长江流域大型水库富营养化特征及成因分析

在对长江流域27座大型水库营养状况调查评价的基础上，深入分析了大型水库富营养化的特征和成因。结果表明水库富营养化状况与水库类型、水库流域的位置和水库的功能存在着明显的关系，湖泊型水库富营养化程度高于河道型水库，以灌溉为主的水库富营养化程度高于以发电为主的水库；调查的14座河道型水库和13座湖泊型水库中，分别有21.4%的河道型水库和69.2%的湖泊型水库达到富营养化水平；以发电为主的水库30%已达到富营养标准，而以灌溉为主的水库中达到富营养的占53.8%。另外，水库的富营养化程度与水文情势的变化密切相关，通过水位或水滞留时间的调节，对营养物质、藻类组成和现存量进行调控，影响水库富营养化进程。最后，提出对水文情势的调控是控制水库富营养化的有效措施之一。

CAUSES AND CHARACTERISTICS OF THE EUTROPHICATION IN LARGE RESERVOIRS IN THE YANGTZE BASIN

Based on the investigation of 27 large reservoirs in Yangtze Basin, this paper dealed with the causes and characteristics of the eutrophication in these reservoirs. The results showed that the eutrophication is obviously related with the type and function of the reservoirs. The eutrophication level of lake-type reservoirs is higher than that of rive-type reservoirs; the eutrophication level of the reservoirs primarily for irrigation is higher than that of reservoirs for power generation. Among the 14 river-type reservoirs and 13 lake-type reservoirs investigated, 21.4% of the river-type reservoirs and 69.2% of the lake-type reservoirs are eutrophicated; 30% of the reservoirs for power generation are eutrophicated, while (53.8%) of those for irrigation. Besides, it is also indicated that the level of eutrophication has high relation with the hydrological regime. Through regulating water level or hydraulic retention time, the composition of nutrients and standing crop of algae can be adjusted, At last, the authors puts forward the viewpoint that adjusting the hydrological regime is one of the effective measures to control the eutrophication in reservoirs.