Eric D. Swain¹ and Brad Stith^2
1U.S. Geological Survey, Florida Integrated Science Center, Fort Lauderdale, FL, USA
²U.S. Geological Survey, Florida Integrated Science Center, Gainesville, FL, USA

Numerical models of the surface- and ground-water systems in southern Florida have been constructed to examine local hydrology and transport phenomena, and to provide insight into the effects of restoration plans on the natural system. Numerical models of the southern Everglades use the FTLOADDS (Flow and Transport in a Linked Overland/Aquifer Density-Dependent System) code to model the hydrologic system. The FTLOADDS application TIME (Tides and Inflows in the Marshes of the Everglades) utilizes the code capability for salinity transport to account for the effect of density variations on flow in Everglades National Park and adjacent coastal areas.

Salinity is an important factor in manatee migration patterns and survivability because of their need for fresh drinking water. Manatees also require sufficiently warm water temperature to prevent hypothermia. Salinity and temperature modeling in the southern Everglades will be combined with existing manatee tracking and response information to delineate the effects of hydrologic factors on manatee migration and survivability. The FTLOADDS code has the capability to compute heat transport for water-temperature modeling, and is being modified for use in the TIME application. As part of the development of TIME and the preceding application SICS (Southern Inland and Coastal Systems), the computation of evapotranspiration was incorporated into the FTLOADDS code. The current modifications will link the latent heat computation for evapotranspiration with the heat transport algorithm for more consistent computations. Modified water-delivery scenarios can then be simulated and the resulting effects examined.

In the Ten Thousand Islands area, local thermal inversions have been observed that affect the manatee population and its migration patterns. Field studies indicate that salinity is a strong factor in maintaining this unusual type of temperature stratification. This phenomenon occurs in the inland part of the Ten Thousand Island area, which is characterized by natural and anthropogenic channels, and interspersed wetland areas. A FTLOADDS application specific to this area (and known as TTI) will be used to determine the causes of these temperature and salinity patterns. TTI will utilize methods identical to those developed for heat and salinity transport in the TIME application. The TTI application will be used to develop information and boundaries for a smaller scale three-dimensional model application to represent temperature and salinity stratification. Determining the dynamics of this system increases the ability to predict the factors affecting manatees and other species in these habitats.

Contact Information: Eric D. Swain U.S. Geological Survey, Florida Integrated Science Center, 3110 SW 9th Avenue, Fort Lauderdale, Florida 33315 USA, Phone: 954-377-5925, Fax: 954-377-5901, Email:edswain@usgs.gov

(This abstract is from the 2006 Greater Everglades Ecosystem Restoration Conference.)

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