Understanding 3D sand wave dynamics for engineering purposes

Due to ambitious green energy goals the pressure on the offshore area is increasing at an unprecedented pace. These offshore developments, such as wind farms, require detailed bed level predictions. However, the uncertainty in these predictions increases dramatically when dynamic bed forms, such as sand waves, are present. This is the case in many areas, such as the North Sea, Taiwan Strait and the Banks Strait Australia. Sand waves can grow up to 25 percent of the water depth, have wavelengths of hundreds of meters and migrate with several meters per year. Due to their dynamic nature and size they may pose a threat to offshore activities, such as the construction and maintenance of wind farms and ship navigation. Cables and pipelines may become exposed and foundation could become unstable, due to the migration and/or shape changes of sand waves. Currently data-driven methods are applied to predict future bed levels. The use of process-based numerical models could improve the accuracy of these predictions and help quantifying uncertainties over time. Additionally, these models give insight into the effects of extreme events and human interventions, and provide a solution for data-scarce areas.