Bank Erosion in Meandering Rivers

In the present paper, two different models of bank erosion are analyzed. The first model consists of a linear relation between bank erosion rate and near-bank excess velocity that is used by most planform evolution models. The second formulation is a bank failure model that consider in more detail the dynamics of bank erosion, but has been applied mainly for the case of straight reaches. Using the bank failure model, an analytical expression for the erosion coefficient is obtained, which depends explicitly on resistive properties of the banks, on the near bank perturbation velocity and on the streamwise cross sectional averaged velocity. The present analysis also considers bank retreat as a stepwise phenomenon triggered by a critical value of the localized erosion.