This research developed a two-dimensional, time-dependent numerical model to simulate the movement of water and suspended sediment in the turbidity maximum of an estuary. This model is a systematic sequence of mathematical procedures derived from the mass-balance equation and the equation of motion. Lateral integration is used to obtain two-dimensional equations; these equations are integrated with depth over the height of successive layers. Finite difference equations then are written for each layer and solved numerically using prescribed boundary conditions.

The model yields values for time-varying tidal height, current speed, salinity, and suspended sediment concentration (turbidity) throughout the estuary. In turn, these variations reveal the response to tidal current fluctuations of both salinity and sediment distributions within the maximum. Residual values of each parameter are obtained by averaging respective values over a tidal cycle. By examining the time-varying and the tidal average transport at landward and seaward transects, sediment transport through the turbidity maximum may be studied in detail. Using this numerical model permits analyses of hydraulic processes that lead to suspended sediment accumulation.