Hydraulics and Thermal Dispersion in an Irregular Estuary

The model is based on the open-channel hydraulics equations in two dimensions. A unique feature is the use of a coordinate transformation to map the irregular shoreline into a rectangular computational space, thereby simplifying treatment of boundary conditions. The hydraulic flow field is calculated separately from the temperature field, due to the large difference in stable step size for the two calculations. The results of the hydraulics calculation, which become periodic after about one and one-half tidal cycles, are stored on magnetic tape for use in the temperature calculation. The temperature field arising from a power plant thermal discharge requires 15 or more tidal cycles to become periodic, due to the gradual diffusion of heat away from the outfall by oscillating tidal currents. Sample temperature calculations are presented which illustrate the effect of the oscillatory tidal flow on the temperature distribution near the outfall.