Solutions for Miscible Displacement of Soil Water with Time‐Dependent Velocity and Dispersion Coefficients

Abstract

Abstract Miscible displacement processes with time‐varying velocity and dispersion coefficients are examined. Simplified solutions utilizing arbitrary initial conditions are presented and used to simulate step and slug inputs of solutes into soil during infiltration of water. The solutions are used in the analysis of experimental data, both for field infiltration with a slug of solute and for psychrometric measurements of salt fronts in a laboratory sand column. Experimental data obtained for solute movement was more accurately described using time‐increasing dispersion relationships than for constant values.