Sediment transport in the presence of large reef bottom roughness

A study at Ningaloo Reef, Western Australia, reveals that large bottom roughness—such as reef structures and benthic organisms—significantly alters sediment transport dynamics. Traditional models overestimate the shear stress required to suspend coarse sediments due to reduced near-bed flow in rough environments. By accounting for this roughness-induced flow reduction, researchers improved predictions of suspended grain sizes, demonstrating that ignoring these effects leads to inaccurate sediment transport estimates. The findings highlight the need to incorporate roughness impacts on both overlying flow and bed stresses in shallow coastal ecosystems, where such features are common.

Pomeroy, A. W. M., Lowe, R. J., Ghisalberti, M., Storlazzi, C., Symonds, G., & Roelvink, D. (2017). Sediment transport in the presence of large reef bottom roughness. Journal of Geophysical Research: Oceans, 122(2), 1347–1368. Portico. https://doi.org/10.1002/2016jc011755