Modelling the effects of emergent vegetation on an open-channel flow using a lattice model

A two-dimensional lattice model has been developed to describe the influence of vegetation on the turbulent flow structure in an open channel. The model includes the influence of vegetation density on the frictional effect of the channel bed and walls. For the walls, a semi-slip boundary condition has been considered as an alternative to overcome the no-slip boundary condition limitations in turbulent flows. The drag stress exerted by the flow on the vegetation as well as the gravity effect has also been taken into account. The proposed lattice model has been used to simulate the experimental results reported from the study of the influence of alternate vegetated zones on the open-channel flow. The results show that the lattice model approach is a valid tool for describing these kinds of flows. Copyright (c) 2007 John Wiley & Sons, Ltd.