The Agriculture Non-point Pollution Study In Yellow River Basin's Lanzhou Reach

Agriculture non-point pollution has been generally occurred over an intermittent period of time from diverse sporadically sources, and often correlated with climatic events. Nowadays it becomes an important pollution source to influence water quality, and a threat to lead to deteriorate water quality.Yellow river basin's Lanzhou reach is selected as the study area in this paper. By evaluated the water quality of Yellow river's Lanzhou reach using gray clustering technique , this paper draws a conclusion that Non-point source pollution has been affecting the water quality of the Yellow River. And according to the statistics of Yellow river's Lanzhou reach region from 2001 to 2006, this paper analyzes the affecting factors, including fertilizer run off, rural domestic waste, poultry and livestock farm and soil erosion, and their contribution to TN,TP of non-point source pollutant. Moreover, the annual total load and time distribution have been obtained . Based on the analysis , it shows the contribution rates of each non-point sources to TN and TP, then it analyses the space distribution of TN and TP of Yellow river's Lanzhou reach region by GIS.At last, aiming at the feature of agriculture non-point pollution, some non-engineering and engineering technology Countermeasures against non-point source pollution were presented in this paper.