A diachronic study of the Mediterranean coastline: A geometric approach

Abstract

Coastal areas represent one of the country's most important environmental and economic resources. They are naturally dynamic, with changes that can occur on a human time scale and that need to be quantified for the proper management of shorelines and, in particular, the beaches on which the local economy is largely based. This work focuses on the diachronic study of the coastline of the Mediterranean coast, particularly the coastal fringe at the mouth of the Wadi Aliane. In order to assess and remedy the risks of erosion and accretion of the coastline, the methodology followed consists of the application of automatic analytical techniques using multi-temporal photo-interpretation, a Geographic Information System (GIS) and a Digital Shoreline Analysis System (DSAS). The rate of change will be calculated from the multi-date maps, (1981- 1997 and 2016) using the End Point Rate (EPR) index. Comparison of the results of the interpretation of aerial photos and satellite images of the Oued Aliane coastline used (1981, 1997, and 2016) provided information that allowed us to understand the evolutionary behaviour of the wet sand/dry sand line over 36 years. This numerical analysis of the 1981 -1997 and 2016 coastlines in the coastal sector of Oued Aliane, shows us that zones A, C and D are mainly affected by erosion, while the mouth part is affected by accretion because it is considered a delta and therefore a sedimentation area.