Etude descriptive de l'evolution saisonniere des dunes bordieres de la plage de Korba (facade orientale,Cap Bon) par la methode de des Modeles Numeriques de Terrain Residuel.

Abstract

The study of the dynamic of bordering dunes of the beach of Korba consist of analyse and quantify their seasonal evolution according to numerical and topographic approach. This is defined by representation of the morphologyof bordering dunes and the qualification of their evolution by using the Digital Terrain modeling (DTM). The principal results obtained show that the morphological evolution of dunes can be synthesized according to two profiles, in reaction to hydrodynamic variability. The winter profil, when the conditions of agitations increase in autumn, bordering dune and beach are destructed and summer profil when the conditions of agitation are week, we marqued an accretion of both of dune and beach. We have generated from the topographic sunrises, on two different periods, the Residual Digital terrain Model. The latter allowed quantifying topographic variation of bordering dunes controlled by climatic and ecological factors. This approach allowed the estimation of the scale of seasonal dune mobility. It is of the order of few millimeters between two different summer periods and some centimeters in one meter between winter and summer periods. The aim of this study is to provide reliable information of dynamics and seasonal kinematics of bordering dunes in order to integrate specificities of this geomorphologic unit in the politics of planning to protect the coast.