New approach to understanding sediment transport



Sediment transport is an important factor in the evolution of river channels. Bed load sediment flux, defined as the volume of particles crossing a vertical surface per unit time per unit width, is a common way to describe sediment transport. However, quantifying bed load sediment flux in terms of conceptually simple quantities is challenging, as the motion of particles in turbulent water is very complex. In a set of four related papers, Furbish et al. developed a new probabilistic definition of bed load transport and verified their approach using laboratory experiments and model simulations. Their approach, which treats particle positions and motions as stochastic quantities, shows how the particle activity and velocity distributions are key elements in describing sediment flux. Their experiments, using high-speed imaging of sand particle motions in a laboratory tank, allowed them to directly observe particle behavior and test their theory. Model simulations also verified their approach. (Journal of Geophysical Research-Earth Surface, doi:10.1029/2012JF002352, 2012, doi:10.1029/2012JF002353, 2012, doi:10.1029/2012JF002355, 2012, and doi:10.1029/2012JF002356, 2012)