SWAT模型在洱海流域面源污染评价中的应用

重点污染区域和污染因子的识别是面源污染控制的基础. 通过将物理过程模拟及排污系数法计算进行整合，建立了SWAT模型,以描述农业生产活动与污染入湖量之间的关联关系，并以云南洱海流域总氮污染为例，使用验证后的SWAT模型模拟计算不同空间单元和不同农业生产活动对入湖TN的污染贡献系数，定量分析流域内各区域的农业面源污染源结构，识别洱海流域重点农业污染源和农业污染村镇. 结果表明，奶牛养殖、生猪养殖和大蒜种植是目前洱海流域内入湖TN污染的最重要农业污染源，占流域总污染负荷的66.12%. 对入湖TN污染贡献最大的6个村镇为江尾、右所、三营、玉湖、凤仪和喜洲，占流域总污染负荷的63.41%. 

Application of SWAT Model in Agricultural Non Point Source Pollution Investigation in Lake Erhai Watershed

The identification of key polluted areas and factors is the basis of non-point source pollution control.Based on physical processes simulation and the discharge coefficient method,the SWAT model was established to describe the relationship between agricultural production activities and pollution load into a lake.Lake Erhai watershed in Yunnan province was selected as the research area,and TN variation in the lake was calculated.The contribution coefficients of TN nonpoint source pollution to the lake by different spatial areas and different agricultural production activities were calculated with the verified SWAT model,and the pollution source composition in each spatial unit was calculated quantitatively.The key pollution sources and spatial units(administrative village in this study) were identified.The results showed that dairy cattle breeding,pig farming and garlic planting were the major agricultural pollution sources,contributing 66.12% of TN load to the lake.Six villages – Jiangwei,Yousuo,Sanying,Yuhu,Fengyi and Xizhou-contributed most to TN pollution in the lake,accounting for 63.41% of the watershed total pollution load.