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Hydrographic Surveys in the Algarve - FLOODS Project
Under the contract signed between the public company Águas do Algarve SA and the LS Engenharia Geográficahydrographic surveys were carried out during the months of March and April 2023 on the Odelouca and Arade streams, including the estuary and port areas.
These works fall within the scope of the FLOODS project – New tools for the prevention, alert, coordination and management of Emergency Floods at local level, co-financed by the European Program – Atlantic Area; an application that aims to produce and test new tools, plans and regulations that improve the management and response to flood situations in the hydrographic region of the Algarve.
Hydrographic Survey Specifications
The terms of reference for this work provided for the acquisition of bathymetric data in the Odelouca and Arade streams, using acoustic systems and GNSS positioning, therefore, hydrographic surveys of Order 1a, according to the specifications of the International Hydrographic Organization.
Challenges and Characteristics of the Region
The Odelouca and Silves zones are characterized by very shallow areas that are not very accessible to navigation. The operations involved the use of vessels with very low draft and outboard engines, and working hours were always dependent on high tide periods, so as to be able to characterize areas of the bottom that remain emerged for most of the time of the day. In a river path with an approximate length of 10 nautical miles and an average depth of about 2 meters, depths ranging from -2 to 10 meters (referred to the Chart Datum), the greatests, were observed near the city of Portimão , where the river Arade, when approaching its outfall, exhibits a greater flow, resulting from currents and tides.
Hydrographic Coverage and Natural Beauty
As a matter of curiosity, the hydrographic coverage of this basin was carried out using a single-beam system, defining a minimum spacing of 15 meters between rows. In a total work path of 80 nautical miles, areas of great beauty could be observed, with no human footprint on their banks, and where some species of mammals and birds less known in the region, still inhabit.