Shoreline Change and Sea Level Rise Impacts Along Damietta Coast, Egypt: Planning Strategies for Sediment Management and Coastal Planning

ABSTRACT The Damietta coastline along Egypt's northeastern Nile Delta is undergoing persistent shoreline change driven by alongshore sediment‐transport gradients, engineered coastal structures, and rising sea level. This study applies a process‐based numerical modeling chain to quantify decadal shoreline evolution and translate physical findings into policy‐relevant priorities for sediment management and coastal planning in Egypt. Offshore wind and wave conditions from ERA5 are transformed to nearshore wave forcing using Delft3D‐SWAN, and longshore sediment transport and shoreline evolution are simulated using the MIKE 21 LITPACK suite (LITDRIFT and LITLINE). Model calibration is conducted for 2022–2023, and the calibrated parameter set is then applied unchanged to two 10‐year simulations: a baseline case without an added sea level rise (SLR) increment and an SLR‐forced case. Results indicate that incorporating SLR modifies the magnitude and spatial distribution of shoreline excursion, amplifying both erosional and depositional trends relative to the baseline. Gross longshore sediment transport increases under the SLR‐forced case, and peak shoreline retreat exceeds 150 m in erosion‐prone sectors. These outputs support coastal governance in Egypt by identifying priority hotspots and structural transition zones for intervention, informing permitting and sediment‐management decisions, and motivating institutionalized coastal monitoring to enable adaptive shoreline management under SLR.