Coupled estimation of the energy slope and associated sand-silt transport during high stream power events in alluvial rivers

A coupled routing for the transport capacity and the energy slope is introduced through the definition of the control factor m whose value is linked to the bed form configuration. The coupling aims to further incorporate the interactions occurring in alluvial rivers and thus enhance the prediction of the fine sediment fluxes, especially during high stream power events. Based on a predictive rule for the control factor m that only involves water depth, velocity and bedform constitutive texture, the novel method is confronted to observations collected in one of the most strongly dynamic alluvial river namely the Lower Yellow River. Comparisons between time series of measured and computed concentrations illustrate that during high velocity events the main dynamics of the sediment transport is correctly reproduced. The main advantage of the present approach is to supply consistent time evolutions of sediment concentrations without making use of any detailed shear information.