Article Information
Impact of Vegetation Density on Flow Characteristics in a Straight Compound Channel

Keywords: Vegetation, Compound Channel, Velocity Profiles, Wall Shear Stresses, Reynolds Stresses

Mehran University Research Journal of Engineering & Technology

Volume 32 ,  Issue 4

USMAN  GHANI,SHAHID ALI  ,ABID LATIF  

Abstract

Vegetation exists on the floodplains of almost all natural channels. This vegetation results in a number of changes in flow features of open channel flows. Sometimes vegetation also exists within the main channel. This paper presents a numerical study in which the impact of vegetation density on different flow features has been considered. The variables investigated included velocity profiles, bed shear stresses, Reynolds stresses and side wall shear stresses. A compound channel with floodplain on both sides of the main channel has been considered. Four different vegetation densities were considered in this work. It was revealed that increase in vegetation density results in a decrease in the velocity values close to the bed and in the upper regions of the flood plains. The Reynolds stresses were also influenced considerably in the lower regions of the channel. Similar patterns were observed in case of bed shear stresses. The vertical profiles of side wall shear stresses were also investigated in this work. Such an investigation will help in enhancing the understanding and improving different conveyance and flow resistance calculation formulae.