【作者】 李晓；

【导师】 徐龙君； 邓春光；

【作者基本信息】 重庆大学 ， 环境工程， 2008， 硕士

【摘要】 三峡水库蓄水成库后,长江天然河道属性发生改变,形成典型的狭长型水库,特别是库区各条支流因受到干流水位顶托,出现长短不一的回水河段,流速十分缓慢,水体出现不同程度的富营养化,严重影响了库区的水环境质量,并直接对库区生态环境和饮用水安全构成威胁。本课题在大量监测调查数据的基础上,对三峡库区主要一级支流的富营养化水平进行预测和水质安全评估,提出相应的对策措施。2006年对长江干流常年回水区监测结果表明,23条一级支流回水区差于Ⅲ类水质的断面约占两成。库区主要一级支流回水区水体综合营养状态为贫-中营养的断面所占比例约为80%,富营养以上的断面约占20%。回水中段富营养化情况明显重于回水尾段。近几年规模化的“水华”现象都始发于3月～4月,主要发生区域集中在离三峡大坝较近的巫山县、奉节县和云阳县,且水华现象的程度、时间和范围有逐年增长趋势。以乌江、小江、大宁河三条典型支流为代表,统计和计算水体的主要污染负荷,进行富营养化水平预测和类比分析后得出,三峡库区支流出现富营养化的区域,主要在水库常年回水区(涪陵以下江段),有越靠近坝首富营养化加重之势,且主要在支流回水腹心区,特别是水面开阔的低流速区,将是富营养化的高发地段。从上游到下游,富营养化呈现低―高―较低或者轻―重―较重的分布态势。在对敏感的饮用水源点进行搬迁后,库区支流回水区内水质是较安全的。通过富营养化趋势预测和水质安全评估,从饮用水安全保障、库区支流回水区富营养化防治技术和“水华”应急处理三方面提出了环境管理制度保障、控制与防治技术等若干对策措施。更多还原

【Abstract】 After the water storage, there are drastic changes in hydrological situation of Three Gorges Region and every branch river, and the Yangtse River become as a long and narrow reservoirs Area. The backwater region of every binnacle flows slowly, and been an eutrophication sysytem more or less. The water quality of reservoirs Area was weakened seriously, and imperiled the ecological environment and the drinking reliability of people. Based on copious examination data, intimate prognosis about eutrophication and security assessment were presented in this paper, and several strategies followed.Water quality monitoring data of backwater region on Yangze River 2006 showed that, 20 percent reached water quality beneathⅢlevel among 23 branch rivers in the three gorges reservoirs region. The branch rivers of 80% were in a low-medium eutrophication, and those of 20% were in high eutrophication. The richer fertiliser in the middle areas of binnacle backwater region was moreobviously serious than that in extremity area. In the past years, macroscale plankton bloom always broken out in March and April. Plankton bloom locality are chief focused at Wushan, Fengjie and Yunyang which are near by the the Three Gorges Dam, and its degree is deeper, area is wider. Taken three binnacles of Da’ning, Xiaojiang and Wujiang as models, water pollution load was accounted. After a foretaste analysis of the eutrophication lever, it considered that the eutrophication area was mostly at the all-the-year backwater region (lower reaches of Fulin). The more serious richer eutrophication is, the near it closes to the dam. At the backwater ventro-zone of branch river, where assumes unclosed and sluggish current, eutrophication would be much more serious. From upper reaches to tail, it appears a low-high-little distribution. After the sensitive drinking-water sources sites have been relocated, the quality security of backwater region would achieve.The several strategies at three aspects as drinking-water security, technological measure to control eutrophication in backwater region and emergency disposal to plankton bloom have been brought by the concludsions on the prognosis of eutrophication and security assessment,.更多还原