Estimation of sediment grain sizes in a mesotidal area, Dithmarschen Bight, German North Sea

This article presents a fast and suitable method to derive the spatial distribution of seabed grain sizes on tidal flats. A successful validation was carried out in the Dithmarschen Bight, a meso-tidal area of the German North Sea coast. In particular, the study is built on statistical correlations between observations of sediment sizes from 197 seabed samples and the numerical model output of flow-wave variables under specific marine and atmospheric forcings. The correlation between orbital velocities and mean grain sizes (d50) exhibited the best results, but it can be affected under low relative wave height ratios. The methodology was applied for the construction of a high-resolution map of grain sizes in the Dithmarschen Bight, which resulted in absolute and relative errors of 16 µm and 13%, respectively. The proposed relationship was also adopted to examine scenarios of field data scarcity. © 201