推求土壤水分运动参数的简单入渗法──Ⅱ.实验验证

预报土壤中水分流动需要的土壤导水特性可通过观察水平土柱的入渗过程来确定，这一观测过程的分析是基于对Ｒｉｃｈａｒｄｓ方程求积分解。土壤水分特征曲线中的参数由观测的水平土柱和特征湿润长度和吸力为确定，非饱和土壤导水率由已确定的特征曲线中的参数和测定的饱和导水率导出。供试土壤有三种，它们的质地从砂壤到粘壤。由这种方法所确定的这三种土壤的水分特征曲线与实测的特征曲线符合良好，所确定的砂壤的非饱和导水率与实

A SIMPLE INFILTRATION METHOD FOR ESTIMATING SOIL HYDRAULIC PROPERTIES OF UNSATURATED SOILS Ⅱ. EXPERIMENTAL RESULTS

To predict water flow, knowledge of soil hydraulic properties is required. Horizontal infiltration of water into soil columns can be observed in order to determine hydraulic properties. Required physical and mathematical analysis of the observation is based on an integral solution of Richards′equation. The parameters of the soil water characteristic curve are estimated by the observed characteristic length of wetted zone and sorptivity. Unsaturated hydraulic conductivity is estimated from the parameters determined in the soil water characteristic curve and the measurement of saturated hydraulic conductivity. Three soils ranging from sandy loam to clay loam are included in this research. Soil water charactehstic curves for the three soils estimaed by the infiltration method are in good agreement with measured soil water characteristic curves. Unsaturated hydraulic conductivity, estimated by the infiltration method for the sandy loam, also compares well with measured values. To further check the method, water content of the three soils are calculated through the numeric method and the integral method based on the calculated hydraulic parameters. The calculation results indicate that the method is accurate.