Experimental and Modeling Study on the Agricultural Pollution Export from a Small Watershed

Agricultural nutrients including nitrogen and phosphorous are quit important sources for the water pollution and eutrophication in Taihu Lake Watershed. To investigate the export mechanism of the agricultural non-point source pollution, a small watershed name Meilin Watershed was chosen to do the field experiment. The comprehensive hydrology and pollution processes on the watershed were measured, and with the dataset physically based model was established. The results show that: The sediment, organic nitrogen and organic phosphorous mainly export from the hill slops where the rain-runoff erosion is strong; Dissolved phosphorous coms from the area near the stream with much fertilization; Nitrate spread widely and easy to get into water by eluviation, and the main source is the area where near the river stream and the hill slops where easy to produce runoff when rain come down.