Tagus estuary (Portuguese Atlantic Coast)

The Tagus estuary, located near Lisbon, is a roughly pear-shaped estuary, approximately 30 km long and varying in width from approximately 15 km at the northern upstream section to 2 km at the downstream entrance, just south of Lisbon, covering an area of approximately 350 km². The circulation inside the estuary is mainly driven by the tidal flow -- the tide has 2 to 4 m amplitude. In the entrance channel the velocity may reach 2 m/s in spring tide. The circulation in the mouth of the estuary is also influenced by the wave field.

The Tagus river is the main fresh water supplier of the estuary with average flow rates of the order of 200 m³/s. Outside the estuary, in the zone where an important submarine outfall is located, the wind and density currents also play an important role in driving the flow, along with the tide. The upstream area of the estuary is very shallow with extensive inter-tidal flats. Downstream, the depth reaches 40 m in the entrance channel. This channel is 12 km long and 2 to 4 km wide.

Prime objectives on this OPCOM site will be to address water quality monitoring in the vicinity of a subsurface effluent outfall.
 

For further information please contact Ramiro Neves (ramiro.neves@hidrox.ist.utl.pt) or Adélio Silva (asilva.hidromod@taguspark.pt).
 

Other OPCOM investigation areas:

• Bay of Marennes-Oléron (French Atlantic Coast)
• Elbe estuary (German North Sea Coast)
• Archipelago Sea and Kyrönjoki estuary (Bothnian Sea)