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传统Green-Ampt入渗模型由于假设过于简化而限制了计算精度,针对这一问题,在分层假设的基础上对模型进行了改进:将均质入渗土壤分为饱和层、过渡层和干土层,采用Richards模型分析了不同入渗条件下各层的厚度以及各层内含水率和导水率的变化规律,结果表明,入渗条件一定时,过渡层占湿润层(包括饱和层和过渡层)比例会随湿润层厚度的增加线性减小,积水深度和土壤初始含水率分别会影响这一线性关系的纵轴截距和斜率,而土壤饱和导水率则对其没有明显影响;过渡层内土壤含水率分布为椭圆形曲线,而导水率随深度增加线性减小。在此基础上,通过引入湿润层的等效导水率并相应给出锋面吸力的计算方法,对传统Green-Ampt模型进行了改进。结果显示,改进后模型计算精度显著提高。
The traditional Green-Ampt infiltration model, which is limited by the simplification of the assumptions, has limited the calculation accuracy. Based on the assumption of stratification, the model is improved on the basis of the assumption that the homogeneous infiltration soil is divided into saturated layer, transition layer and dry layer Soil layer, the Richards model was used to analyze the thickness of each layer under different infiltration conditions and the variation of water cut and water conductivity in each layer. The results show that when the infiltration conditions are constant, And the transitional layer) will decrease linearly with the increase of the thickness of the wetting layer. The depth of the water and the initial soil water content affect the vertical intercept and slope of the linear relationship respectively, while the soil saturated hydraulic conductivity is not obvious The distribution of soil water content in the transitional layer is oval curve, while the hydraulic conductivity decreases linearly with depth. Based on this, the traditional Green-Ampt model is improved by introducing the equivalent hydraulic conductivity of the wetting layer and calculating the fringing suction. The results show that the accuracy of the improved model is significantly improved.