Description of Parent Data Set: It is in a vector digital data structure, digitized from a map of New Mexico whose scale is unknown. The source software used was ARC/INFO 7.0.3 and the conversion software ARC/INFO 7.0.3.
Intended use of data: These data are to be used as base reference to the 1:250,000 scale USGS land use / land cover maps. The data are intended for use as a general reference to the extent and boundaries of these maps.
Related spatial and tabular data sets: Rio Puerco Watershed Basin Boundary (wshed)
The original data set was incomplete within the USGS Chaco Mesa 1:100,000 scale map (between 107 degrees West longitude and 108 degrees West longitude, and 36 degrees North latitude and 36 degrees, 30 minutes North latitude. All polygon and attribute information was missing. This information was available in paper map form in USGS Open File Report 79-1549-1.
In order to add the Chaco Mesa data to the original land use / land cover file, several steps were taken. First, the paper map from OFR 79-1549 was scanned at 300 dots per inch, using an Anatech Large Format Scanner, creating a .tif file. This .tif file was opened in Adobe Photoshop version 5.0, where unwanted lines and unneccessary objects (such as numbers, legends, scale bars, and fold lines) were removed. The "cleaned" .tif file was then registered in Arc/Info version 7.1.1 to UTM Zone 13 coordinates.
Next, a grid file was created by using the IMAGEGRID command. In GRID, the SETNULL command was used to eliminate all cell values greater than 245, and the line work was set equal to 1. The GRIDLINE command was used to produce the final line coverage.
In ARCEDIT, the polygons were closed, dangles and unneccessary lines were deleted, and a new coverage was produced. Attributes (land use codes) were then assigned to the polygons, and topology was built.
Finally, the new coverage was combined with the original coverage using the APPEND command. The coverage was CLEANed (to correct errors, assemble arcs and polygons, and create feature attribute information), and then the polygons were DISSOLVEd (to merge adjacent polygons with the same attributes). Again, dangles and unneccessary lines were corrected, and topology was built. Polygon attributes were verified with the source maps.
The 'code' attribute contains Anderson Level I and Level II land use / land cover classification codes.
Anderson Level I codes:
1-Urban or built-up land 2-Agricultural land 3-Rangeland 4-Forest land 5-Water 6-Wetland 7-Barren land 8-Tundra 9-Perennial snow or ice
Anderson Level II codes:
11-Residential 12-Commercial and services 13-Industrial 14-Transportation, communication, utilities 15-Industrial and commercial complexes 16-Mixed urban or built-up land 17-Other urban or built-up land
21-Cropland and pasture 22-Orchards, groves, vineyards, nurseries, and horticultural areas 23-Confined feeding operations 24-Other agricultural land
31-Herbaceous rangeland 32-Shrub and brush rangeland 33-Mixed rangeland
41-Deciduous forest 42-Evergreen forest 43-Mixed forest
51-Streams and canals 52-Lakes 53-Reservoirs 54-Bays and estuaries
61-Forested wetland 62-Nonforested wetland
71-Dry salt flats 72-Beaches 73-Sandy areas, not beaches 74-Bare exposed rock 75-Strip mines, quarries, gravel pits 76-Transitional areas
81-Shrub and brush tundra 82-Herbaceous tundra 83-Bare ground 84-Wet tundra 85-Mixed tundra
91-Perennial snowfields 92-Glaciers
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