Evaluating secondary flows in the evolution of sine-generated meanders

The development of meanders has been the focus of research for decades because the shifting of bank lines may potentially cause serious problems in river engineering. This study assesses the roles of secondary flows in meander evolution by testing two model parameters, A and As, which represent the effects of momentum redistribution exerted by the topography-driven and curvature-driven secondary currents, respectively. The meander-evolution model couples an analytical solution of flow field in a sine-generated channel with the Bank Erosion and Retreat Model (BERM). The contributions of this study lie in two areas. First, the authors isolated and quantified the roles of curvature-driven and topography-driven secondary flows in meander evolution. Second, the shifting processes of primary flow by secondary flows were investigated in detail by evaluating various variations of the dimensionless scour factor A.