Water Quality Prognosis And Strategy To Secondary River Of 3-Gorges Reservoir Area

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 beneathâ…¢level 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,.