Abstract
Laboratory flume
experiments of shallow overland flow show that the sediment transport is not a
random phenomenon but occurs in a highly organized manner. The organization
reveals evolution of bed covered by sediments with several scales ranging from saltation of particles at very low concentrations to
movement in wave forms. The wave modes emerge in post-saltation
state and the sediment transport capacity of shallow flows is severely
impacted. These wave modes consist of stripes, meanders and alternate bars. The
temporal evolution of transport rates in the equilibrium stripe mode indicates
smaller time scales (~ 10 sec) compared to (~10 min) the large spatial scale
structures such as meanders. Power spectra of transport rate fluctuations characterize
the stripe mode with multiple peaks at different frequencies.
Keywords: Shallow