Hydrodynamic modeling of the Western Mississippi Sound using a linked model system

Abstract

This study addresses the development of a hydrodynamic model for the Western Mississippi Sound, in the Gulf of Mexico. The study site consists of a riverine part that includes the Lower Pearl River basin and an estuarine part that includes the Western Mississippi Sound. In order to study the driving mechanisms of this area, two hydrodynamic models were developed and linked; one for the Lower Pearl River, and another for the Western Mississippi Sound. Both models are driven by meteorological, flow, and pressure boundary conditions and were developed using the Visual Environmental Fluid Dynamic Code. Both models simulate flow, water surface elevation, temperature, and salinity. Outputs from the Lower Pearl River model are linked to the Western Mississippi Sound model. The Lower Pearl River model was calibrated for an 8-year period, and validated for a 9-year period. The Western Mississippi Sound model was calibrated and validated for two separate periods, each of 2-year duration.The outputs of both models are discussed using several graphical and statistical measures. The results of these measures demonstrate that the linked hydrodynamic models are able to represent riverine flow and estuarine circulation by accurately simulating flow, water surface elevation, temperature, and salinity. The linked model system developed in this investigation has the ability to be integrated with water quality and habitat suitability models. Future work will involve using the model system to study the ecological impacts of hydrologic variability, such as flooding, flood control, and/or water diversions in the Western Mississippi Sound.