Terrestrial and Submerged Aquatic Vegetation Mapping in Fire Island National Seashore Using High Spatial Resolution Remote Sensing Data

Abstract

The vegetation communities and spatial patterns on the Fire Island National Seashore are dynamic as the result of interactions with driving forces such as sand deposition, storm-driven over wash, salt spray, surface water, as well as with human disturbances. We used high spatial resolution QuickBird-2 satellite remote sensing data to map both terrestrial and submerged aquatic vegetation communities of the National Seashore. We adopted a stratified classification and unsupervised classification approach for mapping terrestrial vegetation types. Our classification scheme included detailed terrestrial vegetation types identified by previous vegetation mapping efforts of the National Park Service and three generalized categories of high-density seagrass, low-density seagrass coverages, and unvegetated bottom to map the submerged aquatic vegetation habitats. We used underwater videography, GPS-guided field reference photography, and bathymetric data to support remote sensing image classification and information extraction. This study achieved approximately 82% and 75% overall classification accuracy for the terrestrial and submnerged aquatic vegetations, respectively, and provided an updated vegetation inventory and change analysis for the Northeast Coastal and Barrier Network of the National Park Service.

Keywords:

• Fire Island National Seashore
• terrestrial vegetation mapping
• submerged aquatic vegetation mapping
• remote sensing
• under-water videography

Acknowledgements

This study was funded by the Inventory and Monitoring Program of the Northeast Coastal and Barrier Network of the National Park Service. We appreciate the great support and field guidance by Diane Abell and Mike Bilecki of the Fire Island National Seashore. We wish to extend our special thanks to Beth Johnson and Charley Roman of the National Park Service for their insights and expertise. We thank Mark Finkbiener of the NOAA Coastal Services Center for providing us the 2003 true color ortho aerial photograph. Also, our special thanks to Raymond Keyes for providing vessel facilities during our underwater video exercises.

Notes

http://www.ngdc.noaa.gov/mgg/geodas/geodas.html

Environmental System Research Institute, Redland, California

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