Monitoring the sand extraction on the Belgian Continental Shelf: methodology, results and expectations

Within the framework of a sustainable exploitation of the mineral resources on the Belgian Continental Shelf, the Belgian government has established a surveillance and monitoring program of the extraction activities and the impact on the environment. The up to date results show a concentration of the activities on the Kwintebank, resulting in a strong but merely local impact of the extractions on the bathymetry and sediments of the seafloor. In the near future the governmental control will evolve to a real-time surveillance and a dynamic and three-dimensional monitoring program to assure the future sustainability of the economically important exploitation of mineral resources

Ripple filtering and ridge enhancement applied to morphodynamical tracking of sand dunes

International audienceA 3D global semi-automatic approach based on bathymetric triangulated irregular network (TIN) is developed to extract the overall sand dunes pattern inside a given area. This method takes advantage of a new purpose-built anisotropic filter able to enhance the dominant features of the bathymetric mesh surfaces while smoothing out their ripples. The salient ridge and valley lines of the sand dunes are automatically extracted as 3D parametric curves trough a saliency indicator. This new approach is tested on a fourteen years long time series of thirty MBES bathymetric datasets acquired by the Continental Shelf Service of the FPS Economy of Belgium on a monitoring area located on the northern part of the Middelkerke bank (Flemish banks, Belgian part of the North Sea). Based on the 3D vectors resulting from this approach, 3D augmented representation can right now assist geoscientists in tracking dunes morphology and dynamic but calculation methods should be specifically developed to assess the magnitude and direction of the dunes movement and evaluate the volume of sand involved in the dune dynamics