:SSION
LAND
uplands. See Legend for areal distribution.
(3) The detail of mapping of the floodplains in the ground truth map could not be matched
by the digite! classification. On the other hand, the uplands were not mapped beyond the litho-
logical difterentiation on the GI map simply because of time and cost, whereas the computer
went into such detailed differentiation of refiectance classes of these large terrain units that
would have taken months ot photo interpretation and field work to accomplish if done by con-
ventional means (api * field work). Fig. 3.
Fig. 3. Ground Truth map by aerial photo interpretation and field work. Note
the detailed mapping in floodplains and sand islands and the demarcation of
the major landforms and geological units but little or no subdivision of the