Author(s): Z. Q. Deng; H. S. Jung
Linked Author(s): Zhiqiang Deng
Keywords: Lake Pontchartrain; Sediment plume; Dissolved oxygen; Water quality modeling
Abstract: Lake Pontchartrain is a 1632 km2 estuary receiving diverse urban and agricultural discharges. The overall goal of this paper was to assess spatial and temporal variations of water quality parameters in Lake Pontchartrain due to discharges of contaminated stormwater runoff from New Orleans. To that end, the Environmental Fluid Dynamics Computer Code was utilized to simulate patterns of water quality variation-driven by tides and winds in the Lake Pontchartrain, Louisiana, USA. To determine temporal and spatial variations in monthly mean dissolved oxygen (DO), the water depth is divided into three sigma-layers and HEM-3D is used. Temperature modeling was performed by considering daily averaged heat exchange between water surface and atmosphere. Simulation results show that the distribution of contaminated sediment is highly related to flow patterns caused by wind. For southeasterly wind, the sediment is distributed along the south shoreline of the lake and dispersion of sediment to the center of the lake is limited. For northerly wind, sediment showed the tendency to spread to the center of the lake but sediment concentrations are relatively low. Monthly mean dissolved oxygen (DO) concentration in April-August shows a strong stratification. The low DO zones are formed in deep water area of the lake near south shorelines of the lake.
Year: 2011