瑶湖流域非点源氮、磷负荷估算及其控制对策

利用ArcGIS10.0软件,划分了瑶湖流域的范围,并提取了土地利用类型及其面积,在流域调查的基础上,参考国内外相关研究方法,按照农村与城镇生活污染(A类污染)、畜禽养殖污染(B类污染)、村镇与农业径流污染(C类污染)和水产养殖污染(D类污染)等4种污染来源,估算了瑶湖流域的非点源氮、磷污染负荷。结果表明:入湖氮、磷总负荷分别为346.3 t/a和102.8 t/a;B类污染是氮和磷污染的主要来源,其污染负荷占总负荷的比例分别为73.1%和85.3%;南昌县对B类污染的TN和TP贡献率大于青山湖区;南昌县对A类污染的TN和TP贡献率稍小于青山湖区;对于C类污染,TN贡献率大小为:水田村镇水浇地,TP贡献率大小为:村镇水田水浇地。在此分析基础上,提出了非点源N、P污染负荷控制对策。这为瑶湖流域水污染控制提供了理论依据和数据支撑,同时也为政府制定区域社会经济发展规划提供了决策依据。

Estimation and Control Strategies of Non-point Nitrogen and Phosphorus Load in Yao Lake Basin

ArcGIS was adopted to divide the range of Yao Lake basin, and extract the types and areas of land use. Based on the filed survey, according to the pollution of rural and urban life （ class A）, livestock and poultry breeding （class B）, rural and agricultural run-off （class C） and aquaculture （class D）, estimated the non-point of nitrogen and phosphorus load by referring to the relevant domestic and foreign estimation methods. The results showed that： the pollutant loads of the non-point nitrogen and phosphorus were 346.3 t/a and 102.8 t/a respectively. Class B is not only a major source of non-point nitrogen for Yao Lake basin, but also the phosphorus, which accounts for the 73.1% and 85.3% higher than of total pollution load respectively. The contribution of class B of Nanchang country is Qingshanhu district, while the contribution of class A of Nanchang country is lower than Qingshanhu district. As for class C, the contribution of nitrogen in Yao Lake basin can be ordered as ： paddy 〉 villages and towns 〉 Irrigated, while the contribution of phosphorus can be ordered as ： villages and towns 〉 paddy 〉 Irrigated. On the basics of these analyses, control strategies of non-point source nitrogen and phosphorus was proposed. This research provides theoretical basis and data support for water pollution control in Yao Lake basin, and also decision making for the government to develop regional socio-economic development plan.