Influences of environmental governance project on spatial distribution of phosphorus in Lihu Lake

In order to evaluate the impact of the water environment governance project on the water quality in Lihu Lake,this paper studied on the spatial distribution of phosphorus and its influencing factors by an investigation in the Lihu Lake in April,2012.The results showed that the TP contents in the water ranged from 0.03 to 0.31mg/L with the mean value of 0.06 mg/L,and increased from the west to the east.At the same time,TP in the estuaries was higher than that in the lake.The spatial distribution of TP in the sediments was similar to that in the water.The TP in the sediments in the lake ranged from 321.77 to 1062.08mg/kg with the mean value of 593.75mg/kg,the TP in the estuaries ranged from 523.38 to 1396.39 mg/kg with the mean value of 784.51mg/kg.The long-term monitoring data of water showed that the water quality had been substantially improved by a series of water treatment projects,the annual average of TP in water fell from 0.18mg/L down to 0.06mg/L after governance project.However,due to the internal loading of phosphorus the eutrophication is still the mean problems we are facing.Furthermore,the correlation analysis indicated that the diffusion flux of phosphorus was positively correlated with the TP and the exchangeable phosphorus in the sediments.