Volume changes on a coarse-grained beach in relationship with wave data

Abstract

San Felipe is a mixed beach located in the northern coast of Gran Canaria Island. This study of volume changes over time has been carried out using elevation models which have been obtained from topographic data. Eighteen surveys were performed where data were taken from the entire beach with a total station. Wave data is the main factor involved in the volumetric changes of the beach. The most relevant parameter is the maximum significant wave height, which relates very well to the volume changes in the beach throughout the study period (R2=0.73). On the other hand, wave direction determines if the beach accumulates or erodes. Storm events are often from the NW and are associated with high wave heights, which are responsible for the largest accumulations of cobbles and pebbles that have ocurred throughout the study period. Conversely, in periods of calm prevail NE wave that cause erosions of up to 450m3 between two consecutive surveys. However, this last factor also depends on the maximum significant wave height since the results shows that with small changes both positive and negative values have the same direction wave.