The morphology of the sand dunes changes noticeably across the sand bank. The sequence is as follows: low, two‐dimensional dunes, increasing in wavelength, height, sinuosity and asymmetry to form three‐dimensional dunes on the thickest and shallowest part of the bank are replaced by dunes with lee‐side scours becoming more prevalent and the formation of lunate megaripples along the landward edge and off the tip of the sand bank. These visual changes, together with measurements of lee‐slope volume deficits, suggest that the bedforms change in response to decreasing cohesion, increasing peak bottom stress and eventually decreasing volume of available bedload as the effect of dune crest localized suspension increases.
