Abstract:
Three hundred and sixty water samples were collected from the Dongting Lake from January to December in 2011. The physio-chemical factors of water samples including pH, DO, BOD
5, TP, COD
Mn, COD
Cr, NH
3-N, TN, fecal coliform and Chla were measured and analyzed by methods of the principal component analysis. The results showed that DO, BOD
5, TP, COD
Mn, COD
Cr, TN, NH
3-N and Chla were the main impact factors of the water quality at Yugongmiao and Lujiao. The other sectoins, Nanzui, Muping Lake, Heling Lake and Wanzi Lake were greatly influenced by the concentration of TP, while Xiaohezui was mainly influenced by concentrations of TP, BOD
5 and Chla. The East-Dongting Lake was mainly influenced by concentrations of BOD
5 and Chla. In contrast, Yueyanglou and Dongting Lake outlet were much influenced by concentrations of DO, COD
Mn, COD
Cr, NH
3-N and TN. Results with the scores of integrative principal component showed that the order of pollution degree in the sampling sections was as follows:Yugongmiao > Lujiao > East-Dongting Lake > Yueyanglou > Dongting Lake outlet > Nanzui > Hengling Lake > Muping Lake > Xiaohezui > Wanzi Lake.