Topo-hydrographic survey in the islands of Madeira and Porto Santo

A team of four soldiers from the Hydrographic Brigade (BH) carried out topo-hydrographic surveys (LTH) on the islands of Porto Santo and Madeira, from March 18 to April 9, 2022, in order to obtain updated topo-hydrographic information. for the purpose of cartographic updating.The BH team embarked on the 18th of March aboard the NRP D. Carlos I, together with the sounding vessel Mergulhão, equipped with a high resolution multibeam system. Equipment for topography, geometric leveling and three field tide gauges were also mobilized.On March 21, the team with Mergulhão landed in the port of Porto Santo to carry out the first survey. This LTH lasted one and a half days, during which soundings were carried out in the port of Porto Santo, installation of a tide gauge, Geometric Leveling (NG), GNSS coordination of 6 Support Points (PA) and topography with cartographic interest.On the 22nd of May, the team and Mergulhão returned to board the NRP D. Carlos I towards the island of Madeira, where they disembarked the following day, together with the hydrographic boat and all the material.During the two-week stay on the island of Madeira, 3 hydrographic surveys were carried out: the port of Funchal, the port of Caniçal and the Garajau nature reserve. 9 support points were also coordinated, geometric leveling was carried out in three locations and field tide gauges were installed – one in the port of Funchal and the other in the port of Caniçal.In total, 3 field tide gauges were monitored throughout the mission period. The Funchal tide gauge, which belongs to the national tide gauge network of the Hydrographic Institute, was maintained.In this mission, the recovery of PA with NG was carried out in Porto Santo, Caniçal and Funchal, reestablishing a robust local network of PA with NG, with the concern of these prevailing over time.The establishment of a robust network of support points was essential for the study of a model of the global geoid EGM 2008 1' to verify its applicability to the various ports. This study was conclusive, and the model was applied to the hydrographic data with the introduction of a vertical adjustment, different for each port, in order to reduce the ellipsoidal altitude to the orthometric altitude obtained by geometric levelling.

In this mission, the updating of hydrographic information in the ports stands out. This information is extremely important for the safety and maintenance of the confidence of maritime operators, knowing that the port of Funchal is one of the main ports in Portugal, currently being the national port with the highest number of tourists and the 13th in terms of and the port of Caniçal, a sensitive place for supplying the island of Madeira, where container ships, ships carrying fuel and fishing vessels dock.A hydrographic survey was also carried out in the Garajau partial natural reserve, thus contributing to the sustainable development of Madeira in the protection of the marine environment and knowledge of its natural riches, enhancing the increase of knowledge of the seabed with bathymetric models of high resolution that allow a planning and mapping in the control of the species that inhabit the place.