太湖流域农业面源污染治理的对策研究
管 栩
（南京师范大学地理科学学院,南京210046）
摘要：农村面源污染在很多区域已超出了点源污染对水环境的危害程度。但到目前为止，农业面源污染问题仍没有引起社会的广泛关注，政策法规滞后。本文通过调查对太湖各湖区水质进行调查，分析近年来水质变化的相关数据，探讨太湖流域内农业面源污染发生的途径，结合区域农业生产管理的现状，借鉴国内外面源污染的管控经验，从工程治理、农业生产布局优化和经济激励措施等方面构建了太湖水治理的对策。
关键词：面源污染 太湖 治理对策
The research of the countermeasures on agricultural non-point
source pollution in Taihu Lake
Guanxu
(Nanjing Normal University, Nanjing 210046)
Abstract：Rural non-point source pollution has replaced point source pollution as an important source of water pollution.But non-point source pollution has not been widespread concerned by the community so far, the policies and regulations on agricultural nonpoint source pollution control are seriously lagging behind. This paper investigates the water quality of Taihu Lake and analysis the changes in water quality. Then the paper researched the means in agricultural nonpoint source pollution and combine the status of regional agricultural production and management ,draw on the non-point source pollution control experience of home and abroad .The paper described countermeasures on agricultural non-point source pollution in Taihu Lake from project governance, agriculture and economic measures.
Keywords：non-point source pollution Taihu Lake countermeasures
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目录
1.绪论 ························································································································· 4
1.1研究背景 ········································································································· 4
1.2国内外研究现状 ····························································································· 4
1.2.1国内外综述 ·························································································· 4 1.2.2国外研究现状 ······················································································ 4 1.2.3国内研究现状 ······················································································ 4 1.3本课题研究内容 ····························································································· 5
2.太湖水质情况······································································································· 5
2.1太湖简介 ········································································································· 5 2.2太湖水质情况 ································································································· 5
2.2.1太湖年度水质情况 ·············································································· 6 2.2.2太湖月度水质情况 ·············································································· 7 2.3太湖九大湖区 ································································································· 8
2.3.1湖区各月份水质情况 ·········································································· 9 2.3.2湖区各月份富营养化情况 ·································································· 9 2.3.3湖区各月份蓝藻情况 ·········································································10 2.4湖区水质分析 ································································································10
2.4.1入湖河流 ·····························································································10 2.4.2湖区水生生物情况 ············································································· 11 2.4.3湖区水质总结 ····················································································· 11
3.面源污染途径······································································································12
3.1太湖面源污染综述 ························································································12 3.2农业面源污染途径 ························································································12
3.2.1种植业污染 ·························································································12
3.2.1.1化肥污染 ··················································································12 3.2.1.2农药污染 ··················································································12 3.2.2养殖业污染 ·························································································12
3.2.2.1禽畜养殖污染 ··········································································12 3.2.2.2水产养殖污染 ··········································································13
3.3农业面源污染排放系数 ················································································13 3.4各湖区面源污染 ····························································································13
3.4.1各湖区地理特征 ·················································································13 3.4.2各湖区污染情况 ·················································································14
4.国内外治理经验 ·································································································14
4.1国外农业面源污染治理途径 ········································································14 4.1.1美国治理措施 ·····················································································14
4.1.1.1政策措施 ··················································································15 4.1.1.2经济措施 ··················································································15
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4.1.1.3工程项目措施 ··········································································15 4.1.1.4技术措施 ··················································································15 4.1.2欧盟治理措施 ·····················································································15
