The North Sea is a complex physical system. Water, sediment and the seabed interact according to nonlinear processes that are still only partly understood. These processes continuously affect the shape of the seabed, particularly causing the presence of various large-scale and dynamic seabed patterns: tidal sandbanks and sandwaves.
Besides a fascinating nonlinear system, the North Sea is of huge economical and societal importance. This inevitably leads to conflicts between activities (e.g., sand extraction/navigation dredging) and other interests (e.g., coastal safety). Herein, sandbank and sandwave dynamics are crucial. How these features respond to our intense activities in an environment that simultaneously experiences gradual changes (sea level rise) is unknown. Clearly, our insufficient understanding of large-scale pattern dynamics makes it hard to manage activities in the North Sea.
The proposed research aims at developing morphodynamic modeling tools that provide answers to these exigent questions concerning large-scale seabed patterns versus sea level rise and sand extraction.
The very nature of these issues requires embracing the concept of transient (morpho)dynamics: the North Sea is continuously responding to abrupt and gradual changes in its environment. The project furthermore bridges a methodological gap in the field of morphodynamic modeling. So far, models particularly designed to study pattern dynamics (type A) have not been geared to deal with engineering problems, whereas engineering models (type B) have not been successful in describing pattern dynamics. The project will improve models of type A, in collaboration with modelers from engineering practice (type B, participating in the user group). Capturing nonlinear dynamics is essential; validation will be done using field data available from European projects and governmental agencies.
This project contributes to a sustainable policy regarding sand extraction in the North Sea. Moreover, it enables improvements in survey and dredging strategies that significantly reduce the cost of seabed maintenance.