ABSTRACT
Tidally averaged models predict variations in transport and concentrations over relatively large space scales and on time scales of weeks, or longer, since tempored averaging tends to suppress small-scale activity. The modified tidal prism method estimates tidal dilution from the total amount of water entering the estuary from tidal inflow. D. W. Pritchard developed a method for estimating the steady-state flows and pollutant concentrations from salinity distributions for a two-dimensional estuary. Wu-Seng Lung and D. J. O'Connor described a method for estimating vertical and longitudinal velocities in an estuary using salinity profiles. The approach described for computing the residual flows can easily be extended to multidimensional models. In many hydrodynamic model applications, the spatial resolution is relatively fine, on the order of hundreds of meters to a few kilometers. The spectral analysis, leading to the density distribution, provides an indication of the time scales over which processes occur.
