中文摘要：

土壤大孔隙是土壤中一种普通存在的现象,土壤大孔隙体积虽然仅占土壤体积的0.1%～5%,但却很大程度上影响着水分及溶质在土壤中的运移.从物理机制出发,构建了考虑土壤大孔隙的下渗模型.将土壤分为基质流区、贯穿大孔隙流区和内集水流区.假定基质中的水流符合达西定律,贯穿大孔隙域的水流通过运动波方程来描述,内集水区为一端封闭的贯穿大孔隙,采用一维水平入渗方程描述大孔隙中的水入渗到土壤基质中.联立3个流区的水流方程,采用有限差分法求解该模型.最后利用人工模拟降雨实验验证所建模型的有效性.结果表明,所建下渗模型能够较好反映大孔隙土壤下渗过程.

英文摘要：

It is a common phenomenon that lots of soil macropores exist in the soil.Although their volumes only account for 0.1%-5%of the whole volume of soil,to a great degree,they impact on the migration of soil water and solute.Starting from physical mechanism,an infiltration model considering soil macropores is constructed.In this model,the soil is divided into matrix flow domain,permanent macropores flow domain and internal catchment.The assumption of the matrix flow according with Darcy＇s law is adopted;permanent macropores flow is described by kinematic wave equation;the internal catchment is regarded as one end of permanent macropores closed and infiltration water from macropores into soil matrix described by one-dimensional horizontal infiltration equation.Contacting flow equations of three domains,finite difference method is applied to solve the model.Finally,the validity of the model is verified by experimental data of actual rain-runoff experimental system.The results indicate that the infiltration process in the macropore soil can be well described by this model.