BED-LOAD AND SUSPENDED-LOAD TRANSPORT OF NONUNIFORM SEDIMENTS

Methods are available for the computation of the bed-load and suspended-load transport rates of uniform sediments. However, limited studies exist for nonuniform sediments. These studies, in general, lack simplicity, and often make use of various correction factors to be read from a series of tables and graphs. This not only makes the evaluation cumbersome, but results in loss of accuracy at each stage. In this paper, useful empirical equations for the bed-load and suspended-load transport rates of nonuniform sediments are developed. As a special case, these equations faithfully describe the transport relations for uniform sediments. The nonuniformity of sediments is described by an empirical three-parameter grain-size distribution equation for unimodal shapes. A link between parameters of lognormal size distribution and the proposed size distribution is established. The proposed empirical equations for the bed-load and suspended-load transport rates of nonuniform sediments are also useful for total-load transport rate computation.