Multi-decadal assessment of shoreline changes using geospatial tools and automatic computation in Kenitra coast, Morocco

Abstract

This study investigates a long-term process of shoreline change along the coastal stretch of the Kenitra coast using geospatial techniques and automatic calculations. A DSAS over a three quarter-centennial period of 78 years (1936–2014) was used. Measurements of shoreline variations were undertaken for three beaches aligned from North to South in Chlihat, Mehdia city, and Sidi Boughaba. The study reveals highly disparate results. Indeed, the maximum recorded coastal erosion/accretion kinematics are +4.7 m/yr, −3.2 m/yr, and −1.97 m/yr respectively for Chlihat, Mehdia and Sidi Boughaba beaches. Noteworthy, are the two 500 m parallel dykes established in 1932 that protect the inlet of the Sebou river stretching from the shore to the ocean. These coastal structures interrupt the long-shore sand movement resulting in accretion on the north drift side and erosion on the south drift side. In addition, the establishment of a dredging platform at the Sebou mouth, has considerably reduced the sedimentary stock, and generated negative impacts on coastal dynamics in the southern part (Mehdia and Sidi Boughaba beaches).