【作者】 柳毓梅；

【导师】 尹怀宁；

【作者基本信息】 辽宁师范大学 ， 环境科学， 2007， 硕士

【摘要】 随着点源污染得到逐步控制,非点源污染已经成为水环境污染的主要原因,其中又以农业非点源污染贡献率最大。农业非点源污染是指在农业生产活动中,农田中的土粒、氮素和磷素等营养物质、农药以及其他有机或无机污染物质,在降水或灌溉过程中,通过农田的地表径流、农田排水和地下渗漏,使大量污染物质进入水体,造成的水环境污染。大沙河是普兰店境内一条主要河流,大沙河流域面积964平方千米,长96.5千米,平均坡降1.34‰,径流量2.60亿立方米,径流深269.7mm。流域内以耕地为主要用地类型。农业非点源污染已经成为大沙河水质恶化的主要原因之一。因此,对该流域进行农业非点源污染研究对大沙河水环境的污染防治具有重要意义。本文在国内外农业非点源污染研究的基础之上,通过调查询问、监测分析和粗略估算等方法对普兰店大沙河流域的农业非点源污染情况进行了研究,主要研究该流域总氮TN、总磷TP的污染情况。本研究选取普兰店大沙河流域5个采样点,从上游到下游分别为元台、八家子、后线石、海皮大桥、后大院。通过对枯水期和丰水期两次采样的检测结果分析研究,得出总氮TN、总磷TP的污染情况。枯水期和丰水期两次检测,元台TN达到Ⅱ类水质标准;八家子、后线石、海皮大桥TN达到Ⅲ类水质标准;后大院TN达到Ⅳ类水质标准。TP均在Ⅱ类水质标准以上。造成这一状况的主要原因是大沙河流域农业的面源污染、工业的点源污染以及沿岸生活污水的排放。根据大连市农业非点源污染背景的研究,农业的面源污染是引起大沙河流域TN值增大的主要污染原因。从上游向下游水质TN浓度呈逐渐增大趋势,TN变化与流程相关性明显。八家子断面TN浓度增大幅度较大可能与该断面水量较少,河流自净能力降低有关。后大院断面TN浓度最高,超过地表水Ⅲ类水质标准,主要是由于后大院断面位于大沙河和其支流夹河交汇下游,上游氮素都随地表径流汇入大沙河,造成TN浓度显著增高。枯水期TN值略高于丰水期,主要是由于枯水期河水流量小、流速低,水体自净能力比较弱。同时春季施肥后的降雨过程也使大量氮素随地表径流流失,也是造成TN值高的原因。更多还原

【Abstract】 Along gradual controlling the point source pollution, the non-point source pollution has become a majority of water contamination. Among non-point source pollutions, the agricultural non-point source pollution is the biggest one. The agricultural non-point source pollution is defined to be the runoff transports of constituents include the nutrients, the agricultural chemicals and soon nitrogen and phosphorus element and all that are organic or the inorganic pollution matter from diffuse sources on the land to streams. Through the farmland surface runoff, the agricultural drainage and the underground leakage, cause the water environmental pollution.The Dasha River is the main river in Pulandian. The area is 964 square kilometers, and the length is 96.5 kilometers. Average slope is 1.34‰, diameter current capacity 260 million cubic meters, and the depth is 269.7mm.In the basin plants crops is mainly type. The agricultural non- point source pollution already became one of main reasons which the Dasha River quality worsened. Therefore, conducting the agricultural non- point source pollution research to this basin is valuable.This paper summarizes the state of the agricultural non-point source pollution research at home and abroad, research the Pulandian the Dasha river basin agricultural non- point source pollution situation. Mainly studies are about the total nitrogen (TN) and the total phosphorus (TP) pollution situation.This research selects 5 sampling spots, from upstream to downriver respectively after Yuan Tai, Ba Jiazi, Hou Xianshi, Haipi Bridge, Hou Dayuan. The dry season and the abundant water time two examinations.The TN of Yuan Tai achieves II water-quality standard, The TN of Ba Jiazi, Hou Xianshi,Haipi Bridge achieve III water-quality standard; The TN of Hou Dayuan achieves IV water-quality standard. The main reason is the agricultural non- point source pollution of the Dasha River basin and the industry point source pollution. According to the Dalian agriculture non- point source pollution background research, the agricultural non- point source pollution the main pollution reason which increases the TN of the Dasha River basin.The TN increases from the upriver to the downriver. Ba Jiazi cross sections TN density increases the scope to be comparatively greatly possible with this cross section water volume to be less; the rivers reduce from only the ability concern. The latter yard cross section TN density is highest, surpasses the surface water III water-quality standard.The dry season TN value slightly is higher than the abundant water time, mainly is because dry season river water current capacity small, speed of flow is low, the water body quite is only weak from the ability. In spring the apply fertilizer after rain causes the nitrogen run off along with the surface, also creates the TN higher.更多还原