基于主成分及聚类分析的内陆河流水污染特征研究

Water Pollution Characteristics of Inland Rivers Based on Principal Components and Cluster Analysis

采用主成分分析法对西北内陆某城市河段的主要特征污染指标进行了评价,针对特征污染指标运用空间聚类分析法,研究各关键指标的空间分布特征,对特征指标的关键控制点位的时间分布进行了探讨。研究结果表明,秋季研究河段受总磷、有机污染的影响较大,夏季受氮素污染的影响较大,与农田、农村、生活排水等有较大的关系。秋季河段上游TN、TP、CODcr的污染程度均最高,河段中下游段则受上游城镇生活、工农业等污染排放的影响较显著。夏季上述三个指标受入河污染源的影响较小,受各类面源污染的影响较大,整体表现为河段北面整体污染高于南面,上游水质好于下游水质。河段上下游区域夏季TN、TP、CODcr均高于秋季,整体表现为夏季水质总体劣于秋季,河段中部TN、TP在夏季浓度与秋季差别不大,没有显著的一致的好劣趋势。

this paper uses principal component analysis method to evaluate the main characteristic pollution indexes of a river reach in a city in the northwest inland,and uses spatial cluster analysis method to analyze the characteristic pollution indexes. The spatial distribution characteristics of each key index are studied,and the time distribution of key control points of the characteristic index is discussed. The study results show that the river reach studied is greatly affected by total phosphorus and organic pollution in autumn,while by nitrogen pollution in summer,which is closely related to farmland,rural areas,and domestic drainage. In autumn,the river reach has the highest pollution levels of TN,TP and CODcr in the upper reaches,and it is significantly affected by urban domestic pollution,industrial and agricultural pollution emissions in the middle and lower reaches. In summer,the above three indicators are less affected by pollution sources into the river,and more affected by all kinds of non-point source pollution,which as a whole shows higher pollution in the north of the river reach than in the south,and better water quality in the upper reaches than in the lower reaches. TN,TP and CODcr in the upper and lower reaches of the river reach are all higher in summer than in autumn,which as a whole shows worse water quality in summer than in autumn. The concentrations of TN and TP in the middle reaches of the river reach in summer have little difference with those in autumn,and there is no remarkably consistent water quality trend.