Shoreline change and hydroclimatic variability at Ras Al-Katib, Red Sea coast, Yemen: implications for coastal conservation and management

Ras Al-Katib is a dynamic coastal barrier adjacent to the Port of Hodeidah on the Red Sea coast of Yemen, where shoreline instability may affect coastal infrastructure and navigation. This study quantifies shoreline change along a 5.6-km sector and evaluates its consistency with regional wind and offshore wave forcing. Multi-temporal satellite imagery from 2000, 2010, and 2020 was analysed using the Digital Shoreline Analysis System (DSAS), while hourly wind data (2000--2020) and ERA5 wave parameters (2001--2020) were assessed, with ERA5 evaluated against buoy observations from 2003--2004. DSAS revealed predominantly erosional behaviour in the central sector, with maximum shoreline retreat of approximately 109~m (5.5~m~yr⁻¹), whereas the northern sector experienced accretion of approximately 93~m (4.66~m~yr⁻¹). ERA5 showed good agreement with buoy-observed significant wave height ($r = 0.831$; RMSE = 0.199~m; bias = +0.005~m) and captured the broad directional regime, with 80.3% of estimates within ±45^∘ of observations. Extreme-wave directions were strongly concentrated from the south (175.4^∘ ± 6.5^∘), consistent with the previously documented winter hydrodynamic setting. No significant trend was detected in offshore significant wave height during 2001--2020 ($p = 0.898$), nor in mean air temperature during 2000--2020 ($p = 0.450$). The spatially contrasting shoreline response is consistent with seasonal wind forcing and previously documented nearshore wave transformation that favours alongshore sediment redistribution. These findings provide a quantitative basis for coastal monitoring and adaptation planning and highlight the need to account for episodic wave forcing when assessing shoreline stability along the Red Sea coast of Yemen.