关键词: 长江流域, 大型水库, 富营养化, 成因

Abstract: 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.

Key words: the Yangtze Basin, large reservoir, eutrophication, cause