Database of Geographic Information: Topographic Map of Central Arizona

This dataset has been created to meet the needs of the research community of
Arizona State University. Apart from purely vizualization purposes (i.e. displaying
the data on various maps) it can potentially be used for spatial modeling. The data
consist of engineering-quality contours, also known as isolines, created from the
NED 10-meter Digital Elevation Model subset to the extent somewhat exceeding Cetral
Arizona - Phoenix LTER. Contours ( lines connecting points of equal height above sea
level) are drawn at 15 meter intervals with the base set at 145 m of elevation.
Contours are an exact interpretation of the grid surface model and may sometimes
appear blocky looking, may cross, appear to intersect, or form an unclosed branching
line. All these are valid engineering-quality interpretations of the elevation
surface that cartographers typically modify (smooth) for aesthetic purposes.