格林-安姆普特（Green-Ampt）模型原理简单、使用方便，在浅层滑坡的降雨入渗分析中有很大的应用潜力。渗透系数是Green-Ampt模型中的一个主要参数，该渗透系数并不一定等于土体的饱和渗透系数。通过与理查茲（Richards）方程求解进行比较，研究了Green-Ampt模型中渗透系数的取值方法。研究发现，为获得与Richards方程相同的入渗量计算结果，需对饱和渗透系数进行修正，该修正系数的大小与入渗深度和土体类型有关。对于文中研究的土体，当Green-Ampt模型中渗透系数取为0.7倍饱和渗透系数时，由Green-Ampt模型计算的孔隙水压力分布与Richards方程计算结果最为接近，建议Green-Ampt模型中渗透系数修正系数取0.7。

The Green-Ampt model is a simple method for infiltration analysis. Due to its ease to use, the Green-Ampt model is potentially very useful for the prediction of slope failure under rainfall infiltration. A key parameter in this model is the permeability coefficient, which is different from the saturated permeability of the soil. This study investigates the relationship between the permeability coefficient in the Green-Ampt model (kg) and the saturated permeability coefficient of the soil (ks) through comparison with results from the more accurate Richards’ equation. The ratio of kg to ks is called the permeability coefficient adjusting factor. It is found that the adjusting factor depends on the factor of the duration of the rainfall as well as the soil type. For the soil studied in this paper, an adjusting factor of 0.7 seems to be optimal in reproducing the pore pressure distribution calculated based on Richards’ equation.