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Database of Geographic Information: Aspect 30_utm
Identifier:224_1
Publication date:2004
Author(s):
Alexander Buyantuyev
Abstract:
This dataset has been created to meet the needs of the research community of Arizona State University. Aspect can be thought of as the slope direction. It identifies the down-slope direction of the maximum rate of change in value (elevation) from each DEM cell to its neighbor cells. The values of the output grid are the compass direction of the aspect. The data is derived from the 30 meter Digital Elevation Model created for Central Arizona - Phoenix LTER (dem30_utm).
Keywords:
SLOPE, ASPECT, SONORAN DESERT, PHOENIX, urban, Elevation, informatics, caplter, Central Arizona Phoenix Longterm Ecological Research, metropolitan area, Arizona, Digital Elevation Model, slope direction, Database Remote Sensing GIS Applications, Project id 1, gis, remote sensing
Temporal Coverage:
1954-01-01 - 1984-01-01
Geographic Coverage:
Geographic Description:Central Arizona Phoenix
Bounding Coordinates:
Longitude:-113.291291 to -111.267307
Latitude:33.909966 to 32.888242
Contact:
Data Manager, Global Institute of Sustainability, Arizona State University,
Global Institute of Sustainability, Arizona State University, POB 875401,TEMPE
caplter.data@asu.edu
Methods used in producing this dataset:
Grid generation
The aspect grid was generated using the previsouly created 30 meter DEM (dem30_utm) in ArcInfo's grid function. Values in the grid were converted from floating point to integer format and value attribute table (.vat) was built. Although the original values are truncated, the accuray is not significantly affected. Aspect identifies the down-slope direction of the maximum rate of change in elevation from each cell to its neighbors. The values of the resulting grid are the compass direction of the aspect expressed in positive degrees from 0 to 360 and measured clockwise from the north. Cells in the input grid of zero slope (flat) are assigned an value of -1.
Entities:
Raster: aspect30_utm
download
Attributes:
Attribute:ObjectID
Description:Internal feature number.
Attribute:Value
Description:Slope aspect expressed in positive degrees from 0 to 360. Flat cells (slope=0) have values of -1.
Measurement Unit:degree
Attribute:Count
Description:Total number of grid cells of each particular value
Measurement Unit:number
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