Project Title: High Accuracy Elevation Data Collection Project
Project Start Date: FY 1995 Project End Date: To be determined
Web Sites: http://sofia.usgs.gov
Location (Subregion & County): Everglades National Park, Water Conservation Areas, Greater Everglades
Funding Sources: USGS Greater Everglades Priority Ecosystems Science (PES) initiative, NPS CESI Program, SFWMD, CERP/MAP
Principal Investigator: Greg Desmond, 703/648-4728, gdesmond@usgs.gov
Project Personnel: Vince Caruso, Ed Cyran, Gary Freeman, Bob Glover, Chuck Henkle, Gordon Shupe
Supporting Organizations: Everglades National Park, South Florida Water Management District
Associated / Linked Projects: TIME, SICS, ATLSS, Vegetative Resistance to Flow, Fresh Water Flows into Florida Bay, Water Flows and Nutrient Loads to the SW Coast, other agencies and projects that require accurate elevation data.

Overview & Objective: Modeling of sheet flow and water surface levels in the Florida Everglades is very sensitive to changes in elevation due to its expansive and extremely low relief terrain. This project is applying state-of-the-art Global Positioning System (GPS) technology to perform topographic surveys that meets a vertical accuracy specification of ±15 centimeters (6 inches). The objective is to complete a wide-area regional topographic survey that will provide elevation data to parameterize hydrologic and ecological models.

Status: Six surveying field campaigns were conducted in FY04. All work defined within the SFWMD/USGS Joint Funding Agreement, C-C20301A, has been completed and all data sets have been delivered to SFWMD as well as having been posted on the SOFIA web site. This work included the topographic surveys of Loxahatchee National Wildlife Refuge, and the digital elevation models (DEMs) have been posted on the SOFIA website. Work for Water Conservation Area 2 (WCA-2) being funded by CERP/MAP has been planned and fieldwork began in FY04 and will be completed in FY05.

Recent & Planned Products: The topographic surveys are being performed using differential GPS technology, and a USGS developed helicopter-based instrument known as the Airborne Height Finder (AHF). In some areas, the surveying has been accomplished using airboats. The primary products being developed by this project are Digital Elevation Models (DEM's) that define the topography of the Everglades. The DEM's are organized by USGS quadrangles and are posted on the South Florida Information Access website (http://sofia.usgs.gov) once approved for release. To date, there are 70 digital elevation model files posted on the SOFIA web site for data distribution. Project presentations were provided to the SFWMD, and the CERP AAT in FY04. A poster was also presented at the Loxahatchee Science Conference organized by FWS.

Another major accomplishment has been the surveying of USGS and NPS water level gages distributed throughout ENP. A database, or "gage gazetteer", of the gage sites has been produced. The gazetteer contains a table of gage sites whereby the user clicks on a name and a data sheet is displayed containing the 3-D position of the reference mark and a photograph of the gage site.

Relevance to Greater Everglades Restoration Information Needs: The project supports the restoration and resource management efforts by providing critical data for the parameterization of numerical hydrologic and ecological models. Water resources and land management decisions will rely heavily on the results of these simulation models. It is imperative to derive and use the most accurate elevation data available for the models to produce meaningful results.