Residual fluxes in a cross-section of the Valdivia River Estuary, Chile

PINO QUIVIRA, M; PERILLO, GERARDO M. E.; SANTAMARINA, P

ESTUARINE COASTAL AND SHELF SCIENCE

Academic Press

Lugar: Londres; Año: 1994 vol. 38 p. 491 - 505

0272-7714

The circulation dynamics, the transport of suspended sediment and salt as wellas the residual flow of water, salt and particulated matter in suspension duringa tidal cycle in the mouth of the Valdivia River Estuary, southern coast of Chile,are analysed. Results show a marked saline and thermic stratification during thelow tide with differences of up to 20%0,and 7 ·C between surface and bottom.Maximum speed of the currents was 0'9 m s - 1 on the ebb direction. Concentrationsof inorganic suspended and combustible matter (organic carbon) werevariable with maxima of up to 7 and 15 mg 1-1, respectively. Residual transportcomputations show that Stokes drift and tidal pumping are important featuresin the net inward transport of water, salt and suspended matter. In the cases ofsalt and organic seston, it cannot be compensated by the Lagrangian transportthrough the section. Also the results confirm the fact that the behaviour of theValdivia Estuary is of the partially mixed type. Previously, this had beendeduced from longitudinal profiles of salinity and temperature.