Reconstruction of tidal inlet and channel dimensions in the Frisian Middelzee, a former tidal basin in the Dutch Wadden Sea
van der Spek, A.J.F. (1995). Reconstruction of tidal inlet and channel dimensions in the Frisian Middelzee, a former tidal basin in the Dutch Wadden Sea, in: Flemming, B.W. et al. (Ed.) Tidal Signatures in Modern and Ancient Sediments. Special Publication of the International Association of Sedimentologists, 24: pp. 239-258
In: Flemming, B.W.; Bartholomä, A. (Ed.) (1995). Tidal Signatures in Modern and Ancient Sediments. Special Publication of the International Association of Sedimentologists, 24. Blackwell Science: Oxford. ISBN 0-86542-978-2. 358 pp., meer
In: Special Publication of the International Association of Sedimentologists. Blackwell: Oxford. ISSN 0141-3600; e-ISSN 2054-6610, meer
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| Auteur | | Top |
- van der Spek, A.J.F., meer
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| Abstract |
The Middelzee, a Late Holocene tidal basin in The Netherlands Wadden Sea, was created by marine erosion in the Boome Valley. It reached its maximum extension around AD 1000. The basin was rapidly filled in and supratidal salt marshes were formed which were subsequently secured with dikes. By AD 1600 the landward part of the Middelzee had been reclaimed. This caused partial infilling of the remaining channels in the Wadden Sea and the tidal inlet. The cross-sectional surface area and depth of the tidal channels and tidal inlet were calculated from the basin surface area and the tidal discharge, using empirical relationships derived in this paper as well as published in the literature. The calculations show that, given the maximum thickness of inlet channel deposits, the tidal prism was distributed over two inlet channels until AD 1 700. This is in agreement with historical nautical charts. The calculated maximum channel depths for tidal channels in the Middelzee are in agreement with the channel sediment thicknesses found in borings. Locally, these calculated maximum depths were significantly less than the maximum thickness of the channel deposits. This indicates that Middelzee channels have cut down into channel sediments deposited during earlier transgressions in the Boome Valley. This provides valuable information on the evolution of the tidal basin. The minimum annual sediment import between AD 1000 and AD 1600, estimated from the decrease in basin surface area and the infilling of the channels, is 1,9 x 106 m³. This rate falls well within the range of the estimated present-day sediment input into the Wadden Sea tidal basins. |
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