The Situation Of Soil And Water Loss In Non-point Pollution In Jiangning District And Effect Of Vegetation On The Water Environment

This thesis analysis the dynamic changes of non-point source pollution of soil erosioninJiangning district. Study the pattern of N&P elements in non-point source pollution inmesoscale, and put the region of Qinhuai River (in Jiangning district) and Copper Mountainwoodland as mainly research objects. Study about aquatic plants for water purification efficiencyand yypical forest’s impacts on water quality.Through these topics, the result shows that:(1)Through the analysis of soil erosion of ten years’ non-point source pollution in Jiangningdistrict, TN&TP’s non-point source contamination are at middle level, ammonia nitrogen ismildly pollution, and available phosphorus is micro contamination.In the4types of contaminants,ammonia nitrogen and available phosphorus are basicly happened in the areas of mild soil andwater loss at non-point source pollution.(2)At the Qin Huai River (Jiang Ning) River area, the overall eutrophication evaluation isheavy eutrophication, and the ordering of eutrophication levels in the section is D>C>B>E>A.The sort of different environmental indicators nutrition is CODcr>TP>TN>BOD5, the sort ofeutrophication’s level in each season is spring> autumn> winter> summer;(3)The riparian communities of aquatic plant on the river bank are basicly composed by threecommunities; they are reeds, water peanuts and Eichhornia crassipes. It have a simplecommunity structure, and low level species diversity, and owns25species of aquatic plants.Theratio of natural aquatic plant remove TN&TP could reach up to39%, and66%, it have a clearlyremove effect. However, it has not a strong remove effect when it comes to CODcrand BOD5.The sord of Removal effect is reed> Eichhornia crassipes> water peanuts.(4) By analyzing the changes in hillslope’s lose of runoff pollutants, it could find theconclusions that TN&TP’s concentration is max in the sloping fields, and followed by pine, oakand bamboo, means that bamboo is at the minimum. Second, the rates of sediment accumulationabout P elements is greater than N elements on sloping enrichment; and the ways of lossing Nelements are primarily through in run-off slopes, loss P element are mainly through in sediments.