The Study On Non-point Source Pollution Of Typical Small Watershed In Zuli River

Non-point source pollution will cause the river eutrophication, reduce the waterquality level，further affect the industry and agriculture production and the health ofthe people. ZuLiHe is a river that the water quality is below class V. In order to studynon-point source pollution problems of ZuLiHe basin, with system theory, hydrologytheory and water and soil conservation theory as guidance, with Anjiagou watershedas experimental site, with the two methods of the water quality test and the modelsimulation, and with the combination between field monitoring and analysis indoor,including the test of runoff in the20plots, the non-point pollutant load of slope runoffand channel runoff are analyzed. At last, the main conclusions are in the thefollowing.(1)Through the water quality test and analysis on20runoff plots in the Anjiagouwatershed. It is found that the whole water quality exceed bid in2006. From view of3years continuous observation of the15runoff plots water quality, The number ofbelow class V increase from8in2006to11in2008, The number of below class Ⅳreduce from3in2006to1in2008. It is said that the runoff water quality is in thetrend of worsening over all. At the same time, the channel runoff water quality duringthe three year are all bellow Ⅴclass.(2)The mainly water quality exceeded items ot Farmland, arbor, shrub, grass, andnatural land are Permanganate Index, dissolved oxygen, ammonia nitrogen, nitritenitrogen, hexavalent chromium, volatile phenol and total nitrogen, etc.(3)Through the water quality observation on the slope runoff plots and gully runoff,the research estimate non-point source pollution load from slope and the channel inthe whole watershed.Calculations suggest that, the slope surface contaminants ofPermanganate Index, dissolved oxygen, ammonia nitrogen, nitrate nitrogen, nitritenitrogen, arsenic and phosphorus is the proportion of the gully contaminants load, Theproportion is77%,95%,62%,77%,80%,87%and50%.(4)The research have explored non-point pollution process simulation on Anjiagouwatershed by the SWAT model. The results show that there is big Error between theprediction results and the measured results, and the application of the model on thebasin, still need further exploration.