| Popis: |
The results of a study on the hydrodynamic dispersion of ionic solutes in unsaturated porous media are presented. This study concerns the description of solute transport in moving coordinates, the application of the radiometric method to measure the water content and solute density in unsaturated soil, the verification of the theory of solute transport in the aeration zone. The application of moving coordinates has permitted the elimination of the convection term from the transport equation, which leads to more simple numerical procedures. This is due to the absence of the so-called numerical dispersion, which is present in the classic approach and brings about substantial errors. The radiometric method of monitoring has allowed to simultaneously measure the distribution of water content and solute density in the undisturbed soil sample. The experimental results have shown a linear relationship between the coefficient of dispersion and pore-water velocity for a given water content, and a linear dependence of the dispersion coefficient on the water content for a constant pore-water velocity. |
