|Interestuarine comparison: hydrogeomorphology: hydro- and geomorphodynamics of the TIDE estuaries Scheldt, Elbe, Weser and Humber|
Vandenbruwaene, W.; Plancke, Y.; Verwaest, T.; Mostaert, F. (2013). Interestuarine comparison: hydrogeomorphology: hydro- and geomorphodynamics of the TIDE estuaries Scheldt, Elbe, Weser and Humber. Version 4.0. WL Rapporten, 770_62b. Flanders Hydraulics Research: Antwerp. 70 + 14 p. appendices pp.
Deel van: WL Rapporten. Waterbouwkundig Laboratorium: Antwerpen. , meer
Earth sciences > Geology > Geomorphology
Hydraulics and sediment > Hydrodynamics > River flow
Hydraulics and sediment > Hydrodynamics > Tides
Hydraulics and sediment > Morphology > Erosion / sedimentation
Hydraulics and sediment > Morphology > Habitats
Hydraulics and sediment > Morphology > Intertidal zones
Hydraulics and sediment > Sediment > Cohesive sediment
Literature and desktop study
Physics > Mechanics > Fluid mechanics > Hydrodynamics
Water bodies > Coastal waters > Coastal landforms > Coastal inlets > Estuaries
: Gemeentelijk Havenbedrijf Antwerpen (GHA), meer
Within the scope of the INTERREG IVb project TIDE (TIdal river DEvelopment), an interestuarine comparison of 4 partner estuaries (Scheldt, Elbe, Weser and Humber) was performed. Different aspects of the estuaries were handled within the interestuarine comparision: hydrodynamics, geomorphology, ecology, birds, historical changes and monitoring. This study reports on the hydro- and geomorphodynamics of the TIDE estuaries.
Five research topics were handled within the hydro-geomorphology study: (1) tidal damping/amplification, (2) relation between habitats and the tide, (3) suspended sediments, (4) residence times, and (5) tidal marshes. For each topic a number of specific research questions were listed (see §2). To be able to answer these questions several main parameters (i.e. Directly measured in the estuary) were collected (topo-bathymetry data, tide, salinity, SPM, freshwater discharges and tidal marsh data). Furthermore some additional parameters were derived (e.g., flow velocities, tidal energy, tidal damping scale) using some specific techniques (e.g., cubage technique, Dalrymple energy concept).
We found that tidal damping in an estuary becomes important once the estuary depth (i.e. Cross-section averaged depth at low water) becomes lower than 4.2 – 7.7 m, depending on the estuary-convergence. Similar results were found for the habitat analysis: once the area of the deep subtidal habitat (> 5 m below low water) becomes smaller than 20 %, and the area of the shallow subtidal habitat (< 5 m below low water) becomes larger than 35 %, tidal damping in an estuary prevails. Concerning SPM, turbidity maxima are associated with maxima in tidal energy. We further found that these high SPM values force tidal marshes to faster attain a high climax vegetation state with less plant diversity.