4.1.2.1政策措施 ··················································································15 4.1.2.2经济措施 ··················································································16 4.1.2.3技术措施 ··················································································16
4.2国内治理措施 ································································································16
4.2.1宣传措施 ·····························································································16 4.2.2工程项目措施 ·····················································································16 4.2.3技术措施 ·····························································································16
5.治理措施 ···············································································································17
5.1生态工程措施 ································································································17 5.1.1生态坑塘 ·····························································································17
5.1.1.1生态坑塘功能 ··········································································17 5.1.1.2设计模式 ··················································································18 5.1.1.3设计实例 ··················································································18 5.1.2生态沟渠 ·····························································································18
5.1.2.1生态沟渠功能 ··········································································19 5.1.2.2设计模式 ··················································································19 5.1.3滨岸缓冲带 ·························································································19
5.1.3.1滨岸缓冲带功能 ······································································19 5.1.3.2设计要求 ··················································································19 5.1.3.3设计模式 ··················································································20
5.2农业优化措施 ································································································20
5.2.1种植业 ·································································································20
5.2.1.1保持水田面积 ··········································································20 5.2.1.2旱地栽培大幅压缩 ··································································21 5.2.1.3园地生产保持稳定 ··································································21 5.2.2畜禽养殖业 ·························································································21 5.2.3淡水养殖 ·····························································································21 5.3经济税费措施 ································································································21
5.3.1农户补贴 ·····························································································21 5.3.2农业税费 ·····························································································22
6结论和建议············································································································23 7.谢辞 ························································································································23 8.参考文献 ···············································································································24
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1.绪论
1.1研究背景
农村面源污染已经取代点源污染成为水环境污染的重要来源。但到目前为止，农业面源污染问题仍没有得到社会的广泛关注，国家关于农业面源污染治理的政策法规严重滞后。
目前，在农业生产过程中，化肥、农药施用过量及农膜、地膜的处理不当等一系列不合理的农业生产经营行为是导致农业面源污染的主要因素。
20世纪70年代以来，中国重要的湖泊和河流如太湖、三峡库区、滇池等富营养化问题严重。从太湖2006年的统计来看，来自农业面源污染的总氮、总磷和化学需氧量(COD)分别占到总量的60%~70%、50%~60%和30%~40%。太湖流域是中国人口最为密集的区域，水质下降以给地区的生活用水带来极大威胁，给生产和经济发展造成巨大损失。
在未来加大点源污染的治理政策下，工业和居民生活用水对环境的影响将逐渐减少，农业面源污染占污染的比重将变大。由于我国现阶段的环境管理主要建立在点源污染上，现阶段的农业管理体制对农业面源污染很难控制。农业面源污染已经滞后于农业现代化的进程，面源污染造成的危害也严重影响到居民生活话环境，甚至制约社会可持续发展，加大农业面源污染就迫在眉睫。
1.2国内外研究现状
1.2.1国内外综述
对农业面源污染的研究是一个渐进的过程。20世纪60年代以前，人们没有意识到农业面源污染的严重性，点源污染被认为是造成水体、土壤污染的重要原因。从20世纪60年代开始，学术界逐渐关注农业面源污染问题，20世纪70年代开始系统研究农业面源污染，并付诸实践。
1.2.2国外研究现状
国外农业面源污染的研究以1972年美国制定的《水污染控制法修正案》为标志划分为两个阶段。1972年以前，人们意识到农业面源污染，尤其是农药对土壤、水体生态环境的影响引起了人们的极大重视。1972年以后，随着美国《水污染控制法修正案》的制定，农业面源污染的研究有了深入发展。目前，国外有关农业面源污染经济学方面的研究主要集中在以下两个:农业面源污染的影响因素分析、减少农业面源污染的战略和对策研究。
国外对于农业面源污染影响因素方面的研究，起初关注农业面源污染的主控因子，发现气候条件、耕地质量、水利设施状况等都会对农业面源污染产生广泛影响。随后的研究开始较多关注引起农业面源污染的农户个体因素，包括农业生产资料价格、家庭收入、受教育程度、家庭结构及非农就业等方面的因素。
1.2.3国内研究现状
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国内的农业面源污染研究始于80年代的湖泊、水库富营养化调查和河流水质规划研究。先后在滇池、太湖、巢湖、镜泊湖、西湖、三峡库区等湖泊，以及沱江内江段、淮河淮南段、黄河兰州段、渭河宝鸡段、辽河铁岭段进行了探索性的研究，积累了有益的经验。
国内在面源污染的研究仍然集中在湖泊和村镇周边区域，通过建设生态坑塘和沟渠的自净能力等污水生态处理系统，同时进行相关控制效果的研究。人工生态坑塘塘系统和人工湿地等生态工程只能适用于平原地区、湖滨带、河岸滩、村镇周边等地形比较平坦的地带，在山区的研究还显得很少，例如太湖西部界岭山脉等地山区农业的氮磷流失就很少得到研究。
对农用地形成面源污染的研究主要研究化肥农药，普遍认为过量使用化肥农药和是导致氮磷大量流失的主要原因，据研究，化肥过量施用氮、磷流失分别占面源污染的95%和93%。但针对目前化肥大量施用的现实情况，对面源污染“源”的控制研究开展得非常少，对农业的优化设计研究的还较少。
对农用地面源污染从经济学角度考察农业面源污染的甚少。直至近期，部分学者才开始进行此类研究的尝试。我国在控制农业面源污染财政政策的研究、制定以及实施方面虽然做了一定的工作，取得了一些成果，但在总体上还是比较薄弱，只有少数学者进行了尝试。
1.3本课题研究内容
本文主要研究太湖面源污染现状及存在问题，包括太湖及流域内主要河流的水质情况和太湖流域内农业分布及生产结构，面源污染发生的途径。通过数据分析近年来水质变化情况，并从污染物和各湖区分析太湖水治理重点。通过搜集国内外面源污染治理的模式，提炼出太湖水治理方式。最后构建太湖水治理的模式，多方式结合，选出最优模式的结合。
2.太湖水质情况
2.1太湖简介
太湖位于长江三角洲南部，地处江南水网中心，是我国东部近海区域最大湖泊，也是我国第三大淡水湖。太湖属于平原水网区的大型浅水湖泊，面积为2428km2，湖岸线长达400km，平均水深只有1.89m,水位比较稳定，蓄水量44.28亿m3，是一个天然的巨型水库，不仅对全流域灌溉有很大作用，而且对流域城乡供水和航运有着重要的作用。
以太湖为中心的水系区域称太湖流域。流域范围北滨长江，东沿东海，南抵杭州湾，两靠天目山和茅山，流域面积为36895km2。流域位于东经120°8′~121°55′，北纬30°5′~32°8′，属于北亚热带[1]。
流域包括苏州、无锡、湖州等38个市县，相连通的河流计220余条。太湖流域自然条件优越，平原气候温和湿润，水网稠密，土壤肥沃，是我国重要的商品粮基地和三大桑蚕基地之一，也是我国重点淡水渔业基地。
农业面源污染对太湖氮磷的贡献率分别达到了83%和84%[2]，远远超过了工业和城市生活点源污染，来源于农田、畜禽养殖农村生活面源的总磷分别为19%、35%，总氮分别为29%、23%[3]。
2.2太湖水质情况
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