Diachronic and historical evolution of the Al-Hoceima Bay coastline, Moroccan Mediterranean Sea

Abstract

Al-Hoceima Bay, located on the northern coast of Morocco, holds significant environmental importance. It also faces environmental challenges, including the pressures resulting from urban sprawl and growing number of tourists, as well as the impacts of climate change. The objective of this study is to assess the coastal changes in Al- Hoceima Bay since 1964, considering both natural and human factors. This study is based on the diachronic analysis of aerial photographs taken over a period of 56 years, utilising the digital shoreline analysis system statistical technique to calculate the shoreline’s mobility index for each period. The results demonstrate significant erosion at the Tayth beach (−1.50 m∙y−1) and Souani beach (approximately −1.90 m∙y−1), whereas accretion was experienced at the Sfiha beach at a rate of about +1.11 m∙y−1 and at the Lharch beach at a rate of +0.92 m∙y−1. The mouth of the Nekôr River experienced the highest retreat at −3.15 m∙y−1, followed by Ghiss at −2.00 m∙y−1. These findings indicate the impact of human interventions, such as the construction of the Mohamed Ben Abdelkarim El Khattabi dam on Oued Nekôr since 1981, as well as climate changes that have led to decreased flow, particularly at Oued Ghiss. These combined climatic and anthropogenic impacts have exacerbated erosion and disrupted the sediment balance along the shoreline of Al-Hoceima Bay.