Influence of tidal inlets on salinity and related phenomena in estuaries.

This study presents mathematical hydrodynamic and salinity transport models applicable to the analysis of the effects of tidal inlets on bays and estuaries having the typical morphology encountered in the U.S. coastal regions on the Gulf of Mexico. The practical utility of these models has been developed and demonstrated for the following specific cases: (1) Simulation of tidal hydrodynamics and salinity distributions under well-mixed water conditions for two bays on the Texas Gulf Coast; (2) Analysis of the effects of altering natural tidal inlets on estuary-Gulf exchange and on salinity concentration, transport and distribution. Analyses were conducted on both idealized and real estuaries; (3) Simulation and analysis of hypothetical shell reef removal. Specifically, Matagorda Bay, Texas, was used to verify both the tidal hydrodynamic model and salinity distribution model. Galveston Bay, Texas, was used to demonstrate the effects of altering the size of the tidal inlet on water interchange and salinity distribution. Using computed 'baseline' conditions for low and intermediate freshwater inflows to Galveston Bay, the assumption was made that an improved, continuously open tidal inlet was created at Rollover Pass into the Galveston Bay system. Changes in salinities, salinity gradients, Gulf inflows, tidal prisms, and circulation were computed for intermediate and low fresh water inflows.