南四湖流域种植业面源污染氮磷源解析研究

Source Apportionment of Nitrogen and Phosphorus from Cropping Non-point Source Pollution in Nansi Lake Basin

利用田间径流池采集南四湖流域种植业农田地表径流样品,分析其不同形态的氮磷数据,汇总数据得到南四湖流域种植业的氮磷源成分谱;并在南四湖区11条主要入湖河流入湖口处采集水样,测定氮磷含量,利用主成分分析法对南四湖流域种植业面源污染氮磷来源进行了源解析.结果表明,南四湖流域氮磷种植业面源污染来源有3种,3个主成分累积方差贡献率为95.275%.第一类污染途径为降雨淋溶小麦-玉米轮作农田产生的地表径流对河流产生的污染,这种污染的范围广且贡献率较大为50.220%;第二类污染途径为降雨淋溶大蒜-玉米轮作农田产生的地表径流流入南四湖入湖河流引起的,影响面也较广,贡献率为25.119%;第三类污染途径为自然降雨时,小麦-水稻轮作农田产生的地表径流对河流的污染,贡献率为19.937%.

Field runoff pools were used to collect the field surface runoff samples of different cropping systems in Nansi Lake region,and different forms of nitrogen（N） and phosphorus（P） data were analyzed.The source profiles of N and P in different cropping systems were also obtained by summarizing the experimental data measured in the current study.Samples were also collected from the 11 main rivers of Nansi Lake basin and the concentrations of N and P were determined.Principle component analysis（PCA） was applied to obtain cropping non-point pollution sources of N and P.The result showed that three types of N and P contamination sources were apportioned in Nansi Lake basin,explaining 95.275% of the total variance.The first source was from field surface runoff of wheat-maize rotation with a wide pollution range and a larger contribution,and it contributed 50.220% of the total contamination burden;the second type of N and P source was the water runoff pollution from garlic-maize rotation,were 25.119% contribution;the third source was the surface runoff from wheat-rice rotation,and it contributed 19.937%.