| IMAGE.LandCover2006 | |
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Data format: SDE Raster Dataset File or table name: IMAGE.LandCover2006 Coordinate system: Universal Transverse Mercator Theme keywords: Land cover |
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Abstract:
High-resolution land cover for Washington, D.C. This land-cover map was developed for use in an Urban Tree Canopy (UTC) assessment for the city, and its classes reflect the specific needs of UTC protocols. Seven land-cover classes were mapped: Tree Canopy (1), Grass/Shrubs (2), Water (4), Impervious-Pavement (5), Impervious-Buildings (6), Impervious-Transportation (7), and Bare Earth (8). The primary source for this land-cover layer was 0.6-meter Quickbird color infrared (CIR) satellite imagery acquired on September 7, 2006. Other sources of data included planimetric GIS layers (buildings, roads, sidewalks, water, street trees, and wood areas). Land cover was mapped using an automated system centered on object-based image analysis (OBIA) techniques. The data were segmented into image objects and classified based on sets of rules in an iterative process.
No accuracy assessment was conducted, but the dataset was thoroughly reviewed at an approximate scale of 1:1,500. Manual corrections were incorporated directly into the OBIA output. |
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Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
High-resolution land cover for Washington, D.C. This land-cover map was developed for use in an Urban Tree Canopy (UTC) assessment for the city, and its classes reflect the specific needs of UTC protocols. Seven land-cover classes were mapped: Tree Canopy (1), Grass/Shrubs (2), Water (4), Impervious-Pavement (5), Impervious-Buildings (6), Impervious-Transportation (7), and Bare Earth (8). The primary source for this land-cover layer was 0.6-meter Quickbird color infrared (CIR) satellite imagery acquired on September 7, 2006. Other sources of data included planimetric GIS layers (buildings, roads, sidewalks, water, street trees, and wood areas). Land cover was mapped using an automated system centered on object-based image analysis (OBIA) techniques. The data were segmented into image objects and classified based on sets of rules in an iterative process. No accuracy assessment was conducted, but the dataset was thoroughly reviewed at an approximate scale of 1:1,500. Manual corrections were incorporated directly into the OBIA output.
Urban Tree Canopy (UTC) Assessment for Washington, D.C.
This land-cover map was completed by the University of Vermont's Spatial Analysis Laboratory with funding from a multi-state grant from the USDA Forest Service and incooperation with the USDA Forest Service's Northern Research Station. The UTC Assessment protocols were developed by the USDA Forest Service's Northern Research Station and the University of Vermont's Spatial Analysis Laboratory. UTC assessments have been conducted for numerous communities throughout the U.S. where the results have been instrumental in helping to establish UTC goals.
ground condition
Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.
81 Carrigan Drive
Aiken Room 220
University of Vermont Spatial Analysis Laboratory
No accuracy assessment was conducted, but the dataset was thoroughly reviewed at an approximate scale of 1:1,500. Manual corrections were incorporated directly into the dataset.
Valid raster dataset.
Complete for the City of Washington, D.C. based on boundary data supplied by the Washington, D.C. Urban Forestry Administration.
The land-cover map was developed from remotely-sensed data that meets National Map Accuracy Standards at a scale of 1:4,800.
Spectral data used to develop land-cover classes
Ancillary data used to aid classification of buildings. Original layer (BldgPly) developed by DC GIS (Washington, D.C. Office of the Chief Technology Officer).
Ancillary layer used to aid classification of municipal sidewalks. Original layer (SidewalkPly) develoiped by DC GIS (Washington, D.C. Office of the Chief Technology Officer).
Ancillary data used to aid classification of roads, parking, and driveways. Original layer (RoadPly) developed by DC GIS (Washington, D.C. Office of the Chief Technology Officer).
Ancillary data used to aid classification of water. Original layer (Waterbodies) developed by DC GIS (Washington, D.C. Office of the Chief Technology Officer).
Ancillary data used to aid classification of tree canopy located along city streets. Original layer (UFATrees) developed by the Washington, DC. Department of Transportation. The point locations representing individual trees in the original layer were buffered according to the DBH field, developing the following classes: DBH = 0, assumed crown diameter = 2.5 meters; DBH = 0 to 6 inches, assumed crown diameter = 4 meters; DBH = 6.1 to 18 inches, assumed crown diameter = > 10 meters; and DBH >18 inches, assumed crown diameter = 14 meters. Note that all street trees with TBOX_STAT = 'Open' or 'Proposed' were deleted prior to buffering.
Ancillary data used to aid classification of tree canopy. Original layer (WoodPly) was developed by DC GIS (Washington, D.C. Office of the Chief Technology Officer).
Object based image analysis (OBIA) using a rule-based expert system. Quickbird color infrared imagery (0.6-meter pixels) acquired on September 7, 2006 was the primary data source. Ancillary datasets (Buildings, Sidewalks, Roads, Water, Street Trees, Wooded Areas) were used to aid classification.
Manual corrections to land cover classification
Metadata imported.
Dataset copied.
Metadata imported.
Internal feature number.
ESRI
Land-cover code
USDA Forest Service
Number of cells per land-cover code
Internal
Land-cover class names
USDA Forest Service
Color
Color
Color
Color
Color
Color
The following land-cover classification scheme was used for the Washington, D.C. UTC assessment: Tree Canopy (1) - Living tree canopy Grass/Shrubs (2) - Low-lying vegetation that theoretically could be modified to accommodate additional tree canopy Water (4) - Water Impervious-Pavement (5) - Municipal sidewalks, minor driveways, and other impervious surfaces that theoretically could be modified to accommodate additional tree canopy Impervious-Buildings (6) - Buildings Impervious-Transportation (7) - Roads, large parking lots, major driveways, and railroads Bare Earth (8) - Exposed soil that theoretically could be modified to accommodate additional tree canopy Note that general UTC assessment protocols include a land-cover class for Agriculture (3), but this class was not reprersented in the Washington, D.C. land-cover map.
Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.
81 Carrigan Drive
Aiken Center Room 220