Spatial Distribution Characteristics of Nitrogen,Phosphorus and Chlorophyll in Water from Nansihu Lake

The concentration and spatial distribution characteristics of nitrogen,phosphorus and chlorophyll a(Chla) in different zones from Nansihu Lake were studied.The results showed that values of primary water quality parameters in Nansihu Lake had a spatial heterogeneous distribution.The concentrations of total nitrogen(TN),total dissolved nitrogen(DTN),ammonium(NH+4-N),total phosphorus(TP),total dissolved phosphorus(DTP),and orthophosphate(PO3-4-P) in water from Nanyang Lake were significantly higher than those in other zones of Nansihu Lake,and the concentration of different forms of nitrogen and phosphorus between Dushanhu Lake,Zhaoyanghu Lake,and Weishanhu Lake had no significant difference.The trends of DTN and NH+4-N concentration with TN,and of DTP and PO3-4-P concentration with TP were totally fitted by the linear equations respectively.The spatial distribution of Chla concentration in water from Nansihu Lake was obviously different,and Chla concentration was the highest in Nanyanghu Lake,and the lowest in Weishanhu Lake.The Chla concentrations were significantly negatively logarithmic correlated with values of pH,and the ratio of total nitrogen and total phosphorus.However,remarkably positively logarithmic relationships were observed between the concentrations of Chla and TN,DTN,NH+4-N,TP,DTP,PO3-4-P,and chemical oxygen demand(COD).