TY - JOUR
T1 - Bedform dynamics and net sediment transport paths over a flood-ebb tidal cycle in the Grådyb channel (Denmark), determined by high-resolution multi-beam echosounding
AU - Bartholomä, Alexander
AU - Ernstsen, Verner B.
AU - Flemming, Burg W.
AU - Bartholdy, Jesper
N1 - Funding Information:
The authors wish to heartily thank the captain and crew of the RV Senckenberg for their help and expertise during the September 2002 cruise period. We are indebted for the international cooperation to the harbour authority of Esbjerg, to the Royal Danish Administration of Navigation and Hydrography (Farvandsvresnet), Copenhagen, and to the Institute of Geography, University of Copenhagen. The referees are acknowledged for their constructive review comments. Finally, the Senckenbergische Naturforschende Gesellschaft and the Research Centre of Ocean Margins, University of Bremen, is thanked for providing the financial assistance to realise this study.
PY - 2004
Y1 - 2004
N2 - High-resolution bathymetric surveys were carried out by means of a high-frequency (455 kHz) multibeam-echosounder (MBES) to determine the total volumetric sediment transport over a tidal period in a tidal channel at the Danish west coast. With the high repetition rate and high accuracy of the MBES, a simple comparison of morphological changes recorded at short time intervals allows an accurate calculation of dune heights and migration rates, the main parameters required for realistic approximations of volume budgets in tidal channels. The net sediment volume of 0.061 m3 per m2 over one tidal period is ebb-orientated, which means an annual net volume export of 44.5 m3 m-2 year-1. The general ebb-oriented export trend recorded for the large, compound dune system is contrasted by a net flood-oriented transport in the 'active zone' involving smaller superimposed dunes, which amounts to 0.6 m2 per flow phase on top of the large dunes, and 0.15 m2 per flow phase on the slopes and in the troughs. This gives a mean volumetric sediment transport rate of 0.7697×105 m2 s-1 for the ebb flow, and 1.059×105 m2 s-1 for the flood flow, strongly deviating from earlier calculated transport rates.
AB - High-resolution bathymetric surveys were carried out by means of a high-frequency (455 kHz) multibeam-echosounder (MBES) to determine the total volumetric sediment transport over a tidal period in a tidal channel at the Danish west coast. With the high repetition rate and high accuracy of the MBES, a simple comparison of morphological changes recorded at short time intervals allows an accurate calculation of dune heights and migration rates, the main parameters required for realistic approximations of volume budgets in tidal channels. The net sediment volume of 0.061 m3 per m2 over one tidal period is ebb-orientated, which means an annual net volume export of 44.5 m3 m-2 year-1. The general ebb-oriented export trend recorded for the large, compound dune system is contrasted by a net flood-oriented transport in the 'active zone' involving smaller superimposed dunes, which amounts to 0.6 m2 per flow phase on top of the large dunes, and 0.15 m2 per flow phase on the slopes and in the troughs. This gives a mean volumetric sediment transport rate of 0.7697×105 m2 s-1 for the ebb flow, and 1.059×105 m2 s-1 for the flood flow, strongly deviating from earlier calculated transport rates.
KW - Bedform dynamics
KW - Grådyb channel (Denmark)
KW - Multibeam echosounding
KW - Sediment transport rates
KW - Tidal cycle
UR - http://www.scopus.com/inward/record.url?scp=4444309065&partnerID=8YFLogxK
U2 - 10.1080/00167223.2004.10649503
DO - 10.1080/00167223.2004.10649503
M3 - Article
AN - SCOPUS:4444309065
SN - 0016-7223
VL - 104
SP - 45
EP - 55
JO - Geografisk Tidsskrift
JF - Geografisk Tidsskrift
IS - 1
ER -