SALINITY AND WATER CIRCULATION IN THE VELLAR ESTUARY

Abstract

This paper reports a series of measurements of salinity, temperature, and current velocity in the Vellar estuary. This typical bar‐built estuary is shown, by comparison with dimensionless stratification parameters, to be a salt wedge at high river discharge and well stratified at low river discharge. During the tidal cycle, the salt wedge near the bottom became isolated in a series of basins during ebb tide; short period diffusion along the intense halocline seems to have been an important process in the salt balance of the water column. The water circulation at high river discharge was dominated by a meander system of alternating scour holes, with the high seaward flow in the deepest areas. Superimposed on this was a secondary lateral circulation system that broke down and reversed its sense at low river flows when the saline inflow developed.