Julie C. Bernier
2015
Shoreline Positions and Sand Extents Derived from Landsat Satellite Imagery, Assateague Island to Metompkin Island, Maryland and Virginia, 1984 to 2014
Vector digital data
http://pubs.usgs.gov/ds/0968/downloads/landsat_a2a_sand_shrln_final.zip
Julie C. Bernier
Steven H. Douglas
Joseph F. Terrano
John A. Barras
Nathaniel G. Plant
Christopher G. Smith
2015
Land-Cover Types, Shoreline Positions, and Sand Extents Derived from Landsat Satellite Imagery, Assateague Island to Metompkin Island, Maryland and Virginia, 1984 to 2014
Multimedia presentation
U.S. Geological Survey Data Series
968
St. Petersburg, FL
U.S. Geological Survey
https://doi.org/10.3133/ds968
The U.S. Geological Survey has a long history of responding to and documenting the impacts of storms along the Nation’s coasts and incorporating these data into storm impact and coastal change vulnerability assessments. These studies, however, have traditionally focused on sandy shorelines and sandy barrier-island systems, without consideration of impacts to coastal wetlands. The goal of the Barrier Island and Estuarine Wetland Physical Change Assessment project is to integrate a wetland-change assessment with existing coastal-change assessments for the adjacent sandy dunes and beaches, initially focusing on Assateague Island along the Maryland and Virginia coastline. Assateague Island was impacted by waves and storm surge associated with the passage of Hurricane Sandy in October 2012, including erosion and overwash along the ocean-facing sandy shoreline as well as erosion and overwash deposition in the back-barrier and estuarine bay environments.
This report serves as an archive of data that were derived from Landsat 5 and Landsat 8 imagery from 1984 to 2014, including wetland and terrestrial habitat extents; open-ocean, back-barrier, and estuarine mainland shoreline positions; and sand-line positions along the estuarine mainland and barrier shorelines from Assateague Island, Maryland to Metompkin Island, Virginia. The geographic information system data files with accompanying formal Federal Geographic Data Committee (FGDC) metadata can be downloaded from http://pubs.usgs.gov/ds/0968/ds968_data.html.
This zip archive includes vector data representing shoreline positions and sand extents derived from 19 Landsat 5 Thematic Mapper (TM) and four Landsat 8 Operational Land Imager (OLI) image datasets from Assateague Island to Metompkin Island, Maryland and Virginia. For each image acquisition date, the Level 1 data products were stacked into composite 6-band (visible blue, green, and red; near infrared; and two short-wave infrared bands) image files and converted to at-sensor radiance and top-of-atmosphere reflectance. Adjacent scenes (Worldwide Reference System 2, path 14 row 33 and path 14 row 34) were mosaicked to a single image and then clipped to the study area extent. Seven land-cover classes (water, wet marsh, marsh, forested, mixed vegetation, vegetated bare earth, and bare earth) were derived for each image acquisition date using a hybrid classification approach to minimize misclassification of small interior water bodies and tidal channels with surrounding marsh environments. Vector line files representing the continuous inland extent of sand behind the open-ocean shoreline, the ocean-facing sea shoreline, the back-barrier island shoreline, the estuarine mainland shoreline, and back-barrier estuarine marsh islands were extracted from the thematic land-cover datasets.
Information about the Landsat missions, sensor and band specifications, Level 1 data products, and data acess can be found at http://landsat.usgs.gov/index.php.
19841124
19890428
19891005
19940426
19941104
1990510
19991118
20040405
20041115
20050611
20051102
20070516
20070617
20080416
20081126
20090318
20110425
20110714
20110831
20130414
20130905
20140401
20141026
Ground condition
None planned
-75.590337
-74.993480
38.327347
37.739426
USGS Metadata Identifier
USGS:f523a58b-36d5-404f-a542-09e3b6330098
None
Landsat
Barrier island
Estuarine
Coastal
Unsupervised classification
Land cover
Shoreline
Back-barrier
Sand extent
Barrier Island and Estuarine Wetland Physical Change Assessment
U.S. Geological Survey
USGS
Geographic Names Information System (GNIS)
Maryland
Virginia
Assateague Island
Chincoteague Bay
None
The U.S. Geological Survey requests that it be acknowledged as the originator of this dataset in any future products or research derived from these data.
