典型湖库叶绿素a含量测定及富营养化分析

Chlorophyll a Content Determination and Eutrophication Analysis of Typical Lakes and Reservoirs

水体富营养化是由自然因素和人为因素的共同作用造成的,其影响水体中营养盐的含量,导致淡水湖泊中氮、磷、钾等元素含量逐渐升高,从而使藻类植物过度增殖。叶绿素a含量是评价水体富营养化状态的重要指标之一。对我国典型大型湖库丹江口水库6个点位的地表水水体中叶绿素a含量进行了提取测定。利用综合营养状态指数法计算丹江口水库营养状态指数。结果表明,6个点位的地表水中叶绿素a浓度范围在1.17~4.31μg/L之间,综合营养状态指数在32.6~38.1之间,湖库营养状态等级总体上处于中营养状态,有进一步富营养化的风险。

The eutrophication of a water was caused by the combined action of natural and human factors,which affects the content of nutrients in the water,resulting in a gradual increase in the content of nitrogen,phosphorus,potassium and other elements in freshwater lakes,thus causing the process of excessive proliferation of algae.Chlorophyll-a con⁃tent is one of the important indicators to evaluate the eutrophication status of water.In this paper,the content of chloro⁃phyll-a in the surface water of Danjiangkou Reservoir,a typical large lake and reservoir in China,was extracted and determined at 6 sites.The comprehensive nutritional status index method is used to calculate the nutritional status index of Danjiangkou Reservoir.The results show that the concentration range of chlorophyll-a in surface water at 6 sites is 1.17~4.31μg/L,the comprehensive trophic status index is between 32.6~38.1,and the trophic status level of lakes and reservoirs is generally in the middle trophic status,with the risk of further eutrophication.