A nested three dimensional numerical modeling application was developed to determine the fate of pathogen indicators in Lake Pontchartrain discharged from its tributaries. To accomplish this, Estuarine, coastal and ocean model with sediment (ECOMSED) was implemented to simulate various processes that would determine the fate and transport of fecal coliform bacteria in the lake. The processes included hydrodynamics, waves, sediment transport, and the decay and transport of the fecal coliforms. Wind and tidal effects were accounted along with the freshwater inflows. All the components of the modeling application were calibrated and validated using measured data sets. Field measurements of the conventional water quality parameters and fecal coliform levels were used to calibrate and validate the pathogen indicator transport. The decay of the fecal coliforms was based on the literature and laboratory tests. The sediment transport module was calibrated based on the satellite reflectance data in the lake. The north shore near-field model indicated that the fecal coliform plume can be highly dynamic and sporadic depending on the wind and tide conditions. It also showed that the period of impact due to a storm event on the fecal coliform levels in the lake can be anywhere from 1.5 days for a typical summer event to 4 days for an extreme winter event. The model studies showed that the zone of impact of the stormwater from the river was limited to a few hundred meters from the river mouth. Finally, the modeling framework developed for the north shore was successfully applied to the south shore of Lake Pontchartrain to simulate fate and transport of fecal coliforms discharged through the urban stormwater outfalls.
| Identifer | oai:union.ndltd.org:uno.edu/oai:scholarworks.uno.edu:td-1359 |
| Date | 20 January 2006 |
| Creators | Chilmakui, Chandra Sekhar |
| Publisher | ScholarWorks@UNO |
| Source Sets | University of New Orleans |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of New Orleans Theses and Dissertations |
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