The non-point source (NPS) pollution is difficult to manage and control due to its complicated generation and formation. Load estimation and source apportionment are important and necessary for efficient NPS control. The pollution load model based on DEM, sub-basins, land use, soil type got with GIS tool and data from study and experiment was used to study pollution sources and calculate the pollution load of non-point source nitrogen and phosphorus in Jinjiang River watershed. The pollution loads of dissolved nitrogen and phosphorus from land runoff, rural domestic sewage and livestock discharge were calculated based on SLURP model and export coefficients model. And pollution loads of adsorbed nitrogen and phosphorus from soil erosion were calculated with USLE equation. The results showed the pollution load of non-point source nitrogen in Jinjiang River watershed was 12 298.95 t/a, most was dissolved nitrogen which taking up to 94.13%. The pollution sources were mainly interrelated with livestock discharge, agricultural field runoff and rural domestic sewage, which contributor ratios were 31.72%、 26.38% and 17.44% respectively. For non-point source phosphorus, its pollution load was 667.04 t/a and took up 56.73% and 43.27% for dissolved and adsorbed phosphorus respectively. Soil erosion, agricultural field runoff and rural domestic sewage were the main sources for phosphorus with contribution ratios of 43.27%、21.10% and 12.25% respectively. Therefore, soil erosion, agricultural field runoff and livestock discharge became the main pollution sources to influence load of non-point nitrogen and phosphorus in Jinjiang River watershed and should be controlled firstly.%计算流域非点源氮磷负荷并以此开展源解析对于水体污染控制具有重要意义.基于DEM数据,运用GIS工具划分子流域,提取土地利用和土壤类型等空间相关资料,通过调查及小区试验获取模型参数,建立晋江流域非点源氮磷污染负荷模型；利用SLURP模型和输出系数模型分别核算流域内不同景观类型土地输出径流和农村污染溶解态氮磷负荷,利用修正的USLE土壤侵蚀通用方程核算吸附态氮磷负荷,并进行污染源解析.结果表明:晋江流域非点源氮负荷为12 298.95 t/a,大部分为溶解态氮,占到了94.13％,主要来自畜禽养殖、农田径流和农村生活污水,其源贡献率分别为31.72％、26.38％和17.44％;非点源磷负荷为667.04 t/a,溶解态磷和吸附态磷对流域总磷负荷贡献比例相当,分别为56.73％和43.27％,主要来自土壤侵蚀、农田径流和农村生活污水,其贡献率分别为43.27％、21.10％和12.25％.总体分析表明,土壤侵蚀、农田径流和畜禽养殖是影响晋江流域非点源氮磷负荷的主要污染源,,亟待优先控制.
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