【作者】 刘晶；

【导师】 刘强； 荣湘民；

【作者基本信息】 湖南农业大学 ， 植物营养学， 2007， 硕士

【摘要】 近年来，湘江与洞庭湖水质同趋下降。本研究以氮、磷元素和有机污染物为主要对象，对湘江与洞庭湖水质进行了全年定点、定时连续的调查与评价，并分析了其水质变异的规律。研究结果如下：1、对湘江进行了36个站次的调查监测，总评劣于Ⅲ类水水质标准的有21次，占总次数的58.3％。内梅罗指数介于1.0～2.0的次数，即水质处于轻污染水平的次数达到10次，占总次数的27.8％。超标的项目主要是总磷（TP）和氨氮（NH₃-N）。2、湘江上游熬州断面劣于Ⅲ类水水质标准的次数达6次，占12次调查监测的50.0％；内梅罗指数介于1.0～2.0的次数，即水质处于轻污染水平的次数为1次，占12次调查监测的8.3％。湘江中游乔口断面劣于Ⅲ类水水质标准的次数达8次，占12次调查监测的66.7％；水质处于轻污染水平的次数为5次，占12次调查监测的41.7％。湘江下游鹿角断面劣于Ⅲ类水水质标准的次数达7次，占12次调查监测的58.3％；水质处于轻污染水平的次数为4次，占12次调查监测的33.3％3、对洞庭湖进行了45个站次的调查监测，总评劣于Ⅲ类水水质标准的次数高达41次，占总次数的91.1％，其中超Ⅴ类高达30次，占监测总次数的66.7％。内梅罗指数介于1.0～2.0的次数达到13次，占总次数的28.9％；内梅罗指数大于2.0的次数，即水质处于污染水平的次数为23次，占总次数的51.1％。超标的项目主要是总氮（TN）、总磷（TP）和氨氮（NH₃-N）。4、东洞庭湖君山断面12次调查监测均劣于Ⅲ类水水质标准，其中劣Ⅴ类高达9次，占12次调查监测的75.0％；内梅罗指数介于1.0～2.0和高于2.0的次数，即水质处于轻污染水平和污染水平的次数分别为3次和7次，分别占12次调查监测的25.0％和58.3％。洞庭湖出口桂花园断面劣于Ⅲ类水水质标准的次数达11次，其中劣Ⅴ类达7次，占12次调查监测的58.3％；水质处于轻污染水平和污染水平的次数分别为2次和6次，分别占12次调查监测的16.7％和50.0％。南洞庭湖万子湖断面劣于Ⅲ类水水质标准的次数达10次，其中劣Ⅴ类高达8次，占11次调查监测的72.7％；水质处于轻污染水平和污染水平的次数均为5次，均占11次调查监测的45.5％。西洞庭湖目平湖断面劣于Ⅲ类水水质标准的次数达8次，其中劣Ⅴ类高达6次，占10次调查监测的60.0％；水质处于轻污染水平和污染水平的次数分别为3次和5次，分别占10次调查监测的30.0％和50.0％。5、湘江与洞庭湖中总磷（TP）的贡献主要是由于颗粒态磷（PP）引起的，降水和农业活动是氮污染的主要影响因素，地表径流在一定程度上已成为氮和磷进入水体的主要途径，农业非点源污染是湘江与洞庭湖氮、磷污染物的主要来源之一。而且在洞庭湖，有机污染物质进入水体的主要途径为地表径流，伴随着有机污染物进入水体，盐份也进入水体，非点源污染也是有机污染物的重要来源之一。6、总氮（TN）、溶解氧（DO）和电导率（EC）在各个断面之间的相关性最好，氨氮（NH₃-N）和氧化还原电位（Eh）次之。这表明氮污染物、DO和盐份具有相似的累积和消解特性，在治理时则表现为湘江上游水质的改善对下游水质的提高有直接的影响，对洞庭湖水质的提高也有一定的作用。7、湘江与洞庭湖污染指标值的时间变化规律有较为一致的特点，即在雨季和枯季污染物浓度会有明显的升高。从空间变化来看，湘江上游的污染物浓度普遍低于中游和下游，东洞庭湖污染物浓度比西洞庭湖和南洞庭湖污染物浓度的月间变化大。更多还原

