Abstract:

The objective of this article is the spatiotemporal monitoring of coastline and beaches in relation to hydrodynamics and sediment dynamics. Since the study area is local, it is important to carry out a very high spatial resolution study. To achieve our goal we used satellite images with a spatial resolution of 0.2 m on the one hand and the high-resolution SWAN model on the other hand. We have transformed satellite images into coastlines. For the diachronic study we used ArcGIS to create a mosaic of images, to rectify these mosaics and to calculate the distances separating the coastlines taken on different dates. We observed the presence of erosion/accretion on several beaches. This evolution can be explained by the effect of the maritime structures and the contributions of the wadis. Wave energies are distributed unevenly along the coast due to the bathymetry of the area and the orientation of the coastline. The study of the sedimentary dynamics based on the granulometric study of the surface sediments and the extrapolation of the different granulometric indices under ArcGIS allowed us to show the distribution of different sedimentary facies on the surfaces of the studied beaches. We noticed a concordance between the distribution of wave energies and the evolution of the coastline. On the other hand, the combination of the results obtained and the granulometric analysis allowed us to explain the distribution of sedimentary classes.

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