Assessment And Countermeasures Of Agricultural Non-point Source Pollution In Three Gorges Reservoir Area

After the Three Gorges Reservoir taken into use, the stream in Changjiang river slows down, and agricultural non-point source(NPS) pollution threatens the safety of surface water in that area. Thus an knowledge of the condition and characters of agricultural NPS pollution has both academic and realistic meaning to control agricultural NPS pollution, improve the ecological environment and realize the harmonious development of economy, environmental and society.The control technology of NPS pollution in the world and its research progress were summarized in this thesis. Aiming at catchment management, a detailed classified investigation of agricultural NPS pollution in Three Gorges Reservoir area was carried on for the first time, and an assessment to all kind of pollution sources was done by Equal Standard Pollution Index Method and Equal Standard Pollution Load Method. In addition, the management and control planning of NPS pollution was proposed based on above investigation and assessment.As the research results show, the Equivalent Standard Pollution Loading Rate of COD, TN and TP, which means surface water pollution degree from pollutants, was separately 5.76%, 52.18% and 42.06%, and the main pollutants were TN and TP. The Equivalent Standard Pollution Loading Rate of livestock pollution, living pollution, fertilizer pollution and fishery pollution was separately 41.51%, 21.05%, 33.21% and 4.23%, and the main pollution sources were livestock pollution source, fertilizer pollution source and living pollution source. The Equal Standard Pollution Index in Chongqing downtown district, Changshou district, Banan district, Yubei district, Zhongxian county and Jiangjin city were evidently higher than others.The agricultural NPS pollution in Three Gorges Reservoir was classified into three kind of types. Firstly, Combined Pollution style I in Banan district and Changshou district, in which style livestock pollution, living pollution, fertilizer pollution and fishery pollution impact averagely and had similar percent. Secondly, Combined Pollution style II in Chongqing downtown district, Jiangjin city, Yubei district, Fuling district, Zhongxian...