SOFIA - OFR 02-204: T-sheets: Florida Everglades

Conversion of Historical Topographic Sheets (T-sheets) from Paper to Digital Form: Florida Everglades and Vicinity

By: Thomas J. Smith III¹ , Ann M. Foster², Peter R. Briere³, John W. Jones⁴, and Carson Van Arsdall⁴

Introduction:

The United States Congress has mandated a $7.8 billion dollar restoration of the Greater Everglades Ecosystem. The restoration is being guided by the Comprehensive Everglades Restoration Plan (CERP). Numerous federal, State of Florida and local agencies are involved in the restoration process as are private, not for profit non-governmental organizations.

A foundation for Everglades restoration must be a clear understanding of the pre-drainage south Florida landscape (Davis et al. 1994, Fennema 1994). Knowledge of the spatial organization and structure of the pre-drainage landscape communities (mangrove forests, marshes, sloughs, wet prairies, pinelands, etc.) is necessary to provide potential endpoints, restoration goals and performance measures to gauge restoration success.

Analyses of information contained in historical aerial photographs of the Everglades can aid in this endeavor. For example, the earliest known aerial photographs are from the mid to late 1920s and resulted in the production of what are called T-Sheets (for Topographic Sheets) for the coasts and shorelines of far south Florida. Importantly, the position of the boundary between differing vegetation communities (the ecotone) can be accurately measured. If followed through time changes in the position of these ecotones could potentially be used to judge effects of drainage on the Everglades ecosystem and also to monitor restoration success.

The Florida Caribbean Science Center (FCSC), a center of the U.S. Geological Survey's (USGS) Biological Resources Division (BRD), in collaboration with the Mapping Applications Center (MAC) of the National Mapping Division (NMD) has created digital versions of existing topographic survey (T-sheets) for the Florida Everglades region. These digital files are available on this CD-ROM in a manner designed to facilitate access to the product by those intending to integrate the data with other spatial data, particularly those interested in the impacts of global climate change and land use change on coastal ecosystems.

Approximately 30 scanned T-sheets have been georeferenced in the Florida Everglades region. These georeferenced maps were combined, resulting in a single, georeferenced mosaic also available on this CD-ROM. Due to space constraints, the georeferenced files (ex. 4371_geo.tif) are located in a compressed file. Uncompressed, unreferenced images (ex. t-4371.tif) included on the CD are useful for quick access to the data via many basic imaging software packages.

The T-sheets are detailed survey maps issued by the National Oceanic and Atmospheric Administration's (NOAA) National Ocean Service (NOS), formerly the U.S. Coast and Geodetic Survey. These maps were produced to provide coastlines for use on navigation charts and contain survey marker locations, lines of latitude and longitude, and a representation of vegetation inland from the coast. Most of the South Florida maps on this CD are at a 1:20,000 scale, excepting 3 maps at 1:10,000 in the Sanibel Island vicinity not included as part of the digital mosaic. The maps are based on aerial photography from 1925 to 1935. The maps were published upon completion, some as early as 1931 and others based on supplemental survey data completed in October, 1940.

Acknowledgements:

Funding from the USGS Place-Based Studies program to the senior author under the project Interrelation of Everglades hydrology and Florida Bay dynamics to ecosystem processes and restoration in south Florida' helped make this report possible. Additional funding came from the Critical Ecosystems Studies Initiative administered by Everglades National Park for the project "Vegetation dynamics in land-margin ecosystems: The mangroves of south Florida" and is gratefully acknowledged. R. Johnson, W. Perry, D. Buker and T. Mullins of the South Florida Natural Resources Center at Everglades National Park provided access to the Park's aerial photographic archives.Comments on earlier versions of the report were provided by A. Frick and H. Mounts.

Disclaimer:

This report was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of the information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights.

Although the data published herein has been reviewed by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related material. Publication and distribution of these data should not be construed to constitute any such warranty and no responsibility is assumed by the USGS in the use of these data or related materials.

Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply endorsement, recommendation, or favor by the United States Government or any agency thereof.

Literature Cited:

Davis, S.M., L.H. Gunderson, W.A. Park, J.R. Richardson & J.E. Mattson.1994. Landscape dimension, composition, and function in a changing Everglades landscape. Pgs. 419-443 In Davis, S.M. & J.C. Ogden. Everglades: The ecosystem and its restoration. St. Lucie Press, Delray Beach, FL.

Fennema, R.J., C.J. Neidrauer, R.A. Johnson, T.K. MacVicar & W.A. Perkins. 1994. A computer model to simulate natural Everglades hydrology. Pgs. 249-290 In Davis, S.M. & J.C. Ogden. Everglades: The ecosystem and its restoration. St. Lucie Press, Delray Beach, FL.

Quote this report as:

Smith, T.J., III, A.M. Foster, P.R. Briere, J. W. Jones & C. R. van Arsdall. 2002. Conversion of Historical Topographic Sheets (T-Sheets) to Digital Form: Florida Everglades and Vicinity. U.S. Geological Survey, Open File Report 02-204.