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GIS Data & Maps: Digital Land Cover (LC1534-97)
Description and Disclaimer
Landsat Thematic Mapper (TM) satellite data was used to classify the landscape following protocols developed by the Coastal Change Analysis Program (CCAP) of the National Oceanic and Atmospheric Administration (NOAA). One satellite scene (TM 1534; dated July 14, 1997) capturing a major portion of Virginia's tributaries to the western shore of the Chesapeake Bay was classified using image processing techniques, and Erdas Imagine® (v.8.0/8.2) software. Approximate coordinates (UTM zone 18, NAD83) of the scene are:
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NW corner: x = 238265; y = 4255857
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NE corner: x = 414744; y = 4219012
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SE corner: x = 368039; y = 4042852
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SW corner: x = 191646; y = 4079706
The classification includes 14 different land cover classes. They are
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high intensity developed
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low intensity developed
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cultivated lands
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grass lands
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deciduous forest
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evergreen forest
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mixed forest
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scrub-shrub
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palustrine forest
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palustrine scrub-shrub
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palustrine emergent
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estuarine emergent
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bare land
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water
A signature library of samples collected in the field was developed to assist the classification. More than 1,400 points provided a spectrum of signatures for each land cover type throughout the landscape. Isodata clustering was performed iteratively. Collateral data used to assist in the classification include: the most recent digital National Wetlands Inventory data provided by the Fish and Wildlife Service; digital road network provided by the US Census Bureau; VIMS Tidal Marsh Inventory data; digital ortho quarter quadrangles (DOQQ); aerial photography from the National Aerial Photography Program (NAPP) of the USGS; and earlier classified image data for the same area. Collateral data help strengthen and verify results throughout the classification process. Upon completion, more than 800 sites were visited across the geographic boundaries of the scene to ground-truth the final iteration.
Landsat TM data has a reported pixel resolution of 30 meters. This means it is difficult to resolve features less than 30 meters. Although sub-pixel analysis was performed during the classification, the 30 meter resolution limitation pertains to the final classified data as well.
The final product is available as an ArcInfo grid file. LC1534-97 is a product of the Comprehensive Coastal Inventory Program. This product was 50% ($55,759) funded by the Virginia Coastal Resources Management Program at the Department of Environmental Quality through Grant # NA870Z0253-01 of the National Oceanic and Atmospheric Administration, Office of Ocean and Coastal Resource Management under the Coastal Zone Management Act of 1972, as amended.
The metadata file which accompanies this coverage defines attribute accuracy, data development, and any use restriction which pertain to the data. The data can be downloaded at this site. In doing so, the users agree to all conditions outlined in the disclaimer. CCI continues to seek funds to expand this classification, and complete the Virginia portion of the Chesapeake Bay.
The Comprehensive Coastal Inventory Program (CCI) provides these data with the understanding that it is not guaranteed to
be correct or complete, and conclusions drawn from the data set are the sole responsibility of the user.
Every attempt has been made to ensure that these data and the documentation are reliable and accurate. Neither CCI, nor the Virginia Institute of Marine Science (VIMS) assume liability for any damages caused by inaccuracies in the data or documentation, or as a result of failure of the data to perform in a particular manner. CCI and VIMS make no warranty, express or implied, as to the accuracy, completeness, or utility of this information, nor does the fact of distribution constitute a warranty.
Individuals who download these data agree to the following, and understand the limitations defined:
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Integration of these data into other products requires proper citation. Proper citation for this coverage is:
"Center for Coastal Resources Management, Digital Land Cover - LC1534 - 97, 2000. Comprehensive Coastal Inventory Program, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia, 23062."
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Use of these data in map publications, either digital or hardcopy, requires proper citation, and inclusion of the CCI logo.
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CCI is not responsible for misuse of these data.
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CCI does not oversee or assume responsibility for alterations to this product by users.
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CCI may not address specific questions from users who received the data through another party.
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Distribution of these data is not restricted. CCI, however, recommends metadata file(s) always remain with the data.
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CCI encourages noticeable errors be reported to CCI contact person identified in the metadata file.
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