Numerical Investigation of the Impact of Calcasieu Ship Channel on the Hydrodynamics and Water-Substance Transport in Calcasieu Lake and Surrounding Wetlands

Calcasieu Lake is located in the heart of the Chenier Plain coastal wetland area, which is a geographical region that extends from Vermillion parish of Louisiana to Chambers county of Texas. On the north side of Calcasieu Lake, there is a heavily industrialized area and the Port of Lake Charles. A ship channel, Calcasieu Ship Channel, was constructed through the Calcasieu Lake connecting Lake Charles and Gulf of Mexico for safe navigation of crude oil, gasoline, and other products for local industries. Due to the increased size of the vessel, the ship channel was widened and deepened in recent years. However, the presence of the wide, deep ship channel made significant impact on the hydrodynamics and water-substance transport in the lake and surrounding wetlands. The impact includes frequent flooding and abnormal salinity, nutrient and pollutant concentrations. In this study, numerical simulations were conducted to study the impact. An unsteady depth-averaged shallow water equation set was implemented to simulate the hydrodynamics (1–4), while for the scalar particulate phase an unsteady depth-averaged scalar transport equation was implemented for the water-substance transport simulations. The results of flow phase agreed well with measurement data (5). The simulations with and without the ship channel were conducted and the results were compared to study the impact.