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Project Summary Sheet
Fiscal Year 2006 Study Summary Report
Project Title: High Accuracy Elevation Data Collection Project
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 used for ecosystem restoration.
Status: All Interagency Agreement commitments for FY06 were met for Airborne Height Finder (AHF) topographic surveys. Seven AHF field campaigns were conducted throughout the year. A total of 2220 three-dimensional measurements were made covering the East of Lone Palm Head and South of Deem City USGS 7.5 minute topographic quadrangles within Water Conservation Area 3 (WCA-3). AHF surveys are currently being conducted in the Lake Okeechobee littoral zone, funded by the South Florida Water Management District. The fieldwork for this effort will be completed this fiscal year. The project also continued to perform static GPS surveys to accurately geoposition water level gages throughout the Everglades. Five additional USGS Everglades Depth Estimation Network (EDEN) gages were surveyed this year. Further, Version 2 of the Gage Gazetteer was completed and demonstrated at this year's GEER Conference. These gages are geopositioned to within ± 2 centimeters as referenced to NAVD88 in terms of vertical accuracy.
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 product being developed by this project is a 400-meter topographic grid with very accurate latitude, longitude, and height values that define the topography of the Everglades. The data are organized by USGS 7.5 minute topographic quadrangles and are posted on the South Florida Information Access website (http://sofia.usgs.gov). To date, there are 70 files posted on the SOFIA web site for data distribution. Another major accomplishment has been the surveying of 142 water level gages distributed throughout the Everglades. The U. S. Geological Survey Gazetteer of Everglades Gage Sites - Second Edition was released this year and describes every water level gage surveyed in the Greater Everglades by the USGS, Eastern Geographic Science Center, since 1997. The second edition of the gazetteer includes 38 newly surveyed gage sites since the first edition was released. The gazetteer contains a table of gage sites whereby the user clicks on a name and a data sheet is displayed. The data sheet contains the 3-D position, detailed description of the reference mark, and a photograph of the gage site.
Plans for FY07 include AHF surveys of the remaining portion of Water Conservation Area-3 (North of Lone Palm Head and Lone Palm Head USGS 7.5 minute topographic quadrangles) as well as filling in data gaps in the Horseshoe Head and West of Horseshoe Head quadrangles.
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.
Key Finding: The AHF system is the superior technology for conducting a wide-area topographic survey of the Florida Everglades where the terrain surface being measured is inundated by surface water and thick vegetation.
U.S. Department of the Interior, U.S. Geological Survey
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Last updated: 04 September, 2013 @ 02:08 PM(TJE)