|Tidal asymmetry and long-term evolution of Holocene tidal basins in The Netherlands: simulation of palaeo-tides in the Schelde estuary|van der Spek, A.J.F. (1997). Tidal asymmetry and long-term evolution of Holocene tidal basins in The Netherlands: simulation of palaeo-tides in the Schelde estuary. Mar. Geol. 141(1-4): 71-90. hdl.handle.net/10.1016/S0025-3227(97)00064-9
In: Marine Geology. Elsevier: Amsterdam. ISSN 0025-3227, more
Holocene; Palaeocurrents; Reconstruction; Sediment transport; Tides; Brackish water; Fresh water
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- van der Spek, A.J.F., more
The evolution of tidal basins greatly depends on the interaction between the tide and basin morphology. This interaction results in deformation of the tidal wave which can change the tidal flow, and thus the sediment transport, at the basin inlet. However, this tidal distortion inside tidal basins is complex and cannot be deduced directly from the basin morphology, especially in the case of large basins. Therefore, the reliability of reconstruction of tide deformation in ancient basins with limited topographical information by using a one-dimensional numerical flow model was studied. Two former, historical situations of the Schelde estuary, 1800 AD and 1650 AD, were chosen as a test case. It is shown that for both situations known information on tidal range and phase of the tidal wave is reproduced reasonably well by the model. Since 1650 the tidal flat surface area in the Schelde estuary was strongly reduced. Simultaneously, the channel depth increased. These changes in basin geometry caused an increase in tidal celerity in the estuary. At the mouth, the maximum ebb current velocity increased relative to the maximum flood velocity. If tidal-current asymmetry at the estuary mouth is considered as a measure for net sand transport into the estuary, the simulations indicate a decrease in net basinward sand transport in reaction to the morphological changes in the estuary.