Application of Principal Component Analysis on Water Quality Assessment of Caohai Lake in Guizhou

The environmental pollution of Caohai Lake has become more serious recently,which has attracted extensive attention.Using the principal component analysis,seven indexes of water quality including CODMn,BOD5,NH3-N,COD,TP,TN and DO observed in twenty-three monitoring data of sampling point in Caohai Lake were analyzed.This paper made a quantitative estimate of the water contamination degree of Caohai Lake.Results showed that the main pollution factors of Caohai Lake were CODMn,BOD5,TN,TP and COD.The pollution difference was obvious in the Caohai Lake with a fact that the upstream was less pollutant than the downstream.The pollution of Caohai Lake was exogenous.The major pollutants of Caohai Lake were life sewage from residents in Weining county and the agriculture pollution sources surrounding the lake.Therefore,reduction of the living pollution and scientific application of pesticides and chemical fertilizer are very important ways to improve the water quality of Caohai Lake.