基于主成分分析及水质标识指数法的黄河托克托段水质评价

Evaluation of Water Quality of Tokto Section in Yellow River Based on Principal Component Analysis and Water Quality Identification Index

[目的]分析黄河托克托河段水污染特征,合理选择水质评价指标,从而实现对黄河托克托段水质评价。[方法]以黄河托克托段干流2017年4—8月9个水质采样断面逐月连续水质监测数据为基础,利用多元统计法对水质样本进行主成分因子分析,构建水质评价指标体系,应用综合水质指数法对该河段水质进行评价。[结果](1)黄河托克托段水质状况整体为Ⅳ类水,该河段段主要污染因子为TN,TP,COD,属于有机型及富营养化污染;(2)时空分布上从上游到下游水质逐渐变好,支流汇入口大黑河断面由于受汛期大黑河超标污染物排入水质变差,采样期间8月水质状况最差,其次是4月,5—7月水质相对较好。[结论]基于主成分因子分析和综合水质标识指数法的水质评价方法不仅可以准确客观地反映水质特征,同时可对不同断面水质进行比较。黄河托克托段水质状况较差(整体Ⅳ类),属于有机型及富营养化污染。

[Objective]Characteristics of water pollution in the Tokto section of the Yellow River and selection of water quality evaluation index is of great importance for assessing the the water quality in the Tokto section.[Methods]Based on the data of 9 sampling sections in the Tokto section from April to August in 2017,we comprehensively evaluated the water quality by establishing the evaluation index system using principal components analysis.[Results]①The water quality in the Tokto section could be classified into classⅣ,and the main pollution factors are total nitrogen,total phosphors,chemical oxygen demand,belonging to organic type and eutrophication pollution.②The water quality from upstream to downstream was becoming better The water quality of the Heihe River at the entrance of tributary became worse due to the excessive pollutant discharge into Heihe River during flood season.The water quality was the worst in August and April,and was better from May to July.[Conclusion]The water quality evaluation method based on the principal component analysis and the synthetic water quality index can not only accurately reflect the water quality,but also compare the water quality of different sections.The water quality in Tokto section of the Yellow River is poor(the whole classⅣ),which belongs to organic pollution and eutrophication.