Abstract.
The most severe storm passing Denmark in the 20th century occurred on 3–4 December 1999. During this event, waves, currents and suspended sediment concentrations were measured on a muddy tidal flat vis-à-vis the salt marsh of Skallingen in the inner part of the Hobo Dyb tidal area on the Danish west coast. Locally generated wave heights increased during the storm to Hs=0.38 m, with peak spectral wave periods of up to 3.6 s and wave-induced bed shear stresses reaching a maximum of about 2 N m–2. The highest current velocity measured over the tidal flat during the surge was 0.64 m s–1 (~1 N m–2). During the surge peak, the wind-induced water circulation close to the bed was about 0.2 m s–1 which is equivalent to a bed shear stress of about 0.2 N m–2. The concentration of suspended matter on the tidal flat increased from about 10 mg l–1 to about 200 mg l–1, and the mobile layer on the mud flat was removed. The estimated deposition on the salt marsh amounted to 133 g m–2 (0.15 mm) which is only about 50% higher than that of a previously monitored gale event, and corresponds to less than 10% of the yearly deposition at the site.
It is suggested that deposition on the salt-marsh surface caused by storms or gales depends on the prevailing meteorological and hydrographical conditions as well as on the sequence of previous import and high-energy events. The results indicate that a single extreme storm can be of less importance for annual variations in salt-marsh deposition than more regularly occurring gales.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bartholdy, J., Aagaard, T. Storm surge effects on a back-barrier tidal flat of the Danish Wadden Sea. Geo-Mar Lett 20, 133–141 (2001). https://doi.org/10.1007/s003670000048
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/s003670000048