Erosion on Isle of Palms due to shoal bypassing

Abstract

At Isle of Palms there is a lot of erosion due to shoal bypassing events. Five TU Delft Hydraulic Engineering students went to the island under supervision of Coastal Science and Engineering. The main scope of the report is to create a thorough understanding of the processes that form, transform and propagate the shoals that cause catastrophic erosion and finding ways to deal with this erosion. The movement of the shoals, but also the entire ebb tidal delta has been analysed for the last 10 years in this report. It is tried to form conclusions from this dataset although some conclusions are still highly uncertain. It is seen that there is not only a episodic erosional trend with a period of around a decade, but also one with a longer period. For both of these types of erosion designs are proposed to mitigate the negative effects of these erosions. It is found that the current practice of 10 yearly nourishments is the most effective way to cope with the erosion. However some notes have to be made that further research can improve the current nourishment strategies.