River systems play a critical role in shaping the landscape and regulating sediment flux from high mountains to lowland basins. In a state of equilibrium, rivers flush out all the sediment generated in headwater and on the hillslopes. However, in a tectonic and climatically dynamic region, out- of-equilibrium conditions results in the transient storage of sediments enroute to the final depocenter. Sediment gets temporarily stored in alluvial fans, floodplains, landslide deposits, river- dammed lakes, and terraces-creating complex feedback between sediment dynamics and changes in internal (e.g. drainage basin size, lithology) and external (climate change, anthropogenic pressures) forces. This session invites contributions exploring the spatial and temporal sediment erosion, transportation and storage along the valley cascade, and shed light on the surface processes, geomorphic responses, paleoenvironment interpretation and landscape evolution in high mountains, over Quaternary timescale.