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.

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.