Sea Level Analysis for Tidal Datum Realization at Port Tawfik, Suez, Egypt

Abstract

Nautical charts play a crucial role in ensuring safe and efficient navigation on the world's waterways. The accuracy of these charts, particularly in terms of nautical chart datums, is of the utmost importance to protect maritime vessels and enable precise navigation. Furthermore, the continuous process of updating and validating nautical chart data is of considerable importance to authorities and decision-makers since it enables them to make informed and accurate judgments in maritime operations. Due to sea level fluctuations caused by climate change and land subsidence, regular updates are essential. The objective of this research was to determine the tide levels at the southern entrance to the Suez Canal at Port Tawfik using hourly sea level data collected in the port area over four years (from June 2010 to July 2014). Harmonic analysis was implemented to separate tidal and non-tidal components of sea level using Geo-tide software. The algorithm showed that the dominant tidal constituents were M2, S2, K1, and O1 with amplitudes equal to 0.551, 0.143, 0.036, and 0.011m, respectively. The phase angles of these constituents are 330.57, 0.45, 183.05, and 199.35°, respectively. These components are fundamental in tidal datum calculations. Furthermore, results showed the calculated values of highest high-water level, lowest low-water level, mean high water springs, mean low water springs, mean high water neaps, mean low water neaps, highest astronomical tide, and finally lowest astronomical tide to be as follows: 19.11, 17.63, 19.06, 17.67, 18.78, 17.96, 19.37, and 17.37m, respectively. Furthermore, a safety margin of (± 0.10m) was added to all estimated values, as the Naval Recruiting and Training Agency recommended. Finally, the values of tidal datums calculated were compared with the predefined values in the Admiralty tidal publication, revealing a difference of (+ 0.20m) between the two years of 1906 and 2014.