基于SWAT模型的梁滩河流域非点源污染负荷评价

Study on Non-point Source Pollution Load of Liangtan River Basin Based on SWAT Model

为掌握梁滩河流域氮磷污染物的时空分布特征,基于空间和气象数据构建流域SWAT氮磷负荷模型,并利用监测数据对模型进行率定和验证,借助投影寻踪法综合评价各子流域的主要非点源污染来源。结果表明:模型在研究区具有较好适用性,流域氮磷排放主要集中在丰水期(5—9月)且占全年的76%,氮磷负荷主要来自于农药化肥且以总氮排放为主。从空间上看,流域中部地区以地表径流污染为主,而西部地区水土流失较为严重,且污染负荷与泥沙排放量密切相关。

To grasp the spatial and temporal distribution characteristics of nitrogen and phosphorus pollutants in Liangtan River Basin,the SWAT(Soil and Water Assessment Tool)model of nitrogen and phosphorus load was constructed based on spatial and meteorological data.The model was calibrated and verified by monitoring data,and the main non-point source pollution sources of each sub-basin were evaluated by projection pursuit method.The results showed that the model had good applicability in the study area,nitrogen and phosphorus emissions were mainly concentrated in the wet season(May to September),accounting for 76%of the whole year.Nitrogen and phosphorus load was mainly from pesticides and fertilizers,and the total nitrogen emission was the main part.Spatially,surface runoff pollution was dominant in the central part of the basin,while soil erosion was more serious in the western part of the basin,and the pollution load was closely related to sediment discharge.