中文摘要：

根据氨挥发机理建立了氨挥发子模型,与氮素运移转化模型Nitrogen-2D进行耦合,改进并完善了Nitrogen-2D模型的氮素转化过程。运用改进的模型模拟再生水灌溉冬小麦生长季中土壤水分、铵态氮和硝态氮的运移和转化过程。模拟结果与未经改进的模型模拟结果及实测值进行了对比。结果表明改进的模型模拟值与实测值的均方根差比未经改进模型的大幅度减小,铵态氮模拟精度有较大程度地提高。将改进的模型模拟铵态氮挥发速率和氨挥发累积量,得出模拟时段氨挥发过程。经比较分析,模拟结果正确、合理,可用于农田氮素损失预测和污染分析。

英文摘要：

According to the ammonia volatilization principle,a submodel of ammonia volatilization was suggested and coupled with the nitrogen dynamic model Nitrogen-2D to establish a modified model for improving the simulation of nitrogen transformation process.The modified model was used to simulate the distribution of water content,ammonia concentration and nitrate concentration in the soil profile under the condition of sewage irrigation.The comparison of simulated results with measured value and simulation result of the initial model,shows that the root mean square error was decreased obviously.It indicates that the accuracy of ammonia concentration simulation was improved by the modified model.The changing process of the ammonia volatilization rate and cumulative NH3 loss was calculated by using the medified model.The mass balance analysis shows that the calculated results is correct and reasonable.The modified model can be applied to nitrogen loss analysis and pollution risk assessment.