Spatial–temporal analysis of the shoreline change rate using automatic computation and geospatial tools along the Tetouan coast in Morocco

Analyzing and understanding coastline variability and dynamics are important for scientists and policy-makers. This study investigates the long-term process of shoreline change along the Tetouan coast (44 km) for a 60-year period (1958–2018). The shoreline kinematics were analyzed by using high-resolution orthoimages and the Digital Shoreline Analysis System (DSAS). To achieve our objective, the study area was divided into ten beaches grouped into two sectors: (1) the northern sector contained Fnideq, Tres Piedras, Restinga, Smir Marina, Kabila and Golden beaches; (2) the southern sector contained Cabo Negro, Martil, Sidi Abdeslam and Azla beaches. From multi-date shoreline maps, the shoreline change rate was computed using the End Point Rate (EPR), the Linear Regression Rate (LRR) and the Weighted Linear Regression Rate (WLR). Furthermore, the shoreline was classified into eroding and accreting regions through GIS analysis. The accretion and erosion processes along the Tetouan coast were observed to be 94% and 6%, respectively. An analysis of the obtained results showed that the coast was progressive and regressive, at an average rate of 2.81 m/year and − 3.91 m/year, respectively. The overall surface area of the eroded land was approximately 4900,000 m2. In addition, the combined action of the cumulative effects of natural processes and various anthropogenic activities (sand mining, tourism infrastructure, construction of marinas and dams) considerably reduced the sedimentary stock and had negative impacts on the coastal dynamics.