AN ANALYTIC MODEL OF TIDAL CIRCULATION IN A NARROW ESTUARY

A simple model of open coastal dynamics is adapted to provide an analy tic solution of the vertical and axial structure of tidal currents in an estuary. Applied to the Hey River estuary in northern Queensland, t he model provides an accurate representation of the four major tidal c onstituents. By best-fit analysis of the model results to data from th ree current meters, the vertical eddy viscosity for the estuary is est imated as 2.8 x 10(-3) m2 s-1, and the linear friction coefficient as 8 x 10(-4) ms-1. Bottom boundary considerations indicate that the data are consistent with the concept of a bottom logarithmic layer 0.6 m d eep, in which the eddy viscosity increases linearly from near-zero to its free-stream value.