This study investigates tidal-wave amplification and phase shift along a propagation path from the northern Arabian Gulf to the Shatt Al-Basrah Regulator (Basrah Province, southern Iraq). We analyze a continuous one-year (2022) record of hourly water-level measurements from two stations located at the entrance of Khor Abdullah and at the Shatt Al-Basrah Regulator. Harmonic analysis was performed using the MATLAB WorldTide toolbox for tidal and tidal-current analysis and prediction. Results show a northward increase in maximum water level, accompanied by progressive amplification of tidal-wave amplitude and an increase in tidal range. At the regulator, the maximum water level is approximately 0.5 m higher than at the Khor Abdullah entrance. Among the resolved constituents, the principal lunar semidiurnal constituent (M2) has the largest amplitude at both stations and increases by ~100% between them. A phase lag of 52.19° (≈108 min) indicates that high tide at the Shatt Al-Basrah Regulator occurs nearly two hours later than at the entrance to Khor Abdullah. These findings provide insight into tidal-wave transformation in the northern Arabian Gulf and may help improve navigation safety, coastal infrastructure planning, and studies of sediment dynamics in the region.

This study investigates tidal-wave amplification and phase shift along a propagation path from the northern Arabian Gulf to the Shatt Al-Basrah Regulator (Basrah Province, southern Iraq). We analyze a continuous one-year (2022) record of hourly water-level measurements from two stations located at the entrance of Khor Abdullah and at the Shatt Al-Basrah Regulator. Harmonic analysis was performed using the MATLAB WorldTide toolbox for tidal and tidal-current analysis and prediction. Results show a northward increase in maximum water level, accompanied by progressive amplification of tidal-wave amplitude and an increase in tidal range. At the regulator, the maximum water level is approximately 0.5 m higher than at the Khor Abdullah entrance. Among the resolved constituents, the principal lunar semidiurnal constituent (M2) has the largest amplitude at both stations and increases by ~100% between them. A phase lag of 52.19° (≈108 min) indicates that high tide at the Shatt Al-Basrah Regulator occurs nearly two hours later than at the entrance to Khor Abdullah. These findings provide insight into tidal-wave transformation in the northern Arabian Gulf and may help improve navigation safety, coastal infrastructure planning, and studies of sediment dynamics in the region.