Bed morphology in Kinoshita meandering channels: Experiments and numerical simulations

Meandering rivers evolve and interact with floodplains constantly. During this evolution, several hydrodynamic (primary and secondary velocities and turbulence flowstructure distribution) and morphodynamic features are presented (double heading bends, symmetric and asymmetric bends, upstream- and downstreamvaller oriented bends).The detailed study of several of these stages is necessary to understand howrivers migrate. In the past, several experimental studies and analytical formulations were performed mostly in symmetric lowsinuosity meandering channels. In this study, a high-sinuosity asymmetric meandering channel, "the Kinoshita channel" was built at the Ven Te Chow Hydrosystems Laboratory. The channel was designed to keep high harmonic modes on the planform configuration, which differentiates it from a purely sine-generated meandering channel. In this regard, the channel could have the meander bends oriented upstream- and downstream-valley (skewed) by switching the water and sediment flow directions. Abad et al.(2007) perfomed several flat bed smooth experiments under both bend orientations, showing that the 3D mean and turbulence flow structure are unique for each bend orientation; therefore, inferring that hydrodynamics will influence the morphological patterns. In this study, mobile bed conditions are studied by performing experiments in the "Kinoshita channel" and prediction of morphology is done by using a 2D depth averaged model previously validated (Abad et al. 2007).