Coastal morphology of the Bahía Blanca Estuary, Argentina.

MELO, WALTER D; SCHILLIZZI, ROBERTO A; PERILLO, GERARDO M. E.; PICCOLO, M CINTIA

Mar del Plata

Congreso; Joint IAPSO-IABO Assemblies, 2001: An Ocean Odyssey; 2001

IAPSO-IABO

The Bahía Blanca Estuary, located in the Southwest of the Buenos Aires Province, Argentina, covers asurface of 2500 km2. Its reception basin of has a total surface of 19000 km2 which extends from theSierra de la Ventana range to the northern border of the Colorado River. The objective of this work is tocharacterize the coastal morphology of the of Bahía Blanca Estuary in relation with its reception basin.Several small rivers and creeks reach the estuary along the northern coast of the Canal Principal that havegenerated extensive alluvial deposits in the coastal sector, originating wide tidal flats and salt marshes.On the northeast, the marine dynamics acting since the last higher stand of the sea level, conformeddiverse morphologic units composed by spits, cliffs and sandy beaches backed by coastal dunes. At thehead of the Canal Principal a salt flat has developed in connection with the former fluvial channels thatoriginated the old delta. At the present time it became a lagoon and, in turn, as an area of reception for alimited river basin without direct connection with the estuary. On the southern sector of the estuary thebasin is conformed by an alluvial plain originated by the contributions of the Colorado River which nolonger discharge into the estuary. The coastal line is interrupted abruptly due to the presence of extensiveerosion areas surrounded by wide tidal flats.