主成分分析法在高州水库水质评价中的应用

Application of Principle Component Analysis Method in Water Quality Assessment of Gaozhou Reservoir

根据主成分分析法能够从众多因子中筛选出主要成分,且在保证原始数据信息损失最小的情况下,利用SPSS软件对数据结构进行简化,以少数综合变量取代原有的多个变量,对高州水库汇水流域内主要河流进行水环境质量综合评价,并对各监测断面的水质优劣程度进行了排序。从原始数据中提取占总方差96.425%的3个主成分以反映研究区水质的整体情况,结果表明:流域内水环境质量总体较差,以入库河流上游区域的农业、生活引起的非点源有机污染为主,库区内存在一定程度的富营养化趋势,且在水库自身水动力条件的作用下库区水质优于入库河流。在空间分布上,由于石骨水库库心断面受外源污染影响较小,其水质优于供水口;而入库河流中良德水库黄塘水入口断面水质污染较轻,石骨水库曹江入口断面次之,良德水库大井河入口断面的水质最差。此外,通过对流域水环境质量进行分级综合评价,进一步得出高州水库入库河流是库区污染的主要来源。

Based on Principal component analysis （ PCA） , the main components can be extracted from many factors, and guarantee minimum loss of original data information , using SPSS software to simplify the data structure , replace the original multiple variables with a few comprehensive variables . The water environment quality of main rivers of Gaozhou Reservoir catchment basin was evaluated, and the water quality of each monitoring section was ranked. The three principal components which account for 96. 425% of the total variance were extracted from the original data to reflect the whole situation of water quality in the studied area. The results showed that the overall water quality of the basin is poor, the pollution come from inflow tributaries, mainly organic nonpoint source caused by agriculture and life. The reservoir has certain degree of eutrophication, and due to the hydrodynamic conditions in the reservoir, the water quality in the reservoir is better than that of inflow rivers. In the spatial distribution, because of the middle section of Shigu reservoir was less influenced by exogenous pollution, the water quality in the middle of the reservoir is better than that of the water inlet. Among the inflow rivers, the water pollution inLiangde Reservoir Huangtang river pond water inlet section is light, followed by Shigu Reservoir Caojiang river inlet section, and water quality of Liangde Reservoir Dajing river inlet is worst. Furthermore, through comprehensive classification evaluation of river basin water environment quality, get the conclusion that inflow river was the main pollution source of Gaozhou reservoir.