As a part of the New York (NY) Bight Feasibility Study, a three- dimensional hydrodynamic model of the NY Bight was developed and applied by the Coastal Engineering R h Center of the U.S. Army Engineer Waterways Experiment Station. The study used the three-dimensional hydrodynamic model CH3D-WES for this purpose. A 76 x 45 cell boundary-fitted curvilinear grid was employed in the horizontal and five to ten sigma layers were used in the vertical. Steady- state and diagnostic tests were initially performed, using M, and mixed tides, cross-shelf gradients, winds, and freshwater flows in the Hudson River. All of the tests were successful in reproducing known circulation patterns of the NY bight system. The model was next successfully calibrated and verified against prototype tidal elevations and currents measured during April and May 1976. As a demonstration of the feasibility of long-term modeling, the hydrodynamics, including salinity and temperature, were simulated for the period April-October 1976. Model results compared favorably with available prototype temperature measurements. Model output was furnished to a water quality model of the NY bight, which successfully reproduced the hypoxic event of 1976. Model results also were used successfully to run particle tracking and oil spill models of the NY Bight. Finally, the model was demonstrated for the Long Island Sound and East River areas, for the period of May-July 1990. Computed results for elevation, velocity, salinity, and temperature in the Sound as well as net flux in the East River matched measurements reasonably. Feasibility study, Models, Three- dimensional, Hydrodynamics, Monitoring, Water quality, Long Island Sound, New York Bight.

The New York Bight (NYB) Water Quality Model Study was an investigation of the technical feasibility of applying a numerical three- dimensional (3-D) water quality model to assess the impacts of natural and human activities on the NYB. For this study, the NYB consisted of tidally influenced estuaries, harbors, and bays; Long Island Sound; the Apex region between the open waters of the Bight and the harbors/estuaries; and the Bight, which for this study extended from Cape May, New Jersey, northeasterly approximately 550 km along the coastline to Nantucket Island, Massachusetts, and approximately 160 km offshore to the continental shelf. The depth of the study site varied from 3 m to near 900 m seaward toward the continental shelf. The modeling technology recently developed for the Chesapeake Bay was applied to the Bight. This technology consisted of 3-D, time-varying hydrodynamic and water quality models. The model employed a 76 x 45 curvilinear or boundary-fitted, planform grid and 10 stretched (sigma) coordinate layers for the vertical dimension. The summer hypoxia event of 1976 was selected for the water quality model application, where simulations extended from 15 April through 30 September 1976. The model compared relatively well with observations in the Bight and successfully captured the summer hypoxia of 1976. Simulated net plankton, dissolved organic carbon Dissolved oxygen, Models, Nitrogen, Eutrophication, New York Bight.

This volume to discussing the various aspects of estuarine water quality modeling. Topics considered include fundamental principles, estuarine mass transport, BOD/DO and eutrophication model kinetics, kinetics on toxicants, and sediment-water interactions. The book also discusses mixing zone modeling and how to integrate estuarine hydrodynamic and water quality models. Many case studies demonstrating successful model applications are discussed.