应用HYDRUS-1D模拟砂质夹层土壤入渗特性

依据非饱和土壤水分运动理论，采用HYDRUS-1D软件，对砂质夹层土壤入渗特性进行数值模拟，分析各因素对砂质夹层土壤入渗规律的影响。结果表明：砂质夹层结构对土壤入渗特性有较大影响，具有暂时的阻水和减渗作用；湿润锋穿过砂层上界面后，入渗过程变为稳渗阶段，稳渗率主要受砂层质地、砂层埋深和压力水头影响，与土壤初始含水率和砂层厚度无关；砂质夹层土壤剖面水分分布不连续，上层土壤基本饱和，砂层土壤未饱和，土壤剖面含水率主要受砂层质地、砂层埋深和砂层厚度的影响。研究结果可为农业水资源利用及工程防渗技术提供理论依据。

Simulation of infiltration characteristics in soil with sand interlayer using HYDRUS-1D

Based on the theory for water movement in non-saturated soil, the HYDRUS-1D was applied to simulate the infiltration characteristics under soil with sand interlayer. The impact of each factor on soil infiltration law of soil with sand interlayer was analyzed. The results showed that: sand interlayer structure has great effect on soil infiltration characteristics, with a temporary effect on water-blocking and reduced infiltration. The process of infiltration will turn to steady infiltration stage when the wetting front passes through the upper interface of sand layer. The steady infiltration rate is affected by the sand layer texture, sand layer burial depth and pressure head, and regardless of the initial soil water content and sand layer thickness. Soil water distribution in profile of soil with sand interlayer is not continuous, the soil of upper layer is basically saturated, and soil of sand layer is unsaturated. Soil profile moisture is mainly affected by sand layer texture, sand layer burial depth and sand layer thickness. It provides theoretical basis for agricultural water resource utilization and engineering seepage control technique.