北运河流域典型区污灌条件下氮素渗漏模拟及灌溉模式优选

为了揭示北运河流域农田氮素的渗漏迁移特征，为该流域水资源总体规划和非点源污染综合整治提供指导，以北运河流域武清区为研究对象，采用改进的SWAT模型对16种不同灌溉模式下农田氮素的渗漏特征进行模拟分析。结果显示，随着污灌次数的增加，氮素渗漏量也相应增加，但3次以下污灌，其变化不明显。在污灌次数相同，且连续污灌或者污灌间隔...

Nitrogen Percolation Simulation under Sewage Irrigation and Irrigation Pattern Optimization of Typical Area in North Canal Basin

In order to reveal the characteristics of the farmland nitrogen percolation of the North Canal Basin,and provide some guidance for the basin's general planning of water resources and comprehensive control of non-point source pollution,the improved SWAT model was applied to simulate the characteristics of the farmland nitrogen percolation under sixteen different irrigation patterns in the Wuqing area in the North Canal Basin.The simulation results indicated that the amount of nitrogen percolation increases correspondingly with the increase of the sewage irrigation,which is inconspicuous when sewage irrigation less than thrice;While with the same number of the sewage irrigation and under the case of continuous or short time-interval sewage irrigation,the amount of the nitrogen percolation is relatively larger.And the amount of the nitrogen percolation is relatively smaller if irrigating sewage in the returning green stage or the jointing stage of the winter wheat,or in the tasseling stage of the summer maize.Besides,the rainfall and irrigation amount are the key factors determining whether the NO-3-N leaches and the leaching amount,and in the absence of adequate rainfall recharging the soil water storage,a proper irrigation amount would not cause excessive water percolation and NO-3-N leaching loss.The proper irrigation pattern of the Wuqing area is irrigating sewage in the returning green stage or the jointing stage of the winter wheat,while irrigating clean water in the rest growth stages,and irrigating sewage in the tasseling stage of the summer maize.