Paper publication alert

Evidence of Secondary Bedform Controls on River Dune Migration

J. Y. Zomer and A. J. F. Hoitink
doi: https://doi.org/10.1029/2024GL109320

The fourth paper of Judith’s Phd project just got published! Dunes are undulating features that can develop on a sandy river bed. They migrate downstream as a result of sediments moving from the stoss, the upstream facing slope of the dune, to the lee, the downstream slope of the dune. Sometimes, multiple scales of dunes coexist, where trains of small dunes travel over larger dunes. In this study we investigate how two dune scales interact and how they contribute to the downstream transport of bed sediments. This is done based on a series of field campaigns in the River Waal. The results indicate that migrating secondary dunes contribute to the displacement of the host dune, the dune over which they migrating. In some cases, secondary dunes travel over the host dune stoss and disintegrate at the host dune lee, depositing sediment there. In other cases, secondary dunes travel over the full length of the host dune toward the next, downstream dune. In this case, part of the sediments transport linked to the secondary dunes contributes to the downstream displacement of the host dune, and part of the sediments are transported to the next primary dune.