为探明银川阅海湖水生生态系统健康状况，在2015年一2017年冬(1月)、春(4月)、夏(7月)、秋(10月)对阅 海湖水生态和水环境因子进行采样，通过主成分分析法筛选出叶绿素(China)、综合营养状态指数(TLI(∑))、浮游植物生物量(D)、底栖动物Shannon-Wiener指数(H＇底栖动物)、水生植物Shannon-Wiener指数(H＇水生植物)、高镒酸盐指数 (COD Mn)、总氮(TN)、氨氮(NH3-N)、总磷(TP)等9个因子构成阅海湖水生生态系统健康评价指标体系，运用主成分法确定了指标权重，运用灰关联法对水生生态系统健康等级进行评价。结果表明，阅海湖2015-2017年春季、夏季和秋季水生生态系统健康评价等级均为亚健康，冬季均为健康状态。氮磷营养盐超标是导致阅海湖2015-2017 年处于亚健康的主要原因。

The water ecological and water environmental factors were sampled to ascertain the health status of the aquatic ecosystem of Yuehai Lake in YinChuan in winter (January), spring (April), summer (July) and autumn (October) from 2015 to 2017. Nine factors such as chlorophyll (China) , comprehensive nutritional status index (TLI(∑)) , phytoplankton biomass (D), benthic Shannon-Wiener index(H＇Aquatic plant) ,and aquatic plant Shannon-Wiener index(H＇Benthic) , permanganate index (CODmh), total nitrogen (TN), ammonia nitrogen (NH3-N), total phosphorus (TP) were selected to establish evaluation index system u- sing principal component analysis (PCA) for the health assessment of the aquatic ecosystem in Yuehai Lake. The PCA method was used to determine the weight of the index, while the gray relational method was used to evaluate the health level of the a- quatic ecosystem. The results showed that the health assessment grades of the aquatic ecosystems in the spring, summer and autumn were all sub-health from 2015-2017, whereas in winter, the status was healthy. The extreme level of nitrogen and phosphorus nutrients were the main cause of sub-health in Lake Yuehai from 2015-2017.

宁夏高等学校一流学科建设(水利工程XNXYLXK2017A03)