用垂直入渗法推求Gardner-Russo模型参数

Estimation of parameters in Gardner-Russo model by vertical infiltration method

通过室内垂直入渗试验研究了3种不同质地土壤的垂直一维水分入渗特性,并基于Gardner模型表征的非饱和土壤导水率和Gardner-Russo模型表征的土壤水分特征曲线形式,结合非饱和土壤水动力学方程,推导了土壤水分垂直一维入渗时累积入渗量、入渗率和湿润锋之间的理论关系。在此基础上推求了Gardner-Russo模型中的参数,利用试验数据对模型中参数进行了敏感性分析。结果表明,该方法所求得的参数具有较高的精度,这为土壤水分运动参数求解提供了一种简单而准确的方法。

The characteristics of vertical one-dimensional soil water infiltration in 3 soils were studied through laboratory vertical infiltration experiment. Based on the soil water retention function of Gardner and the hydraulic conductivity function of Russo, and combined with hydrodynamics equation of unsaturated soil, theoretical relationships between cumulative infiltration, infiltration rate and wetting front under vertical one-dimensional soil water infiltration were developed. Meanwhile, the parameters of Gardner-Russo model for describing the soil retention curves were obtained based on these theoretical relationships. The sensitivity analyses for the parameters were carried out according to the experimental data. Results show that the accuracy of the parameters estimated by this method is fine. The proposed method provides a simple and precise method for calculating the soil water movement parameters.