洞庭湖农业面源污染排放特征及控制对策研究

Agricultural non-point source pollution discharge characteristic and its control measures of Dongtinghu Lake

为明确洞庭湖农业面源污染状况,运用输出系数法和等标污染负荷法分析、评价了洞庭湖区农业面源污染负荷,运用GIS软件绘制面源污染负荷空间分布状况,运用聚类分析划分污染类型,结果表明:2010和2014年洞庭湖区TN、TP年输出负荷总量分别为104556.9t,12719.02t;103643.71t,13032.79t;不同类型污染源产生TN负荷量大小顺序为:旱地>水田>畜禽养殖>农村生活>林地,不同类型污染源TP污染负荷量大小顺序为:畜禽养殖>旱地>水田>农村生活>林地;农业面源污染负荷主要来源是旱地和畜禽养殖,在空间上TN、TP污染分布一致,但各区域TN、TP年输出负荷量存在差异,以桃源县、汉寿、澧县,鼎城、南县、安化、华容、平江等区域输出负荷量高,是流域优先控制区,并基于聚类分析将ANP划分为4类污染类型,提出控制对策.

To clarify the spatial characteristics of agricultural non-point source pollution in Dongtinghu Lake.Pollutionloads from agricultural nonpoint sources in Dongtinghu Lake were estimated and evaluated according to the approach ofexport coefficient modeling as well as the equal standard pollution method.In addition,spatial distribution of non-pointsource pollution load was drew by GIS.The results demonstrated that total nitrogen and total phosphorus loads inDongtinghu Lake respectively were104556.9t/a,12719.02t/a;103643.71t/a and13032.79t/a in2010and2014.Themagnitude order of the contribution to various types of pollutant sources was as following,1)dry land>paddy field>livestock and poultry breeding>forest land>rural life for total nitrogen load;2)livestock and poultry breeding>dryland>paddy field>woodland>rural life for total phosphorus load,respectively.Dry land and livestock farming was themain source of agricultural non-point source pollution load.For the spatial regularity,the space TN,TP pollutiondistribution is consistent,but regional differences between TN and TP in the output load.The priority control areas wereTaoyuan county,HanShou,Lixian,Ding cheng,Nanxian,Anhua,Huarong,where the ANP output load was high.Withclustering analysis method,the agricultural non-point source pollution was divided into4types of pollution,and controlcountermeasures were put forward.