IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Circulation pattern in a tidal channel influenced by tributary channels and adjacent tidal flats
Autor/es:
PERILLO, G.M.E.; LOPEZ GREGORI, M.; ALVAREZ, L.I.
Lugar:
Rio de Janeiro
Reunión:
Simposio; IEEE/OES ACOUSTICS IN UNDERWATER GEOSCIENCES SYMPOSIUM; 2017
Institución organizadora:
IEEE/OES ACOUSTICS IN UNDERWATER GEOSCIENCES SYMPOSIUM
Resumen:
Abstract?The main objective of the present paper was todetermine the general circulation pattern and also evaluate howthe tributary channels and the extensive tidal flats along bothbanks on the Canal Principal influence the pattern. Currentvelocity and direction data were obtained near the head of CanalPrincipal of the Bahía Blanca Estuary during a spring tidal cyclewith a total of seven transects transversal to the channel.Geomorphologic and hydrodynamic characteristics of the studyreach were made with an Acoustic Doppler Current Profiler(ADCP) mounted on a ship and positioned with a DGPS-RTK.The tide and wind data were obtained by means an Estación deMonitoreo Ambiental Costero (EMAC) located at PuertoCuatreos, at the center of the study reach. The ebb currents arestronger although the flood stage is longer; however, it cannotbalance the former resulting in an ebb-dominated circulation.Inside the study region, the circulation is affected by the channelcurvature. The ebb current has a predominant role in modelingthe meander. Most of the transects located between PuertoCuatreros and the Maldonado Channel show a nucleus of highervelocities in the center, decreasing in the vicinity of the channelbed and the flanks.. Near low-tide slack water somedissimilarities were observed developing a two-layerstratification of the flow, which although it has been reportedbefore in the estuary, never measured in detail. During ebb, fromthe analysis of the data in the area of channel confluences, ashear layer was observed due to the interaction between the mainstream and the discharge from the tributary channels..Meanwhile, during the flood, decrease in the speed and adeviation of the main flow direction, were detected as aconsequence of the flow separation due to the presence of thetributary and the tidal flats (specially in the later part of theflood). In the area of Puerto Cuatreros wharf, a currentacceleration towards the center of the channel was detected,producing a vertical flow adjacent to the wharf. Finally, using thebackscatter intensity data provided by the ADCP, a qualitativeanalysis of the sedimentary dynamic over the study region wasmade.