Offshore sand extraction

Background and objectives

Sand extraction is a striking example of a continuously increasing activity in the shelf sea. The effects of such a large-scale intervention on the morphodynamics of the seabed are difficult to predict. In particular, a sandpit is likely to interact with the complex dynamics of rhythmic patterns (tidal sandbanks, sandwaves), prominently present in the North Sea.

In this project, we have developed and extended idealized, process-based morphodynamic models, on the spatial scales of tidal sandbanks and sandwaves, and for different initial states (flat bed, bank in equilibrium). The results indicate what will happen to the pit itself (deformation, migration), its surroundings (expanding influence area) and the qualitative properties of the overall system (stability, instability). The project contributes to civil engineering/geophysics, but also to developments in marine management.

Publications

Roos, P.C., Hulscher, S.J.M.H., Knaapen, M.A.F. & Van Damme, R.M.J, The cross-sectional shape of tidal sandbanks: Modeling and observations, accepted by J. Geophys. Res., 2004.

Roos, P.C. & Hulscher, S.J.M.H. Large-scale seabed dynamics in offshore morphology: modeling human intervention, Rev. Geophys. 41 (2), 1010, doi:10.1029/2002RG000120, 2003.

Roos, P.C., Blondeaux, P., Hulscher, S.J.M.H., Vittori, G., Sandwave formation triggered by a dredged trench or pit, accepted for presentation at Int. Conf. Coastal Eng., Lisbon, Portugal, September 2004. [ICCE]

Roos, P.C., Hulscher, S.J.M.H., Modelling the morphodynamic effects of different design options for offshore sandpits, accepted for poster presentation at MARID conference, University of Twente, April 2004. [MARID]