The Analysis Of City Non-point Source Pollution Load Under The Designed Storm

Under the active control of the point source pollution of urban area, the influence of non-point source pollution to the city water environment is more and more prominent. This paper takes the city non-point source pollution load as the research object, and consults the domestic and foreign research experience of the quantitative computation of the city non-point source pollution load. Then the paper compared the city non-point source pollution load models which are used widely at present. Combined the characteristic of the city non-point source pollution in Hangu of Tianjin, the Storm Water Management Model (SWMM) is finally chosen to be the research model, and the paper discussed the availability of the model when it is used on the study area. Then the paper analyzed the SWMM model on how to apply to the computation of the city non-point source pollution load. The paper studied the theories and the parameters of runoff model, pollution buildup and washoff model and transport model which are 3 sub models of the SWMM model, and determined the parameters on the base of actual material and the correlations research model parameters in domestic and foreign. Then according to the characteristic of the terrain, the draining water district, and the water collection of the study area, the paper established the non-point source pollution load model of Hangu city.At last, the paper designed some storm by"the storm formula of Tianjin"and"Chicago rain style formula", and used the non-point source pollution load model of Hangu city to simulate TSS, COD, TN, TP. From"same rain style different rain frequency","different rain style same rain frequency"two aspects, the paper simulated the production process and the load of the non-point source pollution. Meanwhile, the non-point source pollution load was simulated and compared under different non-point source pollution control measures.