Bed load transport in gravel streams during floods

Traditionally, bed load transport processes are examined in a simplistic manner, as if they occur under steady state flow conditions. Considering that the vast majority of bed material is transported during unsteady flows, floods, such an approach needs to be re-examined. One set of bed load data from a perennial and another one from an ephemeral gravel bed streams are analyzed here to gain a better understanding of this phenomenon. The results show that the pavement layer controls the release of the bed material and thus greatly influences the transport rates during the passage of a flood. This effect needs to be taken into consideration in future efforts designed to improve the modeling of bed load transport processes. Copyright ASCE 2004.