非均质土壤饱和稳定流中盐分运移的传递函数模拟

Transfer Function Model on Chloride Transport in Heterogeneous Saturated Soils under Steady Flow

对室内人工构造的两种非均质土柱 ,以传递函数模型作为模拟手段 ,研究了稳定流场中饱和非均质土壤盐分优先运移的随机特征。首先计算了模型参数 μ和 σ2 ,获得了氯离子在非均质土壤中迁移时间的概率密度函数 ,然后应用传递函数模型对土柱中氯离子的出流浓度动态进行了随机模拟 ,并对非均质土壤中氯离子的均值和中值迁移时间及相应的运移体积与可动体积进行了分析和讨论 ,还依据质量守衡原理获得了土壤溶液中氯离子平均驻留浓度的变化。

The experiments were done for the purpose of analyzing saturated solute transport in the heterogeneous soil. Two kinds of heterogeneous soil columns (48cm×48cm×40cm) were irrigated with 0 027 Mol/L CaCl 2 solution when steady flow occurred in the soils. The breakthrough curves data were obtained. The parameters of the model were calculated, and the probability density functions of the logarithm of travel time of chloride were derived. In addition, the simulated data of breakthrough curve of the chloride in heterogeneous soil were computed using the transfer function model. Finally, the transport volumes of Cl -, mobile volume and the volume averaged concentrations in the soil solution were estimated.