Tidal sand ridges on the shelf: A numerical study of their natural morphodynamic evolution and response to interventions

摘要

Tidal sand ridges are large-scale bottom features that occur on continental shelves with strong tidal currents and abundance of sand. These ridges have longshore spacings of several kilometres, heights of tens of metres, they evolve on centennial time scales and their crests are cyclonically rotated with respect to the direction of the dominant tidal currents. The coupled Delft3D-SWAN numerical model is used to study the natural morphodynamic evolution of tidal sand ridges and their response to interventions (sand extraction and construction of islands) in a setting that resembles the Belgian shelf. New aspects in this study are that a sophisticated wave model (SWAN), a shelf with a sloping bottom and state-of-the-art formulations for sediment transport (including suspended load) are considered.