Understanding more deeply the motion of sediment is of fundamental importance in hydraulic engineering, fluvial geomorphology and in attempting to estimate future landscape evolution over the next decades and centuries. The recent advent of long, high-quality field and experimental data series makes rigorous statistical analysis possible. This session invites contributions from scientists who try to explore the variability of sediment transport based on observations and a full hierarchy of approaches including experimental studies, partial differential equations, fractal, stochastic and cellular automaton models. One of our focus is on the transfer from numerical geosciences, statistical physics and applied mathematics to geomorphology, helping to tackle the physics of sediment transport as well as the evolution of bed forms and channel morphology. Contributions dealing with bedload transport in mountainous streams, sediment transport in river, coastal and aeolian environment are as welcome and heartily invited.