Study On The Simulation Of Agricultural Non-point Source Pollution In Shuangyang River Watershed Of Songnen Plain

With the effective control of industrial and non-point pollution has been the major residentialpoint source pollution, factor of water pollution. As the agricultural NPS is the most importantfactor for water environment deterioration and lake eutrophication in China, more and morescientists and technologistsfocus on the control countermeasure and pollulion mechanism ofagricultural non-point source.Studying and Applying advanced non-point sources pollution modelin China is not only the need of theoretical study of NPS pollution model,but also the need of thepractices of NPS pollution control in China.This dissertation chooses Shuangyang river watershed as an object, proceed from agriculturenon-point pollution inventory survey, evaluates the water quality of Shuangyang river byintroducing gray clustering technique.The result of water quality have already severecontamination,and draws a conclusion that agriculture non-point pollution is an important pollutionsource to influence the water quality of Shuangyang river.The basic databases and special plots ofthe representative drainage area are completed with GIS software, and space parameters forAnnAGNPS model are picked-up by GIS's analyse and tidy technology of the space data.The latest AnnAGNPS model is used, and the agricultural non-point source is simulated.Itcontains the load of sediment, nitrogen, phosphorus. The feasibility to use this model inShuangyang river watershed. Moreover, the total load,time distribution and space distribution ofsediment,nitrogen,phosphorus of Shuangyang river watershed have been obtained. The main resultsas follows:1. The average annual load of TN is 2319.71t/yr, TP is 154.61t/yr and total sediment is120893.15t/yr.2. Characteristics of nitrogen and phosphorus losses from Shuangyang river watershed werediscussed.The time distribution of the pollutional load is maldistribution.One peak time is betweenJune and August.To Shuangyang river watershed, nitrogen and phosphorus losses occurred betweenJune and August. Nitrogen occupy 53% of YEAR-ROUND, phosphorus occupy 58% ofYEAR-ROUND, sediment occupy 60% of YEAR-ROUND.3. AGNPS model has been used into the management practices evaluation.Several programme have been made quantitative assessment with the AGNPS before and after applied,this methodgives the scientific basis for non-point source pollution controlling measures.It find that thecombine of the both follow river mount vegetation filter bag and contour line meadow amortisationcan reduce non-point source pollution load.Toward for the question of agricultural nonpoint source pollution,theses macroscopic viewsummarize non-point pollution countermeasures of control and management.This study couldprovide assistances to the theoretical study of watershed NPS pollution control and management, aswell as the raising of practical management measures for NPS control in the study area and otherareas.