负水头条件下的土壤水分垂直一维入渗特性研究

通过室内模拟试验研究了3种土壤在不同负水头条件下的土壤水分垂直一维入渗特性,并基于Brooks-Corey模型,结合非饱和土壤水动力学方程,推导分析了负水头条件下土壤水分垂直一维入渗时累积入渗量、入渗率、湿润锋以及入渗时间之间的理论关系,并利用入渗试验资料检验了这些变量关系。同时,验证了Philip入渗公式在负水头条件下的适用性。研究结果表明:这些理论关系可以很好地描述负水头条件下的土壤水分垂直一维入渗特性。

Characteristics of vertical one-dimensional infiltration of soil water under negative hydraulic head

Characteristics of vertical one-dimensional infiltration of soil water in three soils under different negative hydraulic heads were analyzed through a laboratory simulation experiment. Based on the Brook-Corey model, coupled with the Darcy law and the Richard equation, theoretical relationships were developed to describe cumulative infiltration, infiltration rate, wetting front and infiltration time of vertical one-dimensional infiltration of soil water under a boundary condition of negative hydraulic head. With the help of the data obtained in the infiltration experiment, relationships between these variables were analyzed, and fitness of the Philip infiltration equation under negative hydraulic head was verified. Results show that these theories can be used to better describe the characteristics of vertical one-dimensional infiltration of soil water under negative hydraulic head.