Project Title: TIME and SICS Modeling of Surface Water and Interactions with Ground Water

Project Start Date: 10/00 Project End Date: 9/06

Web Sites: time.er.usgs.gov, sofia.usgs.gov/projects/time/, sofia.usgs.gov/projects/sheet_flow/

Location (Subregions, Counties, Park or Refuge): Southern Everglades and Florida Bay; Miami-Dade County; Everglades National Park

Funding Source: USGS's Greater Everglades Science Initiative (PBS)

Principal Investigator(s): Dr. Eric Swain

Project Personnel: Melinda Wolfert

Supporting Organizations: Everglades National Park; Army Corps of Engineers; South Florida Water Management District

Associated / Linked Projects: Across Trophic Level System Simulation (ATLSS); Canal and Wetland Flow/Transport Interaction, Effect of Wind on Surface Water Flows; Everglades ET measurement and modeling, Flow Velocity and Water Level Transects; Freshwater Flows into Northeastern Florida Bay; Geophysical Studies of the Southwest Florida Coast; Ground Water Flow and Transport for the SICS and TIME Models; Groundwater-Surface Water Interactions and Relation to Water Quality in the Everglades; High Accuracy Elevation Data Collection; High-Resolution Bathymetry of Florida Bay; Southwest Florida Coastal and Wetland Systems Monitoring; Vegetative Resistance to Flow in the Everglades

Overview & Objective(s): In this investigation, multidimensional coupled surface-water/ground-water models have been developed for the southern Florida wetlands and offshore area. The initial surface-water model, the SICS model, represents the southeast coastal region with the two-dimensional dynamic wave model SWIFT2D. The coupling with the SEAWAT three-dimensional ground-water model allows leakage to be represented with salinity transfer included. In order to represent regional restoration scenarios, the SICS model is to be linked via boundary water levels to the regional South Florida Water Management Model. The same modeling system is in the process of being expanded to the west and north to include the TIME domain. This encompasses more of the structural controls in the area and allows for the representation of Shark Slough flows. Field collection of nutrient data will provide essential information for future modeling developments.

Status: The report on the SICS surface-water model has been submitted for final approval. The coupled SICS model has a seven-year simulation period producing good representations of field data. The user's manual for SWIFT2D is currently in first draft form. The development of boundary conditions from the regional water-management model has been completed for all water-level boundaries but some discharge boundary conditions remain to be resolved. The development of the surface-water and ground-water components of TIME is nearly complete and the coupling of the two systems is to follow.

Recent & Planned Products: Two abstracts, a presentation, and a poster were developed for the Joint Conference on the Science and Restoration of the Greater Everglades and Florida Bay Ecosystem, April 13-18, 2003. A book chapter in "Coastal Aquifer Management," is also expected for release in September 2003. The report on the SICS surface-water model is planned for approval before the end of FY 2003. The user's manual for the SWIFT2D code should be ready for publication by mid-2004.

Relevance to Greater Everglades Restoration Information Needs: This coupled numerical model will continue to be a crucial decision support tool. The flows to the south and southeast coasts, along with salinity transport for existing and restoration scenarios will be generated for input to ecological models and hydrodynamic models of Florida Bay and the west coast.

Key Findings:

• The coupling of the dynamic surface-water model with a three-dimensional ground-water model allows for better representation of coastal salinity by more accurate representation of leakage exchange.
• Surface-water flow directions change in lower Taylor Slough from a southwest direction, the orientation of the Slough, to a southeastern direction towards Joe Bay. The model shows that this is because the shorter distance from Taylor Slough to Joe Bay induces the highest hydraulic gradient.
• There is multiple exchanges of ground water and surface water as flow proceeds southward through the SICS area. Ground water discharges to surface water as it rises above a salt-water wedge; surface water recharges to ground water as it impounds at the coastal embankment.