宁夏沙湖水体富营养化分析与评价

Evaluation and Analysis on Trophic Level in Shahu Lake

于2008年4月至2009年1月对宁夏沙湖水质进行调查,分析了透明度、叶绿素a、高锰酸盐指数、总氮、总磷、浮游植物等水质指标季节变化规律,采用非生物因子、综合营养状态指数(TLI)与浮游植物密度、生物量、种类组成、多样性指数等对其营养水平现状进行分析和评价。结果表明,沙湖水体已达到富营养化状态。营养状态指数评价结果表明夏季TLI最高,为中度富营养;秋季、春季为轻度富营养。Shannon-Wiener指数(H)、Margalef指数(D)评价表明水体均受到不同程度的污染,夏季污染程度最高。

Water quality in Shahu Lake was evaluated based on some main water parameters as transparency, chlorophyll a, CODMn, TN, TP and phytoplankton investigated from April 2008 to January 2009. Comprehensive abiotic environmental factor, trophic state indices TLI （Σ）, Shannon-Wiener index H,Margalef index D and species composition,density,biomass, dominant specie of phytoplankton were used to value the water trophic status. The trophic level of Shahu Lake was found under eutrophication. The evaluation result of TLI（Σ） indicated the water quality was at middle eutropher in summer and light eutropher in autumn and spring season. The evaluation results based on Shannon-Wiener index and Margalef index indicated that the water in Shahu Lake was polluted.