This study tracked the episodic motion of coarse sediment cobbles over 2 years to unravel how floods in mountain rivers move sediment. Despite large fluctuations in river discharge and natural variability in climate and topography, observed sediment dynamics agree well with theory and small-scale laboratory experiments; results demonstrate that sediment particle motion can be predicted from a record of river flow depth, providing a direct link between climate and sediment transport.

The paper deals with the measurement of coarse gravel transport in rivers and coastal environments. Quantifying this bedload is generally challenging. The approach adopted here is to use the acoustic sediment-generated noise, SGN, radiated from the interparticle collisions of the mobile bed material. A theoretical model of the radiated sound due to the collisions is presented, and the results are related to the application of SGN to the measurement of bedload transport and mobile particle size.