Monitoring the spatiotemporal variability of beach mesoforms by analyzing Sentinel-2 images

Beaches are extremely dynamic natural environments that experience significant variations at different spatial and temporal scales. The processes of appearance and maintenance of morphological features as the beach mesoforms, as well as their characterization, may provide useful information on the morphodynamic evolution of a beach and the spatial variability of nearshore processes. The high availability of Sentinel-2 satellite images together with the development of tools such as the system SHOREX allows the automatic extraction of the position of the shore. The high accuracy of the resulting satellite-derived shorelines (SDS) offers high potential for the definition of relatively detailed morphological features. This work assesses the ability to apply the SDS for characterizing beach mesoforms appearing at Cala de Mijas, in Málaga (S Spain) as well as characterising their changes over time. The extraction of the SDS enables the characterisation of rhythmic coastal forms through the undulations described by the shoreline position along the beach face by using a sinuosity index and to start to address the study of their relationship with the registered wave conditions. This proves that the information derived from mid-resolution satellite images can become a key source of information to characterize the morphological dynamics of beach environments.