| In order to analyze the variation of water quality, surface water was collected from ten sampling sites in Poyang Lake in Oct. 2010 and May 2011 respectively. The results indicated that the contents of COD, TN and TP have been subjected to eutrophication status in Lake Poyang. There were significant differences among physicochemical parameters. The contents of COD, TN, NH+4-N, NO-3-N and TN/TP in Oct. 2010 were significantly lower than those in May 2011 respectively. In contrast, the contents of TP and Chl-a were significantly higher in Oct. 2010 than May 2011. Besides, samples from Rao River Estuary have highest concentrations of COD, TN, TP, and the content of Chl-a in Nanjishan Region Estuary was significantly higher than other sampling sites. Principal component analysis revealed that water quality in Poyang Lake was mainly affected by dissolved oxygen, transmittance and conductivity. Accoding to the variation among sampling sites, water quality was affected less by nutrients of nitrogen and phosphorus in Hukou, the North and South regions of Poyang, Fu River Estuary and Sanjiangkou , while more in other sites. |
