A two-dimensional, time-dependent model of suspended sediment transport and bed reworking for continental shelves

Computers & Geosciences
By:  and 

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Abstract

A two-dimensional, time-dependent solution to the transport equation is formulated to account for advection and diffusion of sediment suspended in the bottom boundary layer of continental shelves. This model utilizes a semi-implicit, upwind-differencing scheme to solve the advection-diffusion equation across a two-dimensional transect that is configured so that one dimension is the vertical, and the other is a horizontal dimension usually aligned perpendicular to shelf bathymetry. The model calculates suspended sediment concentration and flux; and requires as input wave properties, current velocities, sediment size distributions, and hydrodynamic sediment properties. From the calculated two-dimensional suspended sediment fluxes, we quantify the redistribution of shelf sediment, bed erosion, and deposition for several sediment sizes during resuspension events. The two-dimensional, time-dependent approach directly accounts for cross-shelf gradients in bed shear stress and sediment properties, as well as transport that occurs before steady-state suspended sediment concentrations have been attained. By including the vertical dimension in the calculations, we avoid depth-averaging suspended sediment concentrations and fluxes, and directly account for differences in transport rates and directions for fine and coarse sediment in the bottom boundary layer. A flux condition is used as the bottom boundary condition for the transport equation in order to capture time-dependence of the suspended sediment field. Model calculations demonstrate the significance of both time-dependent and spatial terms on transport and depositional patterns on continental shelves. ?? 2001 Elsevier Science Ltd. All rights reserved.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title A two-dimensional, time-dependent model of suspended sediment transport and bed reworking for continental shelves
Series title Computers & Geosciences
DOI 10.1016/S0098-3004(00)00122-9
Volume 27
Issue 6
Year Published 2001
Language English
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Computers and Geosciences
First page 675
Last page 690