土壤溶质迁移的指数函数模型

边界层方法是描述土壤溶质迁移的简单方法,通过边界层距离与时间的关系可以估计溶质迁移参数。基于边界层方法,研究了土壤溶质迁移的数学模拟及相应参数估计问题。假定土壤溶质浓度剖面为指数函数,得到了描述溶质浓度分布的指数函数模型。各参数对边界层距离的影响分析表明,应选取较小的孔隙水流速度、短历时推求土壤溶质迁移参数;对不同模型预测土壤溶质分布进行比较,结果表明,在短距离处指数型解与精确解的误差比其它都要小。误差分析表明了指数函数模型的有效性和实用性。

Exponential Function Model of Soil Solute Transport

The boundary layer theory is a simple model to describe solute transport in soil.The solute transport parameters can be estimated through the boundary layer changes over time.Modeling the solute transport in soil and estimating the transport parameters are the important goals of this research based on the boundary layer method.A soil solute transport exponential function model was developed based on assumption of exponential concentration profile.The effects of all parameters on boundary layer distance with time were analyzed.The results showed that the smaller pore-water velocity and the shorter duration should be selected to compute soil solute transport parameters.Equations describing soil solute concentration profile were compared with an exact solution.The results indicated that the errors of exponential solution were less than others at the shorter duration.The proposed model for estimating parameters and describing solute concentration distribution of solute transport in soil proves to be useful by error analysis.