A general formula for noncohesive suspended sediment transport

A simple and robust suspended load transport formula for noncohesive sediment is presented for application to river, estuarine, and coastal environments with the use of depth-averaged models. The formula is based on an exponential profile for the concentration and assumes a constant velocity over depth to simplify the calculations. These assumptions were validated with a large data set, including data with a steady current, wave and current interaction, and breaking waves. The formula has two parameters: the mean sediment diffusivity over depth and the bottom reference concentration. The sediment diffusivity is estimated assuming a linear combination of mixing because of breaking waves and the energy dissipation in the bottom boundary layer from the mean current, waves, or both. The bottom reference concentration is a function of the Shields parameter. Overall, the formula developed in this study yields the best agreement with the compiled data set compared with a number of existing formulas for estimating the suspended load.