TRANSVERSE VELOCITY AND SALINITY VARIATIONS IN THE TEES ESTUARY

Transverse variations in velocity and salinity were observed at four sections across the Tees Estuary. At each section, measurements were made simultaneously at two or three cross-stream positions over a full tidal period. The selected sections lay within two straight portions of the estuary, at a sharp bend and close to the end of a tide-training wall. Analysis of the velocity data suggested that lateral changes in the vertical gravitational circulation contributed to the net transverse circulation. The depth mean salt fluxes per unit width associated with transverse deviations from the cross-sectional means of the steady and tidal flows showed appreciable variation across the estuary, particularly where there were marked changes in the topography. Cross-stream changes in the salt flux arising from the vertical gravitational circulation were similar at each of the sections considered despite the appreciable topographic variations. Since all three fluxes are included in the longitudinal dispersion coefficient in a laterally averaged estuary model, such a coefficient will be dependent on both the topography and the freshwater flow. © 1979.