Investigation And Study On Laws Of The Three Gorges Reservoir Area Agricultural Non-Point Source Pollution

The Three Gorges Project building, produces the gigantic positive effect toenvironmental protection and the agriculture. But, After Three Gorges Projectestablishes storing water, a series of changes happened in the Reservoir Areaecological environment. Agricultural non-point source pollution, especially nitrogenand phosphorus nutrient become the Three Gorges reservoir area's main water sourceof pollution serious impact on the region where the quality and safety of water and thesustainable development of agriculture. Study on the Three Gorges reservoir areaagricultural non-point source pollution have importance to regional pollution controlscientific management to provide a scientific basis and propose targeted treatment.In this paper, the cultivation of natural rainfall in the district under monitoring,research farmland on the slopes of the Three Gorges reservoir area of agriculturalnon-point source pollution of nitrogen, Phosphorus nutrition and the elements of therun off of law; Meanwhile in the Three Gorges reservoir area several main agriculturalnon-point source pollution survey right which nitrogen, phosphorus inflow watervolume estimate. The results showed:1. Rainfall of nitrogen and phosphorus are associated with the run off, while beingattached to ground vegetation, anthropogenic interference; slope in a certain range andnitrogen, phosphorus loss there is a positive correlation between the Three Gorgesreservoir area of nitrogen, Phosphorus Loss 25°slope＞15°slope＞5°slope, the ThreeGorges reservoir area critical gradient of more than 25°; Other factors in the samecircumstances, soil types and nitrogen, phosphorus loss to a certain extent; fertilizerapplication and the loss exists between the linear relationship.2. The Reservoir Area nitrogen phosphorus general running off of measure ThreeGorges in 2005 for 27616.76 tons, that TN among them flow into wave amounts beingamounts take up general running off 24479.94 tons. 88.6%; TP flows into waveamounts being 3136.82 tons, general running off amounts's 11.4%. From the sourcecontaminating a source looking at livestock poultry excrement for the nitrogen,phosphorus nutrition element main part run off, run off for all quantity accounting forthat general running off expects that 53.3% 14724.22 tons; Be that the nitrogenphosphorus runs off in the chemical fertilizer secondly, run off all quantity is 9937.9tons, general running off amounts's 36%; The running off that running off is short mostin the amounts for the pesticide middle organic nitrogen, the organic phosphorus,takes up all quantity's only 0.2%. 3. Amounts pollution sources come from nitrogen running off, in 2005 nitrogenrunning off is maximal in Three Gorges Reservoir Area pollution source for thenitrogen runs off, accounts for 56% of all quantity in livestock poultry guano urine,account for 34% secondly for the chemical fertilizer nitrogen runs off. the domesticsewage and human excrement nitrogen running off are account for 9.9%, but thefewest for the pesticide nitrogen runs off accounting for 0.1% only. Amounts pollutionsources come from phosphorus running off, in 2005 phosphorus running off ismaximal in Three Gorges Reservoir Area pollution source for the phosphorus runs off,accounts for 53% of all quantity in the chemical fertilizer, account for 29% secondlyfor the livestock bird guano urine phosphorus runs off, the domestic sewage andhuman excrement phosphorus running off are account for 17%, but the fewest for thepesticide phosphorus runs off accounting for 1% only.4. Three Gorges Reservoir Area in 2005 every area county nitrogen phosphorusentrance wave all quantity difference is bigger, enter wave nitrogen phosphorusamounts the most three area counties among them being 5824.04 tons of Feng DuCounty respectively, account for 21.1% of all quantity; 3500.59 tons of Yun YangCounty, account for 12.7% of all quantity; Ba Nan county accounts for 11.1% of allquantity 3061.71 tons. The Three Gorges Reservoir Area nitrogen phosphorus enterswave amounts in 2005 exceeding average horizontal 6 counties city middle, generalnitrogen amounts are all bigger, to exceed all quantity in general 80%.5. Judging from nitrogen phosphorus element source, can classify those 6discharge amounts big counties for several kinds types: Feng Du County is a livestockpoultry guano urine leading factor type; Yun Yang County, Banan district, Feng JieCounty are livestock poultry guano urine, chemical fertilizer leading factor type;Zigui, Fu Ling are a chemical fertilizer, livestock poultry guano urine leading factortype.6. Agricultural non-point source pollution control study to take three maincategories of methods for control and management. First, the adoption of economic,legal, educational tools; second are taken to control the source means;Third is taken onthe relocation process pollution control means.