Bedload Transport by Translation Waves

The response of a gravel bed reach to imposed steady flows and to gradually varying triangular translation waves is examined, firstly, under equilibrium transport conditions and, secondly, with no bedload inflow. With equilibrium transport no significant differences could be found between the sediment hydrograph associated with a wave and the comparable steady state sediment hydrograph. This result, combined with the observed but small variation in resistance implies that the use of steady state resistance and bedload formulae in a mathematical model of the situation can be justified. With nonequilibrium transport differences occurred between measured nonsteady sediment hydrographs and the comparable steady hydrographs due to a bed response effect. This diminished towards the downstream end of the scour region associated with a wave's passage. Consequently mathematical model performance would be poor when the reach length is less than the scour hole length.