Experimental and numerical simulation of bed load transport over steep slopes

Mathematical models used to describe sediment transport are updated to include more physical characteristics resulting in more accurate numerical predictions. Hence, the present work studies the influence of gravity effects in the bed load transport over steep sloping beds. For this purpose the 2D gravity projections on global coordinates have been included not only in the sediment fluxes, which is the classical approach, but also in the water fluxes and in the pressure/friction terms. Additionally, a set of experiments involving steep slopes has been designed and carried out. Comparisons between the numerical and the experimental results are reported. The gravity projections included in the hydrodynamic and morphodynamic models lead to more accurate predictions in two situations: (i) at the initial stages of experiments where the bed slopes angles are higher; and (ii) under large water and solid discharges, where the interaction between the bed and the water is stronger.