Eberhard Renger, Hans-Werner Partenscky


The contribution deals with the morphologic examinations and calculations for a deep-water harbour which is to be constructed in the tidal flats of the Elbe estuary near the North Sea islands of Scharhorn and Neuwerk. An attempt is made to examine the stability of tidal channels (gullies)and tidal flats which may be disturbed to a greater or lesser extent by the various proposals for the connecting dike between the industrial area near the harbour and the coastline. The underlying logic for the determination of the equilibrium of the flats and the quantitative solution for the sand-balance is as follows: It has been shown in several empirical investigations that the increase of the relative volume of the tidal basin (V/VM ), referenced to the gully volume for MLW, can be determined as a simple function to the base (a)logarithm of the geodetic elevation (z*) between MLW and any higher contour level up to MHW. Furthermore it can be shown that (VMT ) is also a function of the tidal drainage area (E). The base(a)has been related to the size of the tidal drainage area (E), because this area is subject to considerable modification by offshore structures such as dikes and causeways.


tidal basin; basin stability; stability criteria

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