Gravitational effects on river morphodynamics

In the present work an experimental study devoted to investigate the effects of transversal slopes on the bedload sediment transport and on the morphodynamic evolution of a mobile bed was carried out. The general aim of such investigation is the experimental observation of the evolution of a laterally tilted bed from the initial configuration to the final one, laterally flat, under conditions of uniform flow. The bottom topography was measured at the beginning and during the experiments for different time lengths; complementary data regarding the applied shear stresses and the particle velocity are inferred from a previous experimental activity on bedload transport over an non-erodible bed. The experimental results about the evolution of the bed were interpreted theoretically by solving numerically the 3-D governing morphodynamic problem employing the non linear theoretical model for bedload transport over sloping beds proposed by Parker, Seminara and Solari (2003). The experimental observations are compared to the results obtained from the numerical model in terms of the evolution of the bed topography, applied shear stress and sediment transport rate in longitudinal and transversal directions. In the present contribution, both experimental and numerical results are presented and discussed.