Analysis of the Vulnerability of the Senegalese Coast between Djiffère and Dakar by Remote Sensing and Geographic Information System (GIS)

Abstract

The Senegalese coastline is now subject to strong erosion activity, leading to the disappearance of more and more economic infrastructure. The aim of this work is to assess the vulnerability of these coasts on the Djiffère Dakar section with a focus on areas with high economic activity. The methodology consists of using remote sensing methods, Geographic Information System (GIS) and on-site prospecting. The study variables are the rate of erosion of the coastline, the type of relief, the slope, the significant wave height (Hs), the type of land cover and the geology. A GIS model was created to calculate a Coastal Vulnerability Index (CVI) using a weighting method. Based on the CVI values, the rating of these areas is categorized into four vulnerability classes: low, moderate, high, and very high. A vulnerability map of this area is then established. It shows that the odds from Djiffère to Rufisque are more vulnerable compared to that of Dakar with vulnerability indices that vary from 6.13 to 21.4 and from 1.72 to 14.8 respectively. These summary maps of the IVC reveal that the high intensity characterizes above all the highly urbanized sectors, as well as the low-lying reliefs and sandy parts on the coasts from Djiffère to Rufisque. On the other hand, the coasts of Dakar are not very vulnerable due to the rocky outcrops and cliffs which are better protected.