Two‐dimensional Transport of Solutes During Nonsteady Infiltration from a Trickle Source

Abstract

AbstractA simulation model for analyzing multidimensional simultaneous transfer of a noninteracting solute and water, applicable to infiltration from a trickle source, is developed. The equations describing transient two‐dimensional transport of a solute by diffusion and convection in unsaturated porous media are solved numerically by an approach that eliminates the effect of numerical dispersion. The noniterative alternating‐direction‐implicit finite difference procedure is used. Two mathematical models are considered: (i) a plane flow model involving the Cartesian coordinates x and z, and (ii) an axisymmetric flow model described by the cylindrical coordinates r and z. An example of transport in a homogeneous, isotropic and stable sand and loam soil systems is given. Results are shown for typical cases of trickle infiltration to demonstrate the effects of trickle discharge and soil‐hydraulic properties on the pattern of salt distribution in the wetted soil zone. The numerical results show that the approach presented may be useful in analyzing two‐dimensional solute transport processes in soils.