Total Amount Control On Non-point Pollution From The Watershed Of Miyun Reservoir

With the progress of environment management, people have realized that the objective of the water quality won't come true only with implement concentration control on pollution source. Implement total amount control on contamination discharge is necessary for pollution control. Total amount control ensures the maximum permission load on the objective or target and load allocation among pollution sources in reasonable orders. Pollution total control scenario is rational performed that it may avoid the phenomena of disjoint and conflict between the concentration discharge target and water environment quality objective.As an important water source, Miyun reservoir plays a crucial role in Beijing. The water quality of Miyun reservoir accords with the second class level of the surface water quality in China and is at the medium-eutrophication situation, which is mainly caused by the non-point source pollution (NPS) in the watershed .Therefore, it is important to study the total amount control including non-point source in the watershed.First, using the monitoring data during the years of 1999-2003 of water body of Miyun Reservoir, the load of phosphorus is estimated using Dillon model. The permission load and actual load of the study area are 3.58tons/a and 5.93 tons/a, respectively, so the load needing reduced is 2. 35 tons/a.Second, contributions of different pollution sources to total phosphorus contribution are determined. Total phosphorus from Sanitary sewage, air precipitation, agricultural chemical, livestock and poultry feding and soil erosion are confirmed 4.62 tons/a, 4.07 tons/a, 4.61 tons/a, 407.61 tons/a and 5.18 tons/a respectively, total 426.09 tons/a. Among them, livestock and poultry feding account for 95.66% of total amount to total contribution of phosphorus to cultivate, total phosphorus contribute proportion the poultry accounts for up to 70.09% in cultivating in livestock and poultry feding, and of different villages and towns total phosphorus contribution rate a heavy Fengjiayu accounts for 37.57%. Rely mainly on intensifying the livestock and poultry feding to cultivate mainly in cultivating in the livestock and poultry feding, concentrated livestock and poultry feding total phosphorus produced to cultivate only account for 12. 49% .Total phosphorus from agricultural chemical, livestock and poultry feding excrement and urine or sanitary sewage will enter the water body through different land use. This watershed is 10.57 tons/a with the output amount of the total phosphorus fromdifferent land use. Among them, total phosphorus output from the cultivated land is the highest, accounting for 52. 41%. Secondly the forest land and the urban land used, accounting for 19.02% and 17.88% respectively, total 89.31%. rivers and meadow produce is relatively small.Then, the pollution load allocation among some sources in the watershed of MiyunReservoir is estimated. The reduced amount from cultivated land, forest land , meadow ,urban and of rivers and canals are 2. 2tons/a, 0. 8 tons/a, 0. 3 tons/a, 0. 75 tons /a and 0. 15 tons/a respectively , total 4.19 tons/a.According to the evaluation of the pollution sources and calculation of the load of permission, the actual load of Miyun Reservoir still exceeds the load of allowing greatly. In order to improve the water quality further, the paper puts forward the suggestions on management measures to control of non-point sources in the watershed. To control from source is the main method. On one hand, the way of landuse should be adjusted, on the other hand, the cultivation of livestock and poultry feding should be strengthened and managed.