Comment on “Analytical solutions to one-dimensional advection–diffusion equation with variable coefficients in semi-infinite media” by Kumar, A., Jaiswal, D.K., Kumar, N., J. Hydrol., 2010, 380: 330–337

The paper of investigated the advection and diffusion of solute in semi-infinite media with variable coefficients. They offered some analytical solutions for several sets of velocities and diffusion coefficients. Despite of its potential interest, the authors mistakenly made use of the transform of partial derivative between two coordinate systems, which made the part of “Temporally dependent dispersion along uniform and steady flow” wrong.