Study On The Agricultural Non-point Source Pollution Section Of The Trunk Stream Of Songhua River In Jilin Province From 2009 To 2014

Agricultural non-point source pollution is closely related to temperature,precipitation and other factors often accompanied by the characteristics of intermittent,randomness,complexity universality and so on,which has become the main reason of water pollution and brought a big threat to the health of water quality.Taking Jilin Province agricultural non-point source pollution of Songhua River basin as the research object,and according to the statistical information of 14 city and county in 2009-2014 and precipitation data from weather Stations yearly and monthly,this paper analyzed the non-point source pollutants TN,TP load contribution came from pollutant source of fertilizer application within basin,livestock breeding,rural life,soil and water loss,etc and studied the distribution characteristics of TN,TP load produced by agricultural non-point source pollution in time and space of Songhua river basin in Jilin province by using the universal soil loss equation RUSLE,empirical model,emission coefficient method and EXCEL and ArcGIS software and others.The results show that:(1)The TN,TP load contribution produced by chemical fertilizer of Songhua river basin in Jilin province from 2009-2014 was increased totally,the maximum value appeared in 2013 of TN load and in 2010 of TP load,the minimum value was all in 2009,the pollution value of Nong'an county,Yushu city,Qianguo county and Fuyu county was more,which had a significant contribution to the non-point source pollution of the whole study area caused by fertilizer application;The variation of TN and TP load caused by livestock and poultry were similar,TN,TP load changes in showed "V" type during 2009-2011,and the TN and TP curves were not obvious in the last 3 years,in addition,TN,TP are the smallest in 2010,the maximum value in 2009.(2)The variation trend in TN,TP load contribution of Songhua river basin in Jilin province in 2009-2014 caused by rural life was basically the same,descended slightly overall,the maximum value of TN,TP load appeared in 2009,the minimum value was in 2013.The variation trend of TN,TP load contribution caused by soil and water loss showed "M" within the 6 years,and the maximum value of TN,TP load was all appeared in 2010,but the minimum value was in 2009.The soil and water loss is directly related to rainfall and the largest rainfall is in 2010 in the 6 years.(3)The contribution of TN and TP load of agricultural non-point source pollution in the region was the same from large to small,that followed by the application of chemical fertilizer,livestock and poultry breeding,the soil and water loss and rural life.The area with the largest contribution of TN load was Yushu city,TP was Nong'an county,and the areas with the least contribution of TN and TP were Songyuan city and Yongji county;while the maximum load per unit area of TN and TP in Dehui city,the minimum values of TN and TP were found in Jiaohe city and Huadian city respectively;Although the annual load of TN and TP pollution in Songyuan city is at the end,but the unit area of TN,TP load is relatively high,located in the middle of 14 cities and counties.