湖北省江陵县农业非点源污染负荷特征研究

Characteristics of Agricultural Non-point Source Pollution Load in Jiangling County of Hubei Province

为探明湖北省江陵县农业非点源污染现状,运用改进输出系数法对该县农业非点源污染负荷量进行估算,并应用地理信息系统(GIS)直观分析了非点源污染负荷的空间分布状况。结果表明:总氮、总磷年负荷量随时间推移先缓慢上升达到最大后,于2016年略有下降;不同污染源对总氮污染负荷的贡献大小顺序为:农林用地>农村生活污水>畜禽养殖>淡水养殖,对总磷的污染负荷的贡献大小顺序为:农林用地>畜禽养殖>农村生活污水>淡水养殖;非点源污染高负荷区主要集中在县域中部和东南部,耕地上过量施用的化肥和畜禽养殖废水是该区域需要优先控制的主要污染源。

To clarify the current situation of agricultural non-point source pollution in Jiangling County,Hubei Province,pollution loads from agricultural non-point sources in the County were estimated by using modified export coefficient method.In addition,the spatial distribution status of non-point source pollution loads was analyzed by GIS.The results indicated that the total nitrogen(TN)and total phosphorus(TP)loads showed a slight upward trend over time,after reaching the top point,and it decreased slightly in 2016.The order of the loads to various types of pollutant sources for the total nitrogen loads was as follows:arable and forest land>rural living sewage>livestock and poultry sewage>freshwater aquaculture.While the order for the total phosphorus loads was as follows:arable and forest land>livestock and poultry sewage>rural living sewage>freshwater aquaculture.The high loads areas of non-point source pollution were mainly concentrated in the central and southeast of the county,and the overuse of fertilizers on arable land and livestock and poultry sewage were the major sources of pollution in the region that requires priority control.