【摘要】 1990—1991年对五里湖的调查表明,该湖已发展到富营养一重富营养阶段。湖水中TN、TP、Chla、BOD₅和COD_cr的平均含量分别达到2.25mg/L、111μg/L、31.8μg/L、4.9mg/L和17.5mg/L,平均透明度只有0.51 m。表层底泥中氮、磷和有机质的含量分别高达0.181％,0.071％和2.51％,成为巨大的内营养源;而外源营养物则主要来自梁溪河和五里湖北岸各支流。以硅藻为主的浮游藻类年生产力约为5200 t/km²（鲜藻）,是该湖有机污染的主要来源。治理应从污染源控制入手,在东北端河道上建闸拦污,在北岸建立环湖集污河道;废止航运和局部清淤以削减内污染源;在沿岸带恢复水生植被以固持底泥;在东部湖区建立拥有水生植被的水源保护区以改善中桥水厂的水源水质。更多还原

【Abstract】 According to the surveys from 1990 to 1991, the Wuli Lake entered a eutrophic period, which seriously affected drinking water supply and entertainment. The mean concentration of TN, TP, ChLa, BOD and COD in the lake water were 2. 25 mg/L , 111 μg/L, 31. 8 μg/L, 4. 9 mg O2/L and 17. 5 mg O2/L respectively. The water had a mean SD of only 0. 51 m. The mud in the bottom contained 0. 18% of nitrogen, 0. 071% of phosphorous and 2. 51 % of organic matter. The phytoplankton dominated by diatom gave an annual productivity of 52 t/hm2 (fresh algae), the main source of organic matter in the lake. To restore this lake, the pollutant input should be cut off by building sluice gates on its rivers and setting up waste water dispersing system around the lake. The mud should be removed from the lake bottom and water transport forbidden. Re-establishing aquatic vegetation in the littoral zone would effectively promote the restoration of water quality and environment. It may be a good way to improve the drinking water quality in a short time by setting up a water source protective area in the eastern part of the lake and recovering aquatic vegetation in it.更多还原