基于遥感与GIS技术的研究进展，采集洮河流域高程数据、土地利用类型、土壤类型特性、气象数据等，在SWAT模型中模拟与面源污染有关的降水、地表径流、壤中流、下渗和蒸散发等水文过程，计算侵蚀量、总氮和总磷等面源污染负荷，研究洮河流域面源污染特征。结果表明：洮河流域多年平均侵蚀量为0.70×108 t，多年平均总氮面源污染负荷为244.11 t，洮河流域多年平均总磷面源污染负荷为27.91 t，洮河流域1967—2017年多年平均侵蚀量、总氮面源污染、总磷面源污染负荷总体呈不明显的波动减少趋势，同时提出了改变土地利用方式、设置植被过滤带、坡改梯等面源污染防治对策及建议。
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 nonsource
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
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