微孔渗灌土壤水分运动的数值模拟及其应用

建立了含有第3类动边界条件的二维渗灌土壤水分运动数学模型,模型得到了试验的验证,具有较高的精度。模型计算结果表明:供水压力、管壁透水系数和初始土壤水势对土壤水分运动的影响具有显著差异。随着供水压力和管壁导水系数的增大,湿润区范围、湿润区内土壤平均含水率和累积渗水量均相应增加。初始土壤水势越高,湿润区范围、湿润区内土壤平均含水率越大,但累积渗水量却越小。最后结合保护地试验,确定了保护地番茄渗灌栽培的最佳渗灌管设计埋深。

Numerical Simulation and Application of Soil Water Movement under Subsurface Irrigation with Porous Pipe

In this paper,two dimension soil water movement mathematical model with boundary of the third type was built to simulate infiltration of subsurface irrigation with porous pipe.The model was verified and had higher precision.The calculating result of model indicated that soil water movement depended on water supplied pressure,initial soil water potential and permeability coefficient strictly.With the increase of water supplied pressure and permeability coefficient,the wetting range was enlarged,and the average water content within the range and accumulated amount of infiltration became higher.The higher the initial soil water potential was,the larger the wetting range and the more water content were,but the less the accumulated amount of infiltration was.The optimal depth of porous pipe in tomato cultivation was gotten through the integrated experiment in the protected field.