SOLUTE TRANSPORT IN A COMPOUND OPEN CHANNEL WITH EMERGENT VEGETATION

Abstract

The present study investigates the solute transport mechanism in a vegetated compound channel. In this paper three-dimensional numerical simulations involving solute transport models in a partially vegetated open channel flows are presented. Vegetation zones were prepared fully covering the floodplain and as a vegetation belt on one side of a compound channel to identify the mixing mechanism. For flow simulation a non-linear k-epsilon model coupled with a vegetation model is used. For solute transport an eddy diffusivity model and an algebraic scalar flux model by Daly-Harlow are implemented and the performance of each model is evaluated. The numerical results are favorably compared with the experimental observations in terms of solute concentration. It is found that Daly-Harlow model taking into account the anisotropy of turbulence shows better performance over an eddy diffusivity model in complex flow fields.