Comment on “Dispersion in stratified porous media: Analytical solutions” by A. N. S. A1-Niami and K. R. Rushton

AI-Niami and Rushton [1979] (hereafter eferred to as AR) treated solute transport in heterogeneous two-layered media. They studied the nonstationary case in a bounded domain (x and z direction) with a nonzero l ngitudinal hydrodynamic dispersion coefficient. While some 10 years have been passed since its publication, it has been cited a number of times for comparison toanalytic and experimental results [e.g., Wang et al., 1986]. In this comment, it will be Shown that he published solution C (see AR equation (6)) is in error in the sense •that •C satisfies the initial, boundary (except for x = L), and the interface conditions, but does not satisfy the differential equation. Alternatively, it will be shown that C•, C2 (see AR equation (6), where C• is the first and C2 the second Part of the expression for C) satisfy the initial and boundary conditions as well as the differential equation i the two layers respectively, butdo not satisfy the interface conditions.