difference between the estimates of the fir and kail areas
by ground survey and photo-interpretation (scale 1:40.000)
is very small (probably due to simple structure and compo-
sition of vegetation) whereas in the case of mixed forests
of Bastar the differences are significant.
(iv) Difference in the mean height of 294 plots on the ground
and the photo is negligible. However, the high magnitude
of the standard deviation of the difference may be due to
random differences in location of trees on the ground and
photo plots and also due to the differences among the
interpreters.
(v) Lastly it can be said that black and white panchromatic
aerial photographs can be effectively used in preparation
of forest vegetation type and landuse maps, in estimation
of area under different vegetation types, reducing the
amount of ground sampling by forest stratification prior
to undertake field work and to improve the total volume
estimates.
2. Landsat imagery in forest mapping and surveys:
In order to keep pace with ever increasing requirement of raw
materials for agro forest industries, a comprehensive, rapid,
real time and repetitive assessment of the forest resources
potential becomes inevitable. The use of frequent aerial photo-
graphy for the assessment of large tracts of land is prohibitively
costly. The recent remote sensing techniques, particularly multi-
band sensing methods which are still in early stages of research
with reference to forestry is expