夹砂层土壤膜孔灌水分入渗规律数值模拟与试验验证

Numerical simulation and experimental validation of sand-layered soil water infiltration under film hole irrigation

为认识膜孔灌条件下具有砂质夹层土壤的水分入渗规律,应用非饱和土壤水动力学理论,基于Richard方程建立了膜孔灌夹砂层土壤水分入渗数学模型,利用SWMS-2D软件求解,并采用平均绝对误差(MAE)、均方根误差(RMSE)、偏差百分比(PBIAS)和纳什效率系数(NSE)对累积入渗量、湿润锋运移距离和土体剖面含水量的实测数据与模拟数据进行统计分析。结果表明:MAE值和RMSE值接近0,PBIAS<10%(PBIAS=-6.36%^-0.81%),NSE接近1(NSE>0.97),表明两者具有较好的一致性。所建模型可以较准确地反映夹砂土体膜孔灌水分入渗状况,证明SWMS-2D可以作为研究工具来模拟分析夹砂土体膜孔灌土壤水分入渗特性。

In order to understand the rule of sand-layered soil water infiltration under the film hole irrigation,the sand-layered soil water infiltration mathematical model based on Richard equation was established according to the theory of unsaturated soil water dynamics,and the SWMS-2D software was used to solve the model.The Mean Absolute Error（MAE）,Root mean Square Error（RMSE）,Percent Bias（PBIAS） and Nash-Sutcliffe Efficiency（NSE） were used to evaluate the simulation data and measured data of cumulative infiltration,soil wetting front and soil moisture content.The results show that MAE and RMSE is close to 0,PBIAS is less than 10%（-6.36%^-0.81%）,and NSE are close to 1（0.97）,which indicate that the measured data was consistent with the simulation values.The model can accurately reflect sand-layered soil water infiltration under film hole irrigation,and SWMS-2D can be used as a research tool to simulate and analyze the infiltration characteristics of sand-layered soil water movement under the condition of film hole irrigation.