Key Laboratory of Ecological Effects of Hydraulic Engineering and Restoration of Aquatic Ecosystem of the Ministry of Water Resources, The Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan, Hubei Province, People's Republic of China.
Environ Sci Pollut Res Int. 2011 Aug;19(7):2849-59. doi: 10.1007/s11356-012-0791-6. Epub 2012 Feb 17.
From December 2008 to November 2009, an investigation of water quality was performed in the 70-km long downstream from Gezhouba Dam in Yangtze River.
Twelve sites in all were chosen. Nine parameters of water quality including the total phosphorus, the total nitrogen, chlorophyll a (Chl.a), nitrite, nitrate, ammonia, water temperature, DO, and pH were monitored almost monthly. The multivariate statistical technique (cluster analysis) and the nonparametric method (Kruskal-Wallis Test and Spearman's rank correlation) were applied to evaluate the spatiotemporal variations of water quality data sets.
According to the Chinese environmental quality standards for surface water (GB3838-2002), the water quality in the river section investigated can attain to the III water standards except total nitrogen. Further analysis indicated that there were no significant spatial differences in these parameters of water quality, but the sampling date had a significant effect. The temporal variation of water quality can be related to the discharge of Gezhouba Dam and moreover be affected by the reservoir regulation. During the discharge, the discharge increased the concentration of total phosphorus and then decreased the N:P ratio, which helps to the occurrence of algae blooms. The high consternation of phosphorus and the low N:P ratio show that the water body can be in the process of eutrophication during the discharge of Gezhouba Dam. In fact, Chl.a had begun to rise in the same period.
2008 年 12 月至 2009 年 11 月，对长江葛洲坝下游 70 公里河段的水质进行了调查。
共选择了 12 个站点。监测了包括总磷、总氮、叶绿素 a（Chl.a）、亚硝酸盐、硝酸盐、氨、水温、DO 和 pH 在内的 9 项水质参数，几乎每月监测一次。采用多元统计技术（聚类分析）和非参数方法（Kruskal-Wallis 检验和 Spearman 秩相关）评价水质数据集的时空变化。
根据中国地表水环境质量标准（GB3838-2002），调查河段的水质除总氮外，均可达到 III 类水标准。进一步分析表明，这些水质参数没有明显的空间差异，但采样日期有显著影响。水质的时间变化与葛洲坝大坝的放水有关，此外还受到水库调节的影响。放水时，总磷浓度增加，然后降低 N:P 比，有利于藻类大量繁殖。高磷含量和低 N:P 比表明，在葛洲坝放水期间，水体可能处于富营养化过程中。事实上，Chl.a 同期已开始上升。
