运用主成分分析法研究云南湖库水体中重金属分布

以云南省38个高原湖库为研究对象，测定了表层水体中Cu，Zn，Pb，Cr，Cd，As，Fe，Mn和Ni 9种重金属质量浓度. 运用主成分分析法对水体中的重金属分布情况和来源进行了分析. 结果表明:所调查的云南38个湖库水体中主要重金属的分布可由4个主成分来反映，其贡献率分别为F1(Zn，Mn，Cd)35.23%，F2(Pb，Ni)17.05%，F3(Fe，Cu)15.70%和F4(Cr，Fe)13.10%. 38个湖库表层水中均有多种不同质量浓度的重金属存在，在该调查时段，有8个湖库表层水体中部分重金属质量浓度超过《国家地表水环境质量标准》(GB3838—2002)Ⅲ类水标准限值，水质不符合饮用水标准；而其他30个湖库表层水体中重金属质量浓度符合Ⅱ类水标准. 在部分湖库中ρ(Fe)，ρ(Mn)，ρ(Zn)，ρ(Cd)和ρ(Ni)超过Ⅲ类水标准限值，在表层水体中ρ(As)，ρ(Cu)，ρ(Cr)和ρ(Pb)较低，符合饮用水的标准要求. 主成分分析法能够较好地分析云南38个湖库水体中重金属的分布情况. 

Application of Principal Component Analysis to the Distributions of Heavy Metals in the Water of Lakes and Reservoirs in Yunnan Province

Mass concentrations of heavy metals (Cu, Zn, Pb, Cr, Cd, As, Fe, Mn and Ni) in surface water of 38 lakes and reservoirs in Yunnan Province were determined. Principal Component Analysis (PCA) was applied to analyze the distributions and sources of heavy metals in the surface water. Results showed that the first four principal factors F1 (Zn, Mn, Cd), F2 (Pb, Ni), F3 (Fe, Cu) and F4 (Cr, Fe) could account for the principal distributions of heavy metals in the surface water. The percents of the total variance were 35.23%, 17.05%, 15.70% and 13.10% respectively. Pollution levels of heavy metals in the surface water were estimated according to Environmental Quality Standards for Surface Water (GB3838- 2002). The results revealed that there were different species and mass concentrations of heavy metals in the surface water of the 38 lakes and reservoirs. In the investigation period, mass concentrations of some heavy metals in the surface water of eight lakes or reservoirs exceeded the third class of Environmental Quality Standards for Surface Water and the recommended standard for drinking water, while mass concentrations of heavy metals in the surface water of the other 30 lakes or reservoirs accorded with the second class Environmental Quality Standards for Surface Water. The surface water was partly suffering from Zn, Cd, Fe, Mn and Ni contamination. The mass concentrations of As, Cu, Cr and Pb were below the acceptable standards for drinking water. The information of PCA effectively revealed the distributions of heavy metals in the 38 lakes and reservoirs.