Evaluation of Bed Load in a Gravel-Bed River

Abstract

Bed load transport is needed for river training works, reservoir management, watershed management, and ecosystem maintenance. A number of equations have been developed for determining bed load transport, primarily for alluvial rivers. This study applies the boundary-layer characteristics to evaluate bed shear stress and the rate of bed load. Also, seven bed load equations are evaluated by using field measurements from twelve cross-sections in three reaches of Babolroud River in northern Iran. It is found that only the equations of Duboys (1879), Hasanzadeh (1995) and Recking (2013) predict bed load reasonably when compared with observed bed load values. The bed load is about 2.70% of the suspended sediment load which is less than what is generally reported in the literature. The sediment rating curve developed using sediment discharge and water discharge relationship for all available data from four hydrometric stations produce satisfactory results.