Morphodynamics, sedimentary and anthropogenic influences in the San Vicente de la Barquera estuary (North coast of Spain).

Resumen

The estuary of San Vicente de la Barquera occupies two valleys that have incised into soft sedimentary rocks (Lower Mesozoic) and are controlled by inactive faults. These two estuary subsystems, the Escudo (main valley) and Gandarilla, share outer estuarine zones, i.e., a sandy bay and mouth complex. There is a confining barrier consisting of an aeolian dune/beach system that is currently fixed by a NE-trending jetty that has allowed system progradation over the past 50 years. Connected to the inner inlet in the sand bay is a flood-tidal delta, the most important dynamic and sedimentary unit, which exhibits a heart shape caused by the large amplitude of flows in this estuarine zone and channelizes the flows and sediments into the estuary, primarily during rising and high tides. In particular, a counterclockwise rotation due to the Coriolis effect is essential to the development of this sand structure, including the ebb and flood tide structures, primarily spill-over lobes, sand waves and megaripples.The presence of estuarine beaches into the bay is common in many Cantabrian estuaries, even culminating in small dune fields, in this case with anthropic origin.This paper explains the human occupation and port management, besides the dynamic and sedimentary distribution of a bar-barrier estuary and the changes produced in its distal part by construction of two jetties in the mouth.