The Impacts of Black Sand Mining on the Sustainability of Coastal Dunes Along the Nile Delta Coast, Egypt

The Burullus–Baltim coastal zone of Egypt’s Nile Delta represents a critical geoheritage sand-dune system functioning as the primary natural defense line against inundation of the central Nile Delta. This ecosystem is increasingly threatened by intensive black sand mining, raising concerns regarding long-term coastal sustainability. Black sand extraction disrupts dune integrity by reducing sediment density and heavy mineral content, thereby lowering resistance to wind forcing and accelerating aeolian transport. This study assesses historical dune migration and extraction-driven changes in aeolian dynamics using high-resolution satellite imagery, ERA5 wind reanalysis (1975–2024), and integrated analytical–numerical modeling, with implications for sustainable coastal management. A dominant northwesterly wind regime drives eastward and southward dune migration of 3.22 m/yr and 1.7 m/yr, respectively (2010–2025). Black sand mining since 2022 has measurably reduced heavy mineral content and bulk density, altering grain-size distribution and making dunes significantly more susceptible to wind entrainment. Coupled Bagnold and AeoLiS modeling predicts an 8.21% rise in mass transport rates and a corresponding acceleration in dune migration following extraction. These findings demonstrate that black sand mining amplifies aeolian transport and increases sand encroachment risks to nearby settlements, infrastructure, and agricultural lands. The results highlight the trade-offs between resource extraction and coastal dune ecosystem services, particularly flood protection and land stability, emphasizing the need for regulated mining, bioengineered dune stabilization, and predictive modeling to enhance the Nile Delta’s long-term resilience.