A major proportion of the sediments deposited in the Dutch coastal zone during the Holocene transgression originated from the Souther North Sea. Recent research has shown that the seabed of the souther Bight has been profoundly reworked and that large amounts of sediment have been transported, partly in coastal direction. These long-term, large-scale morphodynamics are closely related to sea level rise. The forces driving large-scale morphodynamics are produced by tides and meteorological influences, and thus act on a much smaller time scale. The same forces also generate a variety of morphological structures on much smaller scales. These include sandbanks, sand waves and ripples. The current and transport patterns on the shelf that generate morphological change are in turn themselves influenced by these morphological structures. This feedback results both from large and smaller-scale structures. The seabed behaves, therefore, as a cascade system with self-organizing properties.

Research activities on the theme of Seabed and Shelf comprise sediment transport dynamics, numerical morphodynamic modelling, morphodynamic analysis of finite amplitude perturbations on the sea bottom using idealized models, and mapping of both the top layer and the deeper sediment layers of the sea floor. The resultant understandings are relevant to many practical issues. These include: improving the stability of navigation channels, locating sand mining pits, preventing destruction of cables and conduits on the sea floor, optimizing sea-floor monitoring programmes, predicting coastal response to sea level rise on geological time scales, and the construction of artificial islands.