A continuous revise and validation for all information on nautical charts is very vital
for responsible authorities to take the right decision, especially the guidelines about
tidal datum connection with the geodetic vertical datum. This data is needed to be
updated continuously as a result of sea-level changes beside tectonic plates movements.
The current paper's primary objective is to calculate the tidal levels in Port Said (PS)
on Eastern Mediterranean Sea. Hourly sea-level dataset was collected inside Port Foad
port, which enclosed with Port Said harbor in the same basin. Harmonic analysis was
applied using TIDE tool of Delft-3D hydrodynamic mode. Tidal regime ratio was
calculated using Form Factor (FF)equation, indicating 0.21 that expresses semidiurnal
tidal domain in the area. Tidal datum levels were realized referred to the Egyptian
Surveying Authority (ESA) zero datum, as provided by the Suez Canal Research
Institute (SCRI). Furthermore, tidal levels were calculated using MATLAB, fulfilling
the most recent definition for both lowest (LAT) and highest (HAT) Astronomical
Tides accredited by the International Hydrographic Organization (IHO). Based on the
results of analysis and calculations, ranges between highest and lowest same
expressions (MHWS & MLWS, MHWN & MLWN, HHWL & LLWL, HAT & LAT)
were equivalent to (0.368, 0.096, 0.4372, 0.496 m) respectively. According to the
Naval Recruiting and Training Agency (NRTA) a safety margin of (± 10 cm) was added
to all calculated levels. Moreover, from statistical analysis of observed sea level dataset,
it was found that the highest observed water level is (19.128 m), while the lowest
recorded water level is (17.318 m), which means a range of (1.81 m) with standard
deviation (0.16 m), referred to the (ESA) Zero level. In a nutshell, there is a constant
deference in LAT between 1906 - 2015 by 20 cm due to the new definition of LAT
level by IHO in 2011, that increased the values. Additionally, HAT and LAT
astronomical level values are recommended to be updated in all concerned nautical
publications by 18.72 m and 18.01 m respectively, that means astronomical tidal level
range equals (0.516 m) referred to the same datum (ESA) zero level. |
