Tide gauge at the commercial port of Faro

1 Jul 2022 | Announcements

Tide gauge at the commercial port of Faro

If it is true that the altitude of a given place is measured through the mean sea level, then another question arises here: how will the mean sea level itself be measured? This is where the tide station comes in.

This instrument records the tidal amplitudes at a certain point in the coastal zone, and as a rule this type of instrument is installed in sheltered areas, inside a small building or any structure fixed in ports or piers.

The tide gauge is therefore a discreet instrument, and the truth is that there are already a few distributed throughout Portugal, with a tide gauge having recently been placed by the LS Engenharia Geográfica team at Faro's Commercial Quay. This was the result of a protocol established between the Sines and Algarve Harbour Authority and the LS Engenharia Geográfica, thus ensuring its installation and respective maintenance, thus entering into operation in January 2022, having only become available for consultation on our website in June of this year.

How do tide gauges work?

These instruments traditionally took the form of a buoy and were connected to a recording system made with a roll of paper that slowly rotates around a drum, set by the rhythm of a clock. It is on this paper, with the aid of a pen, that the level of the buoy is marked, allowing the tide gauge to record the faster and slower oscillations of the water level, due to astronomical effects, the effect of the waves, the intervention of the wind. the swell and the currents. The Cascais tide station (altimetric reference of mainland Portugal) is an instrument of this type, being the oldest in the world, still working perfectly since 1882. The most modern tide gauges are made up of sensors, hardware and software, which allows for great flexibility usage, as well as real-time access to readings via a web connection.

The Cascais tide gauge (reference altimetric of Mainland Portugal) is an instrument of this type, being the oldest in the world, still functioning perfectly since 1882. The most modern tide gauges are made up of sensors, hardware and software, which allows great flexibility of use, as well as access in real-time readings, via a web connection.

Once all these data have been recorded - over an extended period - it is necessary to carry out several calculations in order to accurately identify the mean sea level.

And so, the mean sea level may be called zero level, or chart datum, a geodetic reference from which altitudes are measured, information that is extremely necessary both for the definition of topographic and hydrographic shapes, but also for navigation safety.

Why was one installed at Cais Comercial de Faro?

When we talk about Faro, we inevitably talk about a coastal city, where a large part of the population dedicates their time to the sea and to activities such as sailing and fishing, both from a recreational point of view and as a way of supporting themselves.

Faro is also - through the University of the Algarve - a very important center for marine scientific research, and this region is still served by the Port of Faro, a structure capable of receiving cargo ships with a draft of more than 6 meters, and hence the importance of stablish a tide station inside the Ria Formosa that would allow accurate and recurrent recording in this area characterized by the strong influence of the tides on the hydrodynamics of the channels and bars.

What are the purposes of using this tide station?

This type of instrument, as a rule, is used by scientists and researchers to obtain real and exact readings regarding the tides and their characteristics, data that end up serving as a scientific basis for carrying out various studies on the sea.

Furthermore, the population living in the coastal regions of Portugal is already familiar with the issue of rising and falling tides, and with the influence that variables such as wind and atmospheric pressure can have on this type of phenomenon.

According to the Intergovernmental Panel on Climate Change (IPCC), and based on information collected by tide gauges, sea level has been rising globally in the last century, between 10cm and 25cm, approximately, and it is expected that in the next century, this average increase reaches 50cm, thus reinforcing the need to prepare contingency plans as a response to impacts on the coastal zones.

How can this service be accessed?

Thinking of all those who need to resort to detailed information on the characteristics of the tides, to support navigation or carry out maritime work, LS Engenharia Geográfica provides from now on a service that gathers all the information collected by the commercial wharf tide gauge. from Faro.

Through this service, you will be able to access data on the height of the tide, local atmospheric pressure and water temperature, all this at the distance of a link, visiting our website. The scientific nature of this initiative will allow for the registration of these variables and for share it with the local community and other institutions.

If you are currently carrying out a detailed study and need access to a specific set of data, just contact us to obtain the necessary permissions to use this data, in a simple and immediate way.