208
Band
Scale
Date
Enhancement
technique
7
1:250,000
19.2.73
Destriped
7
1:250,000
21.12.75
High Pass Filter
4,5,7
(FCC)
1:250,000
19.2.73
Standard Mixed
Boxcar
4,5,7
(FCC)
1:250,000
27-3.73
Differential Edge
Enhancement
Table 2. Enhanced Landsat scenes.
Black and white aerial photographic cover at 1:60,000 scale was
obtained locally, comprising 68 stereo pairs.
Preliminary field reconnaissance surveys were organised. These were
used to gain a general overview of the regions physiography and resource
units so as to establish preliminary map legends.
The Landsat frames were visually examined (using a light table to
improve contrast) in a conventional manner and tentative interpretation
for each theme recorded on acetate film overlays. The standard FCC
formed the basis of these interpretations with other imagery
supplementing where necessary. Interpretation took 2-5 days depending
on the theme.
The aerial photographs were stereoscopically examined, the interpret
ations being drawn on acetate film fixed to one of each stereopair.
Interpretation took 15-20 man days for each theme.
A series of field investigations were conducted to visit photomorphic
units identified on the imagery. Those areas considered representative
of mapping units were selected to collect geomorphological, soil and
vegetation data. Interpretations were verified by visiting
photomorphically similar areas.
The identification legends used are as follows:
Geomorphological/Geological Units
These were identified and mapped with varying degrees of success.
A. Solid Geology
(a) Structure
(b) Bedrock/alluvium boundaries
(c) Lithology
B. Geomorphology
(a) Features of Geological origin
(i) Residual hill
(ii) Cliff
(iii) Steep bedrock slope
(iv) Pediment
(v) Basalt boulder covered slopes