WQMAP: An integrated three-dimensional hydrodynamic and water quality model system for estuarine and coastal applications

WQMAP is an integrated system for modeling the circulation and water quality of estuarine and coastal waters. Tfie system includes a suite of integrated environmental models including a boundary conforming grid generation model, a three hydrodynamic model, and a suite of pollutant transport and fate models (single and multiple constituent and WASPS eutrophication kinetics). All operate on a boundary conforming grid system and are supported by an embedded geographic information system and environmental data management tools. WQMAP is configured for operation on a Pentium personal computer and features a Windows based user interface. The interface employs point and click and pull down menu operation. Color graphics and animations are used to display model predictions. The system is structured to facilitate application to any geographic area. As an illustration of its capability WQMAP was applied to predict the three-dimensional circulation and thermal dynamics for Mt. Hope Bay, RI, located on the eastern side of Narragatisett Bay. Tlie area receives fresh waler input from the Taunton River and a thermal discharge from a 1600 MW coal and oil fired power plant located at Brayton Point, along the north shore of the bay. Model predictions were performed for the month of August 1997 and compared to time series at three stations in the vicinity of the power plant discharge. Measurements of currents, temperature, and salinity were made near the surface and the bottom at each of the three stations. Model predictions (currents, temperature, and salinity) were in good agreement luith available data using relative error, root mean square error, linear regression analysis, and error coefficient of variation as quantitative evaluation criteria. Model predictions showed that circulation in the bay is generally dominated by the tide, except in the lower reaches of the Taunton River where density induced, two layer flow becomes important. Tlie thermal structure of the bay is dominated by the power plant discharge in the northwestern section of the bay and othenvise by natural atmospheric heating and cooling. Thermal stratification near the power plant is principally dependent on the discharge plume. It is strongest and most wide spread on ebb tide along the central axis of the plume and weaker during flood tide when the plume is confined to the near shore area