Nearshore evolution at Noordwijk (NL) in response to nourishments, as inferred from Argus video imagery

Abstract

We use an approximately 16-year long data set of daily low-tide video images to examine the effect of three consecutive nourishments on the temporal evolution of the subtidal sandbars and the low-tide water line at Noordwijk, The Netherlands. The data set starts in 1995, with shoreface nourishments implemented in 1998 and in 2006, and a "Zwakke Schakel" beach nourishment in 2007/2008. We find that, consistent with observations elsewhere, the shoreface nourishments halted the interannual, net-seaward migration of the two sandbars. Also, the first nourishment resulted in large-scale sandbar variability known as bar switching. The beach nourishment had no effect on the sandbars, other than an immediate 50-m seaward shift of the low-tide waterline and the inner sandbar. Neither the shoreface nor the beach nourishments were found to result in an increase or decrease in the number and cross-shore extent of rip channels. On the whole, the successive nourishments have reduced the natural dynamics of the Noordwijk coastal system.