A novel semi-analytical approach for non-uniform vegetated flows

In this paper a semi-analytical approach is proposed to understand the mechanism by which a non-uniform vegetated flow passes over a finite thick soil layer covered with grass. The flow region is divided into three layers: a homogenous water layer, a mixed water-grass layer, and a finite thick soil layer (hereafter referred to as the water layer, the grass layer, and the soil layer). The flow of the water layer is governed by the Navier-Stokes equations. Both the grass and soil layers are regarded as porous media and the Biot's theory of poroelasticity is applied to the porous medium flow. The semi-closed solutions are then obtained by the Runge-Kutta method. The drag force induced by the flow through the grass layer and the flow profiles of three patterns: submerged grass, emergent grass and mixed type are also discussed. (C) 2013 Elsevier Ltd. All rights reserved.