梁子湖水系湖泊营养状况的综合评价

Comprehensive Assessment on Trophic State of Lakes Liangzihu Water System

用综合营养状态指数(TSIc),对梁子湖水系的4个湖泊营养状况进行了综合评价,并对4个湖泊的8项主要水化学指标进行了主成分分析。结果表明,洋澜湖、严家湖均呈富营养状态,武四湖、红莲湖分别呈中富营养及中营养状态,磷、硅对第1主成分贡献最大,氮对第2主成分贡献最大,4个湖泊的水质受水中磷含量影响最大。此外,4个湖泊中浮游植物、原生动物数量和生物量与TSI_C呈高度一致性。作者认为,对湖泊进行营养状态评价时,既要选准评价因子,又要对水化学参数和生物参数进行综合评价。

Comprehensive assessment on trophic States has been conducted in four shallow lakes of Liangzihu water system. By means of comprehensive trophic state index (TSIC) in which chlorophyll a (chla), water transparency (SD), total phosphorus (TP)and total nitrogen (TN) were used as evaluation factors, the qualitative evaluation for trophic states of four lakes were obtained. The principal components analvsis (PCA) of 8 water-chemical variables in four lakes were car-ried out. The results showed that PO4-P, TPand SiO2 were the main contributors to the first principal components, NO3-N, TN dominated the second principal components. Phosphorus content played the most im-portant role in determining water quality of four lakes. In addition, density, biomass of phytoplankton and protozoa were strongly correlated with comprehensive trophic states index. The case study suggested that the selection of evaluation factors and comprehensive analysis for water-chemical variables or hydrobios parameters should be considered in evaluating trophic states of lakes.