One-dimensional advection-diffusion equation : the convergence with the two-dimensional solution

Describes how fast the one-dimensional solution and the actual (width-averaged two-dimensional) concentration distribution converge in steady and oscillatory flow and whether this process is affected by the initial conditions. The one-dimensional advection-diffusion equation is used for the modelling of the dispersion of effluents in rivers and estuaries. With a two-dimensional velocity distribution.