The lack of
observation data on sediment runoff has resulted in developing a number of formulae
for the runoff calculation. The formulae are valid only for a limited range of
determining factors and are not reliable enough. For low-land rivers, the main sediment runoff and channel formation takes
place during a flooding season. The complicating factor here is an effect of
channel and flood-plain interaction that leads to essential transformation of
velocity fields in the flows. Estimates of the channel flow effect on sediment
transport are growing rapidly as water level rises and are going down as the
level falls. That is the essence of self-regulation process in the flaw-channel
system.
During the flooding
period, large channel formations and motions take place as well. As the water
level falls and the acting forces reduce their magnitude, the motions of the
formations comes to a halt and ground ridges of the lesser size start shifting
on the head slopes. As the water level continues to fall the process repeats
itself. That results in forming a hierarchy of 7-10 ridges.
Keywords: River, bed load, flood,
experiments, floodplain, streams, velocities, processes, channel