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center
Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.2.2.3552
Kristy K. Guy
2015
Back-island and open-ocean shorelines, and sand areas of Assateague Island, Maryland and Virginia, April 12, 1989, to September 5, 2013
Multimedia presentation
U.S. Geological Survey Data Series
928
St. Petersburg, FL
U.S. Geological Survey
https://doi.org/10.3133/ds928
Landsat standard data products, processed using the Level 1 Product Generation System (LPGS), were downloaded from the USGS Earth Resources Observation and Science (EROS) Center data archives.
Even after using a hybrid classification approach, some areas that were classified as wet marsh in the final thematic raster dataset appeared, upon visual inspection, to include submerged aquatic vegetation and submerged sand flats that would be more appropriately classified as open water. These ambiguities are not consistent through time but most commonly occur in Sinepuxent Bay south of Ocean City Inlet, north of Green Run Bay and Pirate Islands, in impoundments behind Chincoteague Island, and at Chincoteague Inlet. Similarly, in some instances, areas that were classified as water in the final thematic raster dataset were interpreted as wet sand on visual inspection. This most commonly occurs along the narrowest part of Assateague Island south of Ocean City Inlet, at the Tom’s Cove spit, and along Metompkin Island. Additionally, some near-shore estuarine areas exhibit “speckling” caused by misclassification of isolated higher reflectance pixels within the water body. No manual cleaning of open-water speckling or potentially misclassified pixels was performed.
The primary sand lines represent the continuous inland extent of sand behind the open-ocean shoreline; lines representing sand extents or vegetation “islands” larger than eleven pixels (about 10,000 m2) were also included. Similarly, the primary back-barrier shoreline represents the continuous back-barrier land extent; however, shorelines around back-barrier marsh islands larger than 10,000 m2 were also included in the shoreline datasets. Line features were manually edited on the basis of visual comparison with both the original Landsat image and the final thematic raster dataset; for example, classified land areas that were visually interpreted as open water were excluded from the back-barrier shoreline or back-barrier island extents.
Nineteen Landsat 5 Thematic Mapper (TM) and four Landsat 8 Operational Land Imager (OLI) image acquisition dates were selected for analysis. Image acquisition dates correspond to 5-year intervals beginning in 1984 supplemented with additional images from intervening years for which high-resolution aerial photography was also analyzed (Guy, 2015). If available, spring (April preferred) and late fall (November preferred) image acquisition dates were used for each analysis year. The spring and fall images were supplemented with additional scenes corresponding to aerial photography acquisition dates (Guy, 2015). A gap in imagery dates from August 31, 2011 to April 14, 2013, corresponding to the decommissioning of the Landsat 5 TM mission and the first data available from the recently launched Landsat 8 OLI mission. Data from the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) satellite are available for this time period; however, data gaps exist over the study area in all Landsat 7 images acquired since May 2003 due to the failure of the scan line corrector early in May 2003, limiting the use of these Landsat 7 data in quantitative land-change analyses.
Geodetic accuracy of the Standard Terrain Correction (Level 1T) data product depends on the accuracy of the ground control points and the resolution of the DEM used.
Each Landsat Level 1 data product was stacked into a composite multi-band image file using Intergraph Corporation ERDAS IMAGINE 2014 software. The six reflective bands (visible blue, green, and red; near infrared; and two short-wave infrared bands) for each sensor were stacked and used in subsequent processing and analyses.
2014
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
The composite multi-band image files were converted to at-sensor radiance and top-of-atmosphere (TOA) reflectance using Intergraph Corporation ERDAS IMAGINE 2014 software. Radiometric processing reduces scene-to-scene variability due to gain changes between scenes or differences in solar zenith angles, exoatmospheric solar irradiance, and the earth-sun distance resulting from different acquisition dates and times.
