Numerical Solution to Advection-Dispersion Equation with Transient Storage Zones, Considering Unsteady Flow in Irregular Cross Section Rivers

Abstract

For accurate simulation of transport in natural rivers, some revisions have to perform in classical advection dispersion equation and some terms for considering of transient storage zones added to this equation. In this study a new and comprehensive model that merges numerical schemes with higher order accuracy (QUICK scheme) for solution of advection dispersion equation with transient storage zones in rivers with irregular cross sections at unsteady flow regime is presented. The presented method is verified by analytical solution, hypothetical example and two sets of real data. The results of verification implied that presented model have reasonable accuracy in simulation of contaminant transport in this condition. Also with implementation of model in the case of pure advection and comparing the results with two other numerical model results that use from centered difference method in spatial discretization of equations the ability of presented model in more accurate simulation in this case is shown. Results show that presented model in this study, is an applicable model and could be suggested as alternative for common present models at contaminant transport studies in natural rivers and streams.

Keywords

• advection-dispersion equation
• transient storage
• numerical solution
• unsteady flow
• quick