蠡湖综合整治十年来水环境变化的研究

对蠡湖2002-2012年湖体水质、富营养化状况和浮游植物种群进行了研究.结果表明,经过十年蠡湖综合整治工程,蠡湖水环境有了显著改善.TN、TP、NH3-N、CODMn和Chl-a浓度分别下降85.2％、70.4％、96.2％、55.3％和81.6％;TLI由70.9降至52.0,水体由中度富营养好转为轻度富营养;浮游植物种群结构有所演变,近二年种群结构呈现明显季节性差异,夏季蓝藻中的微囊藻成优势种,约占整个水体藻类密度的90％以上.蠡湖水质显著改善的同时,藻类水华情况未得到本质好转,在适宜的水文气象条件下易发生藻类水华.建议提高水体透明度,增加水体流动性,为进一步改善蠡湖水环境,乃至改善湖河小流域水环境起积极作用.

The Study on Water environmental Improvement of Lihu Lake for 10 Years Comprehensive Treatment Projects

The water quality, eutrophication and phytoplankton species of Lihu Lake were studied in this paper from 2002 to 2012. The results showed that Lihu Lake water environment had improved significantly by the comprehensive treatment projects. The descend ranges of TN, TP, NH3 -N, CODM, and Chl -a concentration were about 85.296 , 70. 4% , 96. 2% , 55. 396 and 81. 696. TLI decreased from 70. 9 to 52. 0 and the water eutrophication level improved from moderate - eutrophication to light - eutrophication. The evolution of phytoplankton species was happened in 10 years. And it shows an obvious seasonal difference of phytoplankton community structure in the last 2 years. Microcystis is the dominant species in summer which is above 9096 of algal density. However, algal bloom situation did not turn to the better during the 10 years, and algal bloom will happen in appropriate hydrology -weather condition. Finally, it was suggested to improve water transparency and increase water flow in order to further improving water environment of Lihu lake or even the small lake - river basin.