关键词: 洮河流域, 面源污染, SWAT模型, 防治对策

Abstract: Based on the research progress of remote sensing and GIS technology,the elevation data,land use types,soil type characteristics,and meteorological data in the Taohe River Basin in Qinghai and Gansu Province,China were collected.The precipitation,surface runoff,soil flow,infiltration,and evapotranspiration parameters relating to non-point source pollutions were simulated using SWAT model to calculate non-point source pollution loads of the erosion,total nitrogen and total phosphorus,and study the non-point source pollution characteristics in the Taohe River Basin.The hydrological cycle simulated by SWAT model was based on the water balance equation to predict the runoff of each hydrological response unit.We then calculated the total runoff of the basin,which improves the prediction accuracy and more accurately describes the physical processes of the water balance.The effects of long-term land management measures on water production,sediment yield,and agricultural chemical pollutant loads were predicted in the large-scale complex watershed of Taohe River Basin with different types of soil,land uses,and management conditions.The plant growth model in the SWAT model can be used to assess water and nutrient migration,plant evapotranspiration,and biomass/yield in the root zone.The intensity of erosion and sediment yield in each hydrological response unit were calculated using the modified universal soil loss equation-MUSLE.Finally,various forms of nitrogen/phosphorus migration and transformation were simulated in the basin,with nutrients entering the mainstream and migrating downstream via surface runoff and subsurface flows.Studies showed that the average annual erosion was 0.70 × 10⁸ t and the average annual total nitrogen and phosphorus of nonsource pollution loads were 244.11 t and 27.91 t,respectively in the Taohe River Basin.The average annual erosion,total nitrogen,and total phosphorus of non-point source pollution loads showed a decreasing trend with indistinct fluctuations.At the same time,countermeasures and suggestions for non-point source pollution prevention and control,such as changing land-use patterns,setting up vegetation filter belts,and changing slopes to terraces were propos

Key words: Taohe River Basin, non-point source pollution, SWAT model, countermeasures