非饱和土壤水分函数解析与Richards方程入渗新解

Analysis of the Unsaturated Soil Moisture Function and New Interpretation of the Richards infiltration Equation

从土壤微现统计学角度出发，用各向均一无结构土壤“切片”孔径级配函数构建的统计毛管束模型和土壤水分分布依赖的力学原理。论证了理查兹（Ｒｉｃｈａｒｄｓ）方程中导水率、基质势、扩散率等水分函数和入渗率随充水度、土壤基质而变的机理、规律以及两者之间的内在联系，给出了相应的计算公式和可操作的参数分析确定方法。把迄今水分函数研究的纯经验相关现状提高到理论分析水平，使建立理论公式成为现实。给出的含有渗前上湿因子的新入渗公式可以取代截断误差不收敛的菲利浦（Ｐｈｉｌｉｐ）入渗公式。用文献［１］提供的萨庇（Ｓａｒｐｙ）壤土和吉里（Ｇｅａｒｙ）粉壤上实验成果，对文中结论做了验证。

Proceeding from the soil microscope statistics and by using the statistics capillary bunch model developed by the pore grading function with isotropic, homogeneous and unstructural 'soil slice' and the theory of mechanics depending on the soil moisture distribution, this paper proves the mechanism and law of moisture functions (such as hydraulic conductivity, matrix potential and diffusivity) in Richards Equation and the infiltration rate as well as their relation, which change with saturated degree and soil matrix. This paper also proposes the corresponding calculation equation and the determining approach on the parameter analysis for practical operation,promoting the existing pure empirical correlation about the study of moisture function so far to the level of theoryanalysis and made the establishment of theory formula into reality. The new infiltration formula, which contains soil moisture factor before infiltration, can replace Philip's infiltration formula whose truncation error is unconverged. With the experiment result on Sarpy loamy soil and Geary mealy loamy soil listed in reference [1],the conclusion is verified.