Measuring the effect of wind-driven processes on coastal dunes: a study of the Atlantis and Geelbek dune fields along the West Coast of South Africa

Abstract

Dunes are dynamic features that can change location, shape or extent depending on wind direction and strength, the vegetation cover, temperature and moisture. This study focus on the primary factors impacting the change dynamics of sand dunes which are wind direction and wind strength. Two methods exist for measuring and detecting sand dune movements, namely, in situ surveys and change detection through remote sensing. This study applied change detection through remote sensing by using satellite imagery as methodology to monitor the movement and extent of change of two prominent coastal sand dunes located along the West Coast of South Africa. The significance of this study is to highlight the changes that occurred in the Atlantis and Geelbek coastal dune fields over the period 1998 to 2018 ascribable to the effect of wind-driven processes. The results showed that both these two dunes experienced more or less the same extent of movement and the direction of movement correlated well with the direction of the stronger summer wind-driven processes on the West Coast. However, it was also recorded that the extent of change of the dune fields were irregular.