Research Into The Agricultural Non-point Source Pollution Section Of The Yellow River In Lanzhou During 2007-2012

In this paper, by taking the Lanzhou section of the Yellow River Agricultural non-point source pollution as the research object, combining with the related data of 2007-2012, the application of chemical fertilizer, soil and water loss, TN,TP load of Lives tock and poultry breeding and rural life of four kinds of pollution sources were calculated, the load of TN and TP is got, and analyzes the trend in the change. And fertilizer funoff, soil erosion. Livestock breeding and and rural life of TN, the contribution rate of TP, and described by GIS TP TN, the spatial variation characteristics of pollutants load. The results are as follows:(1) The Yellow River Lanzhou section of generated by the application of chemical chemical fertilizer has been in a rising trend during 2007-2012, TN, TP load from TN4023.4 in 2007 t/a, TP957.94 t/a were increased to TN4757.46 t/a in 2012, TP 1132.74 t/a respectively; soil and water loss caused by the TN and TP load were presented "W" type,2008 and in 2010,2009,2007, the valley, peak in 2012;(2) TN, TP load changes caused by livestock and poultry are basically the same during 2007-2012, the peak reached 3931.57t/a,466.88t/a in 2007, declined in 2008, after a smooth trend; changes of 2007-2012 caused by TN and TP of rural life trend takes the shape of "A", the peak appeared in the in 2010, TN2135.6 t/a, TP252.89 t/a respectively; (3) The TN load is fluctuation bigly and the TP load is relatively stable of Yellow River Lanzhou during 2007-2012; TN TP load peak were 11717.88 t/a, 3047.75 t/a in 2007, TP and TN valley value of load are respectively 10312.05 t/a, 2358.79 t/a in 2008; TN, TP load achieve the peak in 2009, after that a slight rising trend;(4) The contribution rate of load TN’s in the order from big to small chemical fertilizer, livestock and poultry breeding (39.79%) (29.82%), rural life (19.26%) and 11.13% TP load source of soil and water loss; the size of the contribution is in the following order of fertilizer application, soil and water loss (38.68%) (36.35%) livestock and poultry breeding, rural life (15.45%) and (9.52%) in the study on regional agricultural sources of non-point source pollution;(5) The sequence of annual load in Lanzhou County TN is:Yuzhong county (4092.6t/a), Yongdeng county (3308.1t/a), Gaolan county (1437.1t/a), Honggu District (749.17t/a), Qilihe district (708.81t/a), Xigu District (426.1t/a), Chengguan District (150.07t/a), An ning District (134.56t/a); the corresponding TP load size sorting is:Yuzhong county (968.85t/a), Yongdeng county (814.1t/a), Gaolan county (459.57t/a), Honggu District (152.52t/a), Qilihe district (121.68t/a), Xigu District (76t/a), Chengguan District (23.32t/a), An ning District (20.9t/a).