Application of a Three-Dimensional Water Quality Model to the James Estuary

Abstract : Water quality models continue to increase in options and accuracy as super computer access becomes a reality for water quality management. The US army Corps of Engineers (USACE) Waterways Experiment Station (WES), in Vicksburg, Mississippi has developed a state of the art modeling framework for simulating the hydrodynamics and water quality standards of the Chesapeake Bay. As environmental engineers focus more attention on Bays tributaries this year, this complicated model must be accurately applied to the major freshwater rivers emptying into the Bay. To discover the feasibility of applying the models to a smaller estuary system, the Chesapeake Bay model was reconfigured and applied to the James River Estuary in Virginia. The alteration mandated input file data reconstruction and development, basin mapping, and site specific code adjustments for the models and the postprocessor. The model size and memory needs dictate super computer enrollment for accurate and timely system utilization. The model was calibrated using salinity data on the James Estuary, and verified by dissolved oxygen and chlorophyll a responses to nutrient loadings. A model sensitivity analysis of the results was conducted to ensure that reliable results were obtained.