Numerical Modelling of Beach Profile Dynamics for Very Shallow Foreshores

The performed research is situated within the fundamental strategic research project CREST- Climate Resilient coast, funded by Strategic Basic Research (SBO) program of the Flanders Innovation & Entrepreneurship (previously lead by IWT ).

The main objective of the CREST project is to gain a better understanding of the nearshore and onshore physical processes and flood risks and to determine the most appropriate way with the possible impact of climate change. The Belgian coast has a very specific cross-section, consisting of a very shallow foreshore followed by a hard dike, a promenade and a storm wall and an almost continuous line of buildings. In the design of storm defence measures (e.g. storm walls), the necessary height is calculated based on an allowed overtopping volume. Current state of the art methodologies to calculate wave overtopping, are based on empirical formulae which are too conservative for the typical Belgian cross-section. In addition, the design criterion for wave overtopping focusses on mean discharge. Individual overtopping volumes have not been investigated into much detail yet, but seem a more critical design parameter. Further research is needed to improve our current knowledge and implement it in applications for the Belgian coastline.

My PhD research focusses on the wave resolving numerical modelling of hydrodynamics interacting with the beach and hard coastal defence systems. In a first phase the changing beach morphodynamics on very shallow foreshores and the resulting effect on wave overtopping volumes and wave impact forces on coastal structures are studied.

The aim is to incorporate within the same code the effects of sediment transport to study the loss of energy by mobilized sediments and changing morphodynamics of the beach before waves reach the dike and hence study the influence on wave loading forces and overtopping volumes.