High resolution topography analysis of Sidi Moussa cliff (Salé, Morocco) to assess coastal flooding susceptibility

Abstract

Moroccan coastal areas are becoming more and more exposed to hazards related to storms and sea level rise. The Sidi Moussa cliff, which is situated south of Salé, is a sensitive coastal sector regularly hit by marine flooding during extreme phenomena. This study will create a high-resolution Digital Terrain Model (DTM) of the area to better determine its morphological characteristics and its susceptibility to marine inundation. The topographic data were gathered by a differential Global Positioning System Real Time Kinematic (GPS-RTK) method. Indeed, the collected data have been treated in a geographic information system environment to generate the DTM and to conduct elevation analyses in detail. The obtained model will be a fundamental dataset for the future numerical simulation of coastal flooding and for the mapping of potentially flooded zones. This study will also offer, for the first time, a clear and detailed morphological expression of the Sidi Moussa cliff, for which no topographic data was previously available. A first look at the results shows a topography that appears irregular, where micro-reliefs and active erosion predominate, increasing the vulnerability of some sectors to wave overtopping during storms. The latter approach points out the contribution of high-resolution topographic data to the enhancement of coastal assessment and management.