Modelling Finite-Amplitude Sand Wave Dynamics:The Role of Cohesive Sediment

Increased marine sand extraction volumes require a better understanding of the interactions among the extraction pit, bed forms and environmental conditions such as the local flow and sediment properties. Sand wave dynamics is particularly relevant, as these are features with a wavelength (of hundreds of meters) comparable to typical extraction pit dimensions, and are active on engineering timescales of years to decades. Additionally, sand extraction pits generally contain increased amounts of cohesive sediment, due to the lower<br/>hydrodynamic activity. So far, sand wave model studies have only considered non-cohesive sediment, whereas field observations suggest that the impact of cohesive sediment on sand wave occurrence might be profound (Hulscher &amp; Van Den Brink, 2001). However, it is unclear what processes exactly cause reduced sand wave occurrence in regions with more cohesive sediment. In this study,<br/>we therefore explore the interaction between cohesive sediment and sand wave dynamics.