变水头边界条件下土壤水分运动数值模拟

本研究提出了一种变水头条件下一维土壤水分运动数值模拟的边界处理方法，采用隐式差分法对基本方程进行差分离散，用迭代法求解非线性方程。在结合室内实验验证模型可用的基础上，分析了变水头条件下不同土壤初始含水率、不同初始水头高度下土壤水分的运动规律。结果表明，土壤初始含水率和初始水头对水分运动都有较大影响，作者提出的变水头边界处理方法可用于水分入渗历时和湿润锋的预测。

Numerical Simulation of Movement of Soil Moisture under Variable Water Head Boundary

The methods in relation to boundary condition of simulation area for one dimension numerical simulation of soil moisture movement under variable water head are suggested. Infinite difference technique was applied to solve the basic equation. The indoor experiments proved that the mathematical model is reliable. Through the mathematical model, the movement of soil moisture under variable initial soil water content and variable initial water head was analyzed. The results showed that initial soil water content and initial water head affected the movement of soil moisture remarkably. The methods of dealing with boundary condition of variable water head can be applied to the prediction of infiltration time and position of moist sharp point.