Non-Point Source Pollution Monitoring and its Loads Estimation Study on Surface Water Environment in Beijing

Non-point source pollution of surface water environment in Beijing was monitored and its loads estimation was studied.Monitoring results: natural rainfall was polluted on NH3-N and TN;organic pollution of storm runoff was very serious in urban typical underlying surface: TN and NH3-N was most serious in roof runoff;COD and TP were most serious in road runoff.Runoff of underlying surface cause sharper flush on deposit so that its water quality was more polluted when it enter sewer pipe system.Non-point source pollution was also serious in agricultural typical river basin.For pollution loads estimation,SWMM storm runoff model was used for urban non-point source;improved export coefficient model was used for agriculture non-point source.Estimate results: urban runoff mainly comes from wet deposition,runoff of roof and road;agricultural runoff mainly comes from farming land and forest land.The discharge amount in Beijing,either point source or non-point source is almost 50%.It provided scientific basis for reduction of discharge amount.