Particle size variations between bed load and bed material in natural gravel bed channels

Abstract

Abstract - Particle sizes of bed load and bed material that represent materials transported and stored over a period of years are used to investigate selective transport in 13 previously sampled, natural gravel bed channels. The ratio (D*) of median particle size of bed material to the transport- and frequency-weighted mean of median bed load size decreases to unity with increasing drainage area, bank-full discharge, dimensionless stream power, and bed material sorting. In channels with high values of D*, significant volumes of fine bed load are transported during discharges that are less than bank-full, which is commonly associated with general entrainment of the coarse pavement in many gravel bed channels. This indicates transport of fine bed load over a more stable substrate of coarser bed material.

Keywords

PSW4351, bed load, bed material, particle size, gravel bed channels, sediment, subsurface

Citation

Lisle, Thomas E. 1995. Particle size variations between bed load and bed material in natural gravel bed channels. Water Resources Research 31(4): 1107-1118.