Changes in basin geomorphology after implementation of the Oosterschelde estuary project

• Published in: Hydrobiologia 1994-05, Vol.282-283 (1), p.29-39
• Main Authors: Mulder, Jan P. M., Louters, Teunis
• Format: Article
• Language: English
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/BF00024619

With the completion of an engineering project in the Oosterschelde estuary, Netherlands, marked changes have occurred in the geomorphology of the ecosystem. Tidal and wave characteristics of the basin have been studied, using data collected over the past decade at a number of fixed sites. Based on an analysis of historical morphodynamic parameters, it can be seen that the Oosterschelde has been an eroding basin for centuries, with erosion amounting to approximately 350 million m super(3) over the period 1872-1952. At the same time, a sediment surplus has been observed at the basin's outer delta. With the construction of a storm-surge barrier and landward dams, tidal current velocities and the tidal range inside the basin have gradually decreased. Channel erosion is now observed only locally, but sandy shoals and mud flats throughout the basin show a distinct erosion trend over the period 1983-90. Since completion of the project, fine sediments have been found to contribute significantly to the sedimentation need of the channels. Ultimately, the establishment of a new morphodynamic equilibrium in the basin will take centuries.