Detection and quantification of sediment remobilization processes using a dynamic penetrometer

Sediment remobilization processes have a high impact on coastal morphology as well as offshore engineering. In many cases countermeasures are required to preserve the stability of the construction or coastline. To apply such countermeasures in the most effective manner, it is crucial to (i) locate and map areas of sediment erosion and deposition and to (ii) quantify the mobilized sediment with a high spatial and temporal resolution. In this study we tested the small dynamic penetrometer Nimrod as a tool for rapid detection and quantification of sediment remobilization processes. More than 20 surveys with about 5000 deployments covered natural-induced sediment remobilization processes such as shifting sandbars and sorted bedforms as well as man-induced processes such as the siltation in navigation channels and scour. The surveys were carried out in areas of different sediment textures ranging from soft clay to hard quartz and carbonate sands. Additionally, preliminary experiments under controlled boundary conditions were accomplished in a wave channel (Franzius Institut, Hannover, Germany).