Multi-decadal evolution of the Moroccan Atlantic shoreline: A case study from the Essaouira coastal sector

The degradation of coastlines is a result of global warming, which is closely accompanied by rising sea and ocean levels, as well as anthropogenic activities. The systematic fixation of mobile dunes has proven to be a positive environmental practice thus far. To accurately assess and predict future trends, it is essential to analyse the position of the coastline and understand its dynamics over time. In line with this goal, a study was conducted to investigate the decadal evolution of the sand shoreline along a 25 km stretch of the high-energy low-coast of Essaouira (Morocco, NW Africa). Landsat satellite images were used spanning a period of 30 years (1990, 2000, 2010, and 2020) and employed the digital shoreline analysis system model (DSAS) in conjunction with morpho-sedimentary dynamics analysis. Additionally, Google Earth satellite images from 2007 to 2022 were consulted to gain insights into the cyclical morpho-sedimentary processes that affect the beach/dune system. The findings revealed that the Essaouira coast has experienced landward migration of the coastline, leading to the retreat of beach/dune systems. Transgressive dunes, which had been fixed previously, were reactivated as part of this process, contributing to the morpho-sedimentary impacts observed along the coast. •The landward migration of the shoreline along the coast of Essaouira is evidenced using satellite images from 1990 to 2020.•In the north coast, it decreases from 41.83m to 25.90m in a N–S direction. In the southern end, maximum and minimum retreats are 63.10m and 14.28m.•The Diabet beach experienced seaward progradation by 22.18m, but the north and broad southern segments are irregularly retreating.•Since 2010, transgressive dunes more developed southward are cyclically restored. Advance rates (m/month) have been recorded.