A Coupled Surface Water and Ground-Water Model to Simulate Past, Present, and Future Hydrologic Conditions in DOI Managed Lands

Project Investigator: Melinda Lohmann Project Personnel: Eric Swain, Chris Langevin, John Wang Project Start Date: 2006 End Date: 2009 Recent Funding: (FY08) ENP CESI, USGS GE PES, SFWMD, DOI Landscape, (FY07) ENP CESI, USGS GE PES, SFWMD, DOI Landscape Work Plans Project Summaries Metadata Publications

Summary

Objectives of this project are 1) to update and reconfigure the FTLOADDS modeling code; and, 2) to develop a comprehensive model by utilizing the established USGS TIME model application of the southern Everglades and linking it to a coupled surface and ground water model application of Biscayne Bay that is currently in development.

The USGS developed a coupled surface-water/ground-water numerical code known as the Flow and Transport in a Linked Overland/Aquifer Density-Dependent System (FTLOADDS) to represent the surface water and ground-water hydrologic conditions in south Florida, specifically in the Everglades. The FTLOADDS code combines the two-dimensional hydrodynamic surface-water model SWIFT2D, the three-dimensional ground-water model SEAWAT, and accounts for leakage and salt flux between the surface water and ground water. The code was then applied to two major testing regions: 1) the Southern Inland and Coastal Systems (SICS) model domain and 2) the Tides and Inflows in the Mangroves of the Everglades (TIME) model domain. The first application used code versions 1.0 and 1.1 which only utilized the SWIFT2D surface-water code. Later applications in the SICS area used version 2.1 where SWIFT2D was coupled to the SEAWAT groundwater model code. The second domain, TIME, utilizes the enhanced version 2.2 code, which includes enhancements to the wetting and drying routines, changes to the frictional resistance terms applications, and calculations of evapotranspiration. In 2006, FTLOADDS was modified again to represent Biscayne Bay and surrounding areas. The first objective of this project is to update and reconfigure the FTLOADDS modeling code to include all version modifications and enhancements in order to provide an easier transition for the coupling of models.

The second and principal objective of this project is to develop a comprehensive model by utilizing the established USGS TIME model application of the southern Everglades and linking it to a coupled surface and ground water model application of Biscayne Bay that is currently in development. This will provide one large sub-regional model that will give an integrated comprehensive assessment of how different scenarios will affect water flows in both Everglades National Park and Biscayne National Park. Once calibrated, additional simulations will be performed to estimate predevelopment hydrologic conditions and to predict hydrologic conditions under one or more of the proposed restoration alternatives, using inputs from the Natural Systems Model (NSM) and the South Florida Water Management Model (SFWMM).

Work Plans

• 2007
• 2008

Project Summaries

• 2007

Metadata

• A Coupled Surface Water and Ground-Water Model to Simulate Past, Present, and Future Hydrologic Conditions in DOI Managed Lands (project metadata)

Publications

Open File Reports

• U.S. Geological Survey Science Support Strategy for Biscayne National Park and Surrounding Areas in Southeastern Florida (OFR 2007-1288, available from the U.S. Geological Survey website)