【Abstract】 In recent years, the Xiangjiang River and Dongting Lake water quality has beendeteriorating. Seting seven sampling cross sections in Xiangjiang River and Dongting Lake,taking nitrogen, phosphorus and organic pollutants as main objective, the water quality wasmeasured and evaluated monthly from Apr.2006 to Mar.2007, and the water quality variationwas analyzed. The following achievements were obtained:1. In the 36 times measurement of the Xiangjiang River water quality, 21 times wereinferior to theⅢlevel of water quality standard, accounting for 58.3% of the total. The times ofNemero index between 1.0～2.0, which was in lightly polluted water quality level, reached 10,accounting for 27.8% of the total. The indices exceeding the standard mostly were totalphosphorus （TP） and ammonia nitrogen （NH₃-N）.2. In the 12 times measurement of Aozhou （the upriver sampling cross section inXiangjiang River） water quality, the times inferior to theⅢlevel of water quality standard upto 6, accounting for 50% of the total 12. The times of Nemero index between 1.0～2.0, whichwas in lightly polluted water quality level, was 1, accounting for 8.3% of the total 12. In the 12times measurement of Qiaokou （the sampling cross section in middle reaches of XiangjiangRiver） water quality, the times inferior to theⅢlevel of water quality standard up to 8,accounting for 66.7% of the total 12. The times in lightly polluted water quality level were 7,accounting for 58.3% of the total 12. The times inferior to theⅢlevel of water quality standardof Lujiao,which was the sampling cross section in the lower reaches of Xiangjiang River, up to7, accounting for 58.3% of the 12 times measurement. The times in lightly polluted waterquality level were 4, accounting for 33.3% of 12 times measurement.3. In the 45 times measurement of the Dongting Lake water quality, 41 times were inferiorto theⅢlevel of water quality standard, accounting for 91.1% of the total; the times inferior totheⅤlevel of water quality standard reached 30, accounting for 66.7% of the total. The times ofNemero index between 1.0～2.0, which was in lightly polluted water quality level, reached 13,accounting for 28.9% of the total. The times of Nemero index higher than 2.0, which was in polluted water quality level, reached 23, accounting for 51.1% of the total. The indicesexceeding the standard mostly were total nitrogen （TN）, total phosphorus （TP） and ammonianitrogen （NH₃-N）.4. There were 12 times measurement of Junshan sampling cross section in the EastDongting Lake, all of them were inferior to theⅢlevel of water quality standard, 9 times wereinferior to theⅤlevel of water quality standard, accounting for 75.0% of the total. The times ofNemero index between 1.0～2.0, which was in lightly polluted water quality level, were 3,accounting for 25.0% of the total 12. The times of Nemero index higher than 2.0, which was inpolluted water quality level, were 7, accounting for 58.3% of the total 12. The times inferior totheⅢlevel of water quality standard of Guihuayuan, which was the exit of Dongting Lake, upto 11; 7 times were inferior to theⅤlevel of water quality standard, accounting for 58.3% of 12times measurement. There were 2 times in lightly polluted water quality level and 6 times inpolluted water quality level, accounting for 16.7% and 50.0% of the total 12 separately. Therewere 11 times measurement of Wanzihu sampling cross section in the South Dongting Lake, thetimes inferior to theⅢlevel of water quality standard up to 10, and 8 times were inferior to theⅤlevel of water quality standard, accounting for 72.7% of the total 11. There were both 5 timesin lightly polluted water quality level and polluted water quality level, accounting for 45.5% ofall 11. There were 10 times measurement of Mupinhu sampling cross section in the WestDongting Lake, the times inferior to theⅢlevel of water quality standard up to 8, and 6 timeswere inferior to theⅤlevel of water quality standard, accounting for 60.0% of the total 10.There were 3 times in lightly polluted water quality level and 5 times in polluted water qualitylevel, accounting for 30.0% and 50.0% of the total 10 separately.5. The contribution of total phosphorus of the Xiangjiang River and Dongting Lake wasmainly due to particulate phosphorus cause. The main causes of nitrogen pollution wereprecipitation and agricultural activities. Surface runoff was the main channel of nitrogen andphosphorus entering the water in a certain degree. Agricultural Non-point source pollution wasone of the main sources of nitrogen and phosphorus pollutants of the Xiangjiang River andDongting Lake. The main channel of organic pollutants entering the water was surface runoff inDongting Lake. Along with organic pollutants into the water, salt entered the water, sonon-point source pollution was one of the important sources of organic pollutants. 6. The correlations of TN, dissolved oxygen （DO） and electric conductivity （EC） in allsections were the best; ammonia nitrogen （NH₃-N） and redox potential （Eh） were the second.These showed that the nitrogen pollutants, dissolved oxygen and salinity had similarcharacteristics of accumulation and digestion. When the water quality of upriver reaches ofXiangjiang River was improved, the water quality of lower reaches of Xiangjiang River wouldbe improved; the water quality of Dongting Lake would be improved also in a certain degree.7. There was a same characteristic in Xiangjiang River and Dongting Lake pollutionindices’ emporal variation. It was that the pollutants concentration would be significantlyincreased in the rainy and dry season. The spatial variation of pollution indices showed that thepollutants concentration in upriver of Xiangjiang River was generally lower than which inmiddle and lower reaches. The changes of the pollutants concentration in the East DongtingLake were bigger than which in the South and West Dongting Lake.更多还原