Saw-tooth bar dynamics on the Ameland ebb-tidal delta

Abstract

Ebb-tidal deltas are part of tidal inlet systems, and it is important to understand sediment transport processes and pathways that take place there. Sediment is transported along ebb-tidal deltas as both suspended load and bedload, and bedform migration is one of the processes by which bedload transport can take place. Saw-tooth bars are bedforms that are found regularly on ebb-tidal deltas, but they have not been studied thoroughly yet. The present study shows the characteristics of these bars, like bar height and length. Spatial correlation was used to find their migration speed. It was found that saw-tooth bars are approximately 2m high and have a wavelength of 500-1000m. Both bar height and migration speed appear to change in a cyclic way. The saw-tooth bars contribute substantially to the total sediment transport on the ebb-tidal delta.