基于层次聚类分析和水质标识指数的黄河兰州段水质评价研究

Water quality assessment of the Lanzhou reach of the Yellow River based on hierarchical cluster analysis and water quality identification index

为了解黄河兰州段的水质特征,选取新城桥、包兰桥、什川桥和青城桥4个监测断面,通过方差分析对2015—2019年4个断面240个水环境监测数据开展了显著差异性检验,并利用层次聚类分析将其分成9组。采用水质标识指数方法分别对各组样本均值进行水质评价,并将评价结果一一对应到各组水质样本点,为黄河兰州段水环境管理提供数据支撑。结果表明:黄河干流兰州段的水质状况良好,综合水质类别均为Ⅱ类。时间上,2015—2019年水质状况呈转好趋势;空间上,从上游到下游综合水质状况呈变差趋势。

In order to understand the characteristics of water quality in the Lanzhou section of the Yellow River,four monitoring sections,Xincheng Bridge,Baolan Bridge,Shichuan Bridge and Qingcheng Bridge,were selected to carry out significant difference tests on 240 water environment monitoring data from the four sections during 2015—2019 through variance analysis,and were divided into 9 groups by hierarchical cluster analysis.Secondly,the water quality index method was used to evaluate the mean values of each group of samples,and the evaluation results were corresponding to each group of water quality sample points,providing data support for water environment management in Lanzhou section of the Yellow River.The results show that the water quality of Lanzhou section of Yellow River is good,and the comprehensive water quality is class Ⅱ.From 2015 to 2019,the water quality showed a trend of improvement.Spatially,the comprehensive water quality from upstream to downstream is deteriorating.