Avalanching of the dune face

Avalanching of the dune face: field observations and equilibrium theory

van Wiechen, P.P.J. (TU Delft Coastal Engineering)
Rutten, J. (TU Delft Environmental Fluid Mechanics)
Mieras, Ryan (University of North Carolina Wilmington)
Anarde, Katherine (North Carolina State University)
Tissier, M.F.S. (TU Delft Environmental Fluid Mechanics)
de Vries, S. (TU Delft Coastal Engineering)

Wang, Ping (editor)
Royer, Elizabeth (editor)
Rosati, Julie D. (editor)

2023

A field experiment to study dune erosion was conducted on the Sand Engine near Kijkduin, the Netherlands, from November 7th 2021 to January 7th 2022. Two artificial unvegetated dunes were constructed near the high water line, and experienced significant erosion through avalanching during three storms. This paper aims to identify what drives dune erosion through avalanching by using the collected data and equilibrium theory. Results suggest that the cumulative volume eroded through avalanching during a single high water is positively correlated with the profile mismatch between the pre-storm profile and a ‘storm equilibrium profile’, described by a 2/3rd power law, an empirical coefficient A, and the total water level. This mismatch is quantified by calculating the area integral of the profile that is acquired when the upper 35 m of the pre-storm profile is subtracted from the upper 35 m of the equilibrium profile. Avalanching commences when this mismatch becomes larger than approximately 0, after which 1 m3/m of sediment erodes from the dune face for every 3 m3/m mismatch. In addition, during one event avalanching occurred even though the elevation of the total water level did not exceed the initial elevation of the dune toe. This implies that a total water level that exceeds the initial elevation of the dune toe is not a requisite for avalanching and a collision regime to occur, which contradicts conventional definitions of dune erosion regimes. These results have implications on risk assessment of storm conditions on dune erosion.

http://resolver.tudelft.nl/uuid:e7780a44-a74f-4ec6-b975-c966e6af32b1

https://doi.org/10.1142/9789811275135_0069

World Scientific Publishing

2023-10-15

978-981-12-7989-8

Coastal Sediments 2023

Coastal Sediments 2023, 2023-04-11 → 2023-04-15, New Orleans, United States

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

conference paper

© 2023 P.P.J. van Wiechen, J. Rutten, Ryan Mieras, Katherine Anarde, M.F.S. Tissier, S. de Vries