Spatial Distribution and Evaluation of Nitrogen and Phosphorus in Upstream Rivers in Miyun Reservoir

The aim of study is to get main pollutants and spatial distribution in the upstream rivers in Miyun Reservoir, Beijing.210water samples were collected from fourteen river sections in every month in 2012to study spatial distribution of nitrogen and phosphorus.The results showed the same orders of the content of TN,TP,NO3-N and NH3-N were Chao RiverQingshui RiverBai River.The average measured concentration of TN,TP,NO3-N and NH3-N of Chao River were 4.63,0.024,4.41and 0.17mg/L,separately.The spatial distribution of concentration of TN,NO3-N,NH3-N were gradually decreased from upstream to the sections near the reservoir in Chao River,and maybe associated with the water conservancy project,the river self-purification and dilution.According to the national environmental water quality standards,the concentration of NH3-N,TP of three rivers were classified to level II,but TN exceed the quality standard of level V,also,the concentration of TN of thirteen river sections exceeded the standard of level V(2.0mg/L).Single contamination index method applied to evaluate water quality on the annual average TN,TP and NH3-N,it showed that TP and NH3-N classified into no pollution,but TN being heavy pollution indicating that the Nitrogen pollution cannot be ignored in upstream rivers to Miyun reservoir.