Coastline undulations on the West Coast of Denmark: Offshore extent, relation to breaker bars and transported sediment volume

Abstract

This paper deals with field measurements of undulations of the bottom bathymetry along an otherwise straight coast at the Danish West Coast. Two bathymetric datasets and two time series of wave measurements are used in order to determine the following properties: the offshore extent of shoreline undulations, the amount of sediment transported alongshore in the shoreline undulations, the relationship between the shoreline undulations and longshore bars and the relationship between the morphology and the hydrodynamics. In one of the data sets the shoreline undulations are well correlated with undulations on the depth contours between −5m and +2m relative to mean sea level. In the other data set, only undulations on the depth contours between −1m and +1m are well correlated with the shoreline undulations. The main difference in the wave climate between the two locations is the orientation of the shoreline such that the wave incidence angle is more oblique on the section of shoreline with well correlated depth contours, suggesting that the well correlated depth contours are a result of the oblique wave incidence.