Non-point Source Pollution Is To Quantify The Important Factors In The Model

Aquatic environment pollution caused by non-point source is becoming more and more serious, which raises worldwide scholars' attention. Hence, studying on the origin, disadvantage, transport and transformation rules of the non-point pollution, estimating correctly the non-point pollutant load turn into the crucial problem on prevention and cure of water pollution.Based on the mechanism research and the literatures home and abroad on the non-point source, the influencing factors of non-point pollution estimated model are chosen as studying object in the thesis. The study focuses on the relationship between the C factor value and the soil erosion, basis of value deciding , estimated method, restricted ingredient of the cover-management factor related to soil erosion of the USLE USA. Taking into account of regional characteristic of C factor, manual rainfall and sampling runoff using simulation experiment in minitype region are applied, and the C value is calculated approximately and established for the first time. Then both the experimental C value and the experienced C value are applied to calculate the non-point pollution load simultaneously in the Erlong lake, Jilin province. The result are different. After comparing with the data which is calculated by the mud and sand in reverse from the Hydrology Ministry and Soil & Water Preservation Institute, the conclusions are as follows:1) Comparing the experimental C value in the manual rainfall runoff simulation experiment with the experienced C value, the experimental C values are less than the experienced C values except in the slope woodland; the experimental C values are mostly identical in dry land, woodland, low-cover grassland with the data of other areas in our nation, while the C values in bush and high-cover grassland are less.2) Calculating the soil erosion modulus(A) using the two C values, the A values in dry land, township resident land, the land used for industry,traffic,construction, and country resident land are bigger, and the A values in the other landuse types are less.3) The difference of the volume of the soil loss using these two C values is obvious. The volume of the soil loss using the experienced C values is bigger than using the experimental C value mostly beyond some of exceptional.4) In the Erlong lake region, the problem of erosion of soil and loss of N, P is serious in the slope dry land, so it is the source of soil erosion and pollutant release, and it should be controlled and managed.5) Comparing the total volume of soil loss using the C value calculated by the mud and sand in reverse from the Hydrology Ministry and Soil & Water Preservation Institute, the two losses are identical mostly, especially in the woodland, dry land. The experimental C factor value proves to be of high reliability and practicability. It can provide scientific basis and practical estimated method for controlling and managing soil erosion and nutrition elements loss in Jilin province.