2014
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
For each image acquisition date, adjacent scenes (Worldwide Reference System 2, path 14 row 33 and path 14 row 34) were mosaicked to a single image and clipped to the study area extent.
2014
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
Image classification was performed using Intergraph Corporation ERDAS IMAGINE 2014 software. A hybrid classification approach was used to minimize misclassification of small interior water bodies and tidal channels with surrounding marsh environments:
(1) A 3×3 (pixel) edge enhancement convolution filter was applied to the radiometrically corrected, mosaicked images to enhance small water features;
(2) Unsupervised classification was performed on the edge-enhanced image to identify and extract water areas;
(3) Water areas from (2) were masked from the non edge-enhanced image and unsupervised classification of the remaining pixels was grouped into seven classes (water, wet marsh, marsh, forested, mixed vegetation, vegetated bare earth, and bare earth); and
(4) Results of (2) and (3) were merged to generate a final thematically classified raster dataset.
2015
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
Line feature classes representing open-ocean, back-barrier, and estuarine mainland shoreline positions and beach/sand-line positions were generated from from the final thematic raster datasets using the Raster to Polygon and Polygon to Line tools in ArcGIS 10.2.
2015
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20201013
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Vector
Universal Transverse Mercator
18
0.9996
-75.0
0
500000.0
0.0
Coordinate pair
0.001
0.001
Meters
D WGS 1984
WGS 1984
6378137.0
298.257223563
lt5_sand_shrln_final.gdb
Esri file geodatabase containing 4 vector line datasets representing sand extents and sea, back-barrier, and estuarine mainland shoreline positions derived from Landsat 5 classified imagery
USGS
lc8_sand_shrln_final.gdb
Esri file geodatabase containing vector line datasets representing sand extents and sea, back-barrier, and estuarine mainland shoreline positions derived from Landsat 8 classified imagery
USGS
FID
Internal feature number
Esri
Sequential unique whole numbers that are automatically generated
Shape
Feature geometry
Esri
Coordinates defining the features
DATE
Image acquisition date
USGS
Image acquisition date written as yyyymmdd
LENGTH_m
Length of line segment, in meters
USGS
210
110700
meters
30 meters (1 pixel)
TYPE
Line segment type
USGS
sand line
Inland extent of sand behind the open-ocean shoreline
USGS
sand island
Sand extents (“islands”) inland of or isolated from the continuous sand line, larger than eleven pixels (about 10,000 m2)
USGS
vegetation island
Vegetation extents (“islands”) seaward of the continuous sand line, larger than eleven pixels (about 10,000 m2)
USGS
sea shoreline
Ocean-facing sea shoreline
USGS
back-barrier shoreline
Estuarine-facing back-barrier shoreline
USGS
estuarine mainland
Estuarine-facing mainland shoreline
USGS
marsh island
Estuarine marsh islands larger than eleven pixels (about 10,000 m2)
USGS
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
Downloadable data
This publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
Esri file geodatabase
10.2.2
Vector dataset
This zip file contains two file geodatabases, containing vector line datasets representing sand extents and sea, back-barrier, and estuarine mainland shoreline positions derived from Landsat 5 and Landsat 8 classified imagery, respectively, and this metadata.
Unzip
0.58
http://pubs.usgs.gov/ds/0968/downloads/landsat_a2a_sand_shrln_final.zip
None, if obtained online
These file geodatabase raster datasets were created using Esri ArcGIS version 10.2.2 and can be opened using Esri ArcGIS version 10.0 or higher; these data may also be viewed using the free GIS viewer ArcGIS Explorer.
20201013
U.S. Geological Survey
Julie Bernier
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
jbernier@usgs.gov
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
None
The U.S. Geological Survey requests that it be acknowledged as the originator of this dataset in any future products or research derived from these data.
None
Unclassified
None