Modelling the morphodynamic impact of offshore sandpit geometries

We investigate the hydrodynamic effects and morphodynamic impact of large-scale offshore sand extraction, for a variety of pit designs. We use a process-based idealized model for flow, sediment transport and bed evolution in a tide-dominated environment. Legislation and other practical considerations motivate our assumption that sandpits are both wide (horizontal dimensions of the order of kilometres) and shallow (the ratio of pit depth to water depth being small). This results in a semi-analytical tool that, unlike previous studies, enables a quick and extensive study into the effects of varying the physical characteristics as well as the pit design parameters. These parameters include pit length, width, and orientation with respect to the tide.