摘要
本文根据宏观尺度条件下溶质运移的随机特征，在不考虑孔隙弥散的条件下，对一维非饱和溶质运移方程进行了简化．假设流速场及溶质浓度均为空间平稳随机函数，通过对一维非饱和溶质运移的简化方程进行平均处理，导出了与小尺度对流－弥散方程相似的宏观尺度溶质运移的基本方程，并由谱分析导出了宏观弥散系数及溶质浓度方差的表达式．应用宏观尺度溶质运移方程为基础的数学模型对野外盐分迁移过程进行了模拟，模拟所得的溶质平均浓度及浓度方差与实测结果吻合良好．
In this paper, one-dimensional unsaturated solute transport equation is simplified without considering the pore scale dispersion. Assuming that the velocity and concentration fields are statistically homogeneous, a macroscale unsaturated solute transport equation is derived by averaging the local simplified equation over the ensemble, which is similar to the small-scale convection-dispersion equation.Spectral analysis is used to evaluate the macrodispersive coefficient and concentration variance. The model based on the macroscale unsaturated solute transport equation is applied for simulating the salt transport process at a field site in north of China. Numerical simulations have been carried out, the mean and the variance of concentration are consistent with the results of field observations.
出处
《水利学报》
EI
CSCD
北大核心
1995年第11期1-7,16,共8页
Journal of Hydraulic Engineering
基金
国家自然科学基金
水利水电科学基金
关键词
土壤
溶质运移
非饱和溶质运移
随机模型
谱分析
stochastic model, maeroscale, macrodispersive cofficient, solute transport, spectral analysis.
