ADVANCES AND APPLICATIONS OF HYDRODYNAMIC TRANSPORT MODELING COUPLED TO UNDERLYING GROUND-WATER FLOW IN SOUTHERN FLORIDA, USA

The Flow and Transport in a Linked Overland/Aquifer Density-Dependent System (FTLOADDS) is a simulator that couples a two-dimensional hydrodynamic code with a groundwater flow and salinity transport code. The capabilities of FTLOADDS address the unique hydrologic conditions in South Florida, such as the high surface-water/groundwater connectivity and dynamic coastal flow interactions. Models developed with the FTLOADDS simulator include the Tides and Inflows to the Mangrove Everglades (TIME), the Biscayne Southeastern Coastal Transport (BISECT), and the Ten Thousand Islands (TTI) model. These three different models show the capabilities and applicability of FTLOADDS to different types of hydrological problems in South Florida.

TIME is the first application to be widely used for simulating the dynamic coastal hydrology in Everglades National Park (Wang and others, 2007). Northern inflows to TIME were modified to represent the effects of regional hydrologic modifications planned for ecosystem restoration. The simulation supplies information to ecological models of species behavior and habitat. A model of coastal fish species (Cline and other, 2004) and an American Crocodile population model make use of TIME hydrologic output.

BISECT combines the areal data from the TIME model with data from a FTLOADDS model of the Biscayne Bay urban area. BISECT has been used by the Army Corps of Engineers to examine sea-level rise effects on urban flooding and salinity intrusion. Also, three seven-year BISECT simulations between the years 1926 and 1952 were produced for a multidisciplinary study to delineate coastal landscape changes. The 1926 Miami hurricane and other storm events were simulated and results compared with historic data such as aerial photography. Figure 1 shows a comparison of historic and contemporary inundation-duration statistics.

The TTI model simulates the hydrology of the Ten Thousand Islands area (Swain and Decker, 2009) to examine the effects of an ecosystem restoration project on local manatee habitats. A surface-water heat-transport component was added to the FTLOADDS code as water-temperature is important to manatee ecology. The TTI model is used to create boundary conditions for a small-scale three-dimensional surface-water salinity and heat-flow model of the Port of the Islands, a local manatee habitat, to determine factors that contribute to thermal inversions, as shown simulated in figure 2, which benefit the manatees.

References Cited

Cline, Jon C., Lorenz, Jerome J., and Swain, Eric D., 2004, Linking Hydrologic Modeling and Ecologic Modeling: An Application of Adaptive Ecosystem Management in the Everglades Mangrove Zone of Florida Bay: International Environmental Modelling and Software Society iEMSs 2004 International Conference, June 14-17 2004, University of Osnabrück, Germany.

Swain, E.D., and Decker, J.D., 2009, Development, Testing, and Application of a Coupled Hydrodynamic Surface-Water/Ground-Water Model (FTLOADDS) with Heat and Salinity Transport in the Ten-Thousand Islands/Picayune Strand Restoration Project Area, Florida: U.S. Geological Survey Scientific Investigations Report 2009-5146.

Wang, J, D., Swain, E.D., Wolfert, M. A., Langevin, C.D., James, D. E., and Telis, P. A., 2007, Applications of Flow and Transport in a Linked Overland/Aquifer Density Dependent System (FTLOADDS) to Simulate Flow, Salinity, and Surface-Water Stage in the Southern Everglades, Florida: U.S. Geological Survey Scientific Investigations Report 2007-5010.