Spatially Varying Environmental Properties Controlling Observed Sand Wave Morphology

Abstract

Sand wave morphology and dynamics on continental shelves vary substantially, and we hypothesize that these spatial variations depend on local bed properties and hydrodynamic characteristics. To date, process‐based modeling studies have not been able to simulate realistic equilibrium sand wave heights and empirical studies are mostly limited to case studies. In order to explain the spatial variation in the morphology of equilibrium sand waves on continental shelves with processes and local bed conditions, a large‐scale investigation is required. In this paper, we use high‐resolution multibeam echo soundings, hydrodynamic models, and databases and sedimentary data for the analysis of, respectively, sand wave shape characteristics and the comparison to hydrodynamic and sedimentary characteristics for the Netherlands Continental Shelf. The results are quantified lengths, heights, and asymmetry of all sand waves in the Dutch part of the North Sea. Furthermore, we show that the mode of sediment transport (bed load or suspended) is a dominant factor in explaining sand wavelength, height, and asymmetry. Full results of shape characteristics of all sand waves on the Netherlands Continental Shelf together with the tidal velocity, water depth, surface wave height, and median grain size are provided in a repository with this paper (http://doi.org/10.4121/uuid:0d7e016d‐2182‐46ea‐bc19‐cdfda5c20308). These results are highly valuable for applied offshore engineering projects and to modelers for validating their morphodynamic model results.