A Topo-Bathymetric Survey of the Morphological Evolution of a Microtidal Barred Beach. Case Study: The Coastal Prism of Korba (Mediterranean Coast; Northeast of Tunisia)
Résumé
For mapping the three-dimensional shape of the submarine bars, studying their dynamics and assessing the spatiotemporal evolution of sedimentary balances, the coastal prism of Korba (emerged and submerged beach) has benefitted from topo-bathymetric monitoring. This monitoring was carried out on an annual basis between July 2006 and July 2009. Numerical Terrain Models (N.T.M.) and transverse profiles were then analyzed. The main results show, firstly, that the shoreface of Korba is characterized by a homogeneous evolution across all profiles of its two-bar system. Moreover, the extent of changes in the sand volume of the beach suggests that the evolution takes place without significant sedimentary loss and that the beach is in a dynamic equilibrium. Accretion of the bars and migration towards the shore are found in periods of small waves (between July 2006 and July 2007). However, following a period of minor agitations, a filling of the outer trough is observed. It is proceeded by the migration of the outer bar towards the coast (between July 2007 and July 2009). These results confirm the traditional model of self-organization of a barred beach. These data and results, then, allow us to establish conceptual models and simulations of the evolution of the microtidal, barred beach of Korba.