中文摘要：

在西藏尼洋河流域布设13个代表性采样点采集水样,通过现场测试水样的PH 值、电导率等指标和实验室分 析水样中18种元素含量,并运用综合指数评价法和Pearson相关性分析法对尼洋河水环境质量状况进行评价.结果表明： 尼洋河水样的pH值为8.10-8.80,呈碱性至弱碱性;元素含量基本达到《地表水环境质量标准》（ GB 3838 -2002） I 类标 准要求;除2、3号采样点重金属元素WQI在1-2之间外,其余11个采样点的WQI均 〈 1,表明尼洋河水环境质量良好,尚 未受到重金属明显影响.

英文摘要：

The water samples were collected from 13 representative sampling sites in Nyang River Basin in Tibet. The pH value and conductivity of the samples were measured and the contents of 18 kinds of elements in the water samples were analyzed. The comprehensive index method and Pearson correlation analysis method were used to evaluate the environmental quality of Nanyang River. The results showed that the pH value of Nyang Riv-er was 8. 10 ？8. 80,which was alkaline to weakly alkaline. The element concentration basically met the demand of ＂ Surface Water Environmental Quality Standard＂（ GB 3838 -2002） . Except for 2 and 3 sampling points, the WQI of the heavy metal element was between 1 and 2 , the remaining 11 sampling points WQI 〈 1 , which indi-cates that the water quality of the Nyang River is good and has not been affected by heavy metals.