斜坡降雨入渗的改进Mein Larson模型
The Landslide Rain Infiltration Based on the Improved Mein Larson Model

土壤初始含水率分布是影响湿润锋下移的重要因素之一.传统的降雨入渗模型仅假定初始含水率均匀分布，并没有考虑非均匀分布的情况.以Mein Larson降雨入渗模型为基础，假定初始含水率随垂直于坡面方向深度呈线性分布，推导了一种新的滑坡降雨入渗函数，弥补了原模型只能用于初始含水率均匀分布情况下的不足.研究结果表明：初始含水率分布对湿润锋下移有较大影响，在初始含水率呈线性分布的情况下，坡体表面含水率越大，含水率随垂直于坡面方向深度的变化率k值越接近零，湿润锋下渗速度越快，当k=0时，新模型退化为Mein Larson降雨入渗模型，证明Mein Larson降雨入渗模型是新模型的一个特例.与有限元法得到的结果对比表明，提出的降雨入渗新模型计算的湿润锋下渗深度与数值解结果相接近，证明了该方法的可靠性.
The initial soil moisture content distribution was one of the important factors that affect the moving down of wetting front. Traditional rainfall infiltration model only assumed that the initial moisture content was uniform and the situation of non uniform was not taking into consideration. Based on the Mein Larson rainfall infiltration model, this paper deduced a new landslide rainfall infiltration function by assuming the initial moisture content distribution linear with the increase of perpendicular to the direction of slope surface depth. It made up for the original model that only applied to the situation of uniforminitial moisture content distribution. The result showed that the initial moisture content distribution had large effect on the moving downof wetting front. In the case of initial moisture content was linear distribution, the greater the slope surface moisture content, the value of k which was the one of fitting parameters was closer to the zero, the faster the wetting front infiltrated. When the value of k equaled to the zero, the new model changed to the Mein Larson rainfall infiltration model. It proved that the Mein Larson rainfall infiltration model was a special case of the new model. Compared with the result of FEM, the results of the calculation model agree with that of FEM. It proved the reliability of the new model