSP in Chongqing section of the Three Gorges reservoir area （CSTG）. Then, the direction of ANPSP was forecasted by using the gray model, the environmental capacity and reduction of ANPSP was accounted basic on gray model. development degree, correspond degree, handicap degree and coupling medal of ANPSP loading was discussed form the circular agriculture attached by biogas. Finally, the response of reduced NPSP from developing door biogas was discussed mainly on the case of Wangjiagou small valley in Fuling District. Thereby scientific basis was offered to establishing ANPSP prevention and protecting Three Gorges reservoir.The P-S-R model was introduced by systematical researches on ANPSP, in which the discharge amount and its coefficient of ANPSP could be regard as "pressure", the change of water quality could be regard as "state", and feed backed human activity could be regard as "response". Pollution exoteric index system and practice index system in the P-S-R model of ANPSP was designed basing on this model.The discharge amounts of COD, BOD₅, total nitrogen （TN） and total phosphor （TP） was accounted by the list analysis on the scale of districts （counties） from the 7 sources of ANPSP such as chemical inorganic fertilizers, organic fertilizers, crops straw, stockbreeding, domestic sewage, domestic wastes and soil erosion, the absolute discharge amount of COD, BOD₅, TN and TP from ANPSP were 266.4, 107.1, 80.7, 15.2 thousand tons per year, respectively. Thereinto, the let quantity of COD exceeds the summation of industry and living of current-year in CSTG.The discharge amount in equivalent standard for pollutants source that accounted on the scale of districts （counties） from the 7 sources of ANPSP such as chemical inorganic fertilizers, organic fertilizers, crops straw, stockbreeding, domestic sewage, domestic wastes and soil erosion were 53555, 12739, 6492, 120325, 11086, 917, 1672t/α, respectively. The discharge amount of aquiculture was furthest, secondly were chemical inorganic fertilizers, organic fertilizers and domestic sewage.The comparatively discharge amount in equivalent standard for country area of CSTG at 2007 was 5.01t/km, Thereinto, The let quantity of planting, breeding, living, and spontaneousness erosion were 1.91, 2.74, 0.32, 0.03t/km, respectively. Indicating ANPSP was mainly brought by stockbreeding and farmland planting.The let concentration of COD, BOD₅, TN, TP was accounted base on them absolutely let quantity of CSTG, thereout, average concentration of COD, BOD₅, TN, TP leaded by ANPSP in CSTG were 10.04, 5.44, 2.98, 0.67mg/L, respectively.The bad pollution water quality of CSTG were Shapingba, Dadukou, Banan, Jiangbei and Jiangjing that placed the Three Gorges reservoir area upriver, Wushang, Shizhu, Wuxi, Fengjie, Kaixian, placed the Three Gorges reservoir area lower reaches （core area）, were polluted rather ethereal, set pair analysis indicted that the water quality of Wushang, Shizhu, Wuxi, Fengjie were II level in CSTG, The rest of 15 countries were V level.Mainly pollutant of ANPSP in CSTG were TP, TN, contribution rate were 40.08% and 36.83%; mainly pollution sources were stockbreeding and chemical inorganic fertilizers, contribution rate were 58.21% and 27.243%; Mainly influence factor was total Agro-production value, was more than 90%; Mainly pollution areas were Dadukou, Shapingba, Yubei, Jiangbei and Zhongxian; mainly influence factor was agro-production value. Indicating the let quantity of COD, BOD₅, TN, TP produced from agro-production activity. The couping analysis of pollutant and pollution sources showed that stockbreeding provided COD, was mainly pollution sources, other sources provided BOD₅, TN, TP.Using squares of deviation, Clustering analysis, was adopted for analyzing the P-S-R of ANPSP in CSTG, helped to classify guidance of ANPSP. Preventing ANPSP must defend the "pressure" as well as fathered the "state" of pollution. Only seeking both temporary and permanent solutions and classifying guidance, Can radically prefabricated the exasperate trend of ANPSP.The gray model of ANPSP, forecasted concentration of COD, BOD₅, TN, TP leaded by NPSP were 268533, 95859, 52889, 9726t/α, was established base on the station of NPSP in CSTG. Moreover, those pollution was distributed every areas, every polluted sources, every pollutions, and so on. Circular Agriculture, its obstacle degree has a markedly correlation with press index of NPSP, could profoundly affected ANPSP. Obstacle degree has a direct proportion with the risk of ANPSP, that is to see only conquered the factor of agricultural obstacle degree, can reduced the loading of ANPSP.In the circular agricultural factors, dominant factor delegated the dejecta bearing index of stockbreeding, the area of planting and average income of people’s living, hereinto dejecta bearing index showed restrain, but the area of planting and average income accelerated aggravate of ANPSP.Circular agricultural dominant by biogas could controlled 7 sources of ANPSP such as chemical inorganic fertilizers, organic fertilizers, crops straw, stockbreeding, domestic sewage, domestic wastes and soil erosion, had immediacy effect as well as indirectly, had accelerate effect as well as restraint. An biogas of 8-10 m³ could reduced COD, BOD₅, TN, TP to water, were 230.65, 46.87, 38.00kg, T11.84kg, respectively.Taking Wangjiagou small valley in the Fuling District for example, it showed that the absolute discharge amount of COD, BOD₅, TN and TP from this ANPSP were 12099, 6414, 1780, 327kg, mainly pollutant were TN and TP; mainly polluted sources were chemical inorganic fertilizers, crops straw, stockbreeding which discharge average concentration of COD, BOD₅, TN and TP were 22.23, 11.44, 3.15, 0.58mg/L, it had not markedly difference with measure. Indicting that account of loading ANPSP had a better consistent with fact measure. In order to make pollution emission below standard and taking waterenvironmental capacity into consideration, Wangjiagou small valley need to built 32 biogas that using ratio reached 49.2%."P-S-R" model had been firstly used to analysis ANPSP, pollution exoteric index system and practice index system in the P-S-R model of ANPSP was established basing on this model.Though feature of this paper consisted: （1） "P-S-R" model had been firstly used to analysis ANPSP, pollution exoteric index system and practice index system in the P-S-R model of ANPSP was established basing on this model. （2） The forecast of loading ANPSP based on the list had been integrated with fact measure to quantitated Ratio of loading ANPSP. （3） Biogas and circular agricultural affecting response of ANPSP reduction was discussed form quantification, parameter of door biogas responding form ANPSP reduction was established. But a majority of "area" data come from various related statistical annual reports and "dot"data come form sampling intermigration and interview, for the future, all data from account should be sampling inspected, "river load ratio" of pollutant should be optimized by release kinetics.更多还原