Hydrodynamics and sediment dynamics of an estuary with an abrupt depth step

PEREYRA, MARIANA G.; MARINO, BEATRIZ M; SZUPIANY, RICARDO N.; THOMAS, LUIS P

JOURNAL OF HYDRAULIC RESEARCH

INT ASSOC HYDRAULIC RESEARCH

Lugar: Madrid; Año: 2014 vol. 52 p. 532 - 544

0022-1686

The hydrodynamics resulting from the combination of tide, riverine discharge and bathymetry on the water circulation and sediments transport is characterized to address the impact of geomorphologic changes in the Quequén Grande River estuary (Buenos Aires, Argentina). A depth step located at about 2 km from the sea, created by dredging to provide adequate navigability conditions in the harbour, induces different flow patterns in the deeper and shallow estuarine parts, creating an attractive system to study. The main purpose of this article is to introduce the present physical features of the watercourse and the results of detailed longitudinal and transverse measurements of velocity and backscattering intensity that evidence the selective settling of suspended solids in the harbour and a net loss of sediments to the sea. The effects of local severe storms that cause an intense tidal intrusion and mixing, as well as a stronger ebb flow and seiches, are also described.