Geoscience Reference
In-Depth Information
Study Area
Formation
Tundra
Forest
Woodland
Chaparral
Grassland
Desert Scrub
Riparian Forest/Woodland
Riparian Scrub
Water
Developed
N
0
50
100
200
Kilometers
Plate 14.1
(See color insert following page 114.) Preliminary AZ-GAP land-cover map to formation level
classification. See Appendix A for a complete list of all cover classes. The preliminary map contained
58,170 polygons describing 105 vegetation types (Appendix A).
set ranks for each cover type be assigned at each sampling point, this method would have been
impractical in the field. Instead, the fuzzy set ratings were predefined rather than assessed at each
sampling site. A matrix of the 105 cover classes (reference vs. map) assigned a fuzzy set rank to
each reference site by comparing its reference data assignment to the map assignment.
Using the fuzzy set rank for each reference site, the functions that described the thematic
accuracy of the classification were calculated (Gopal and Woodcock 1994). For this study, we
calculated the following functions:
Max (M)
=
number of sites with an absolutely right answer (accuracy rank of 5)
Right (R)
=
number of sites with a reasonable, good, or absolutely right answer (accuracy ranks of
3, 4, and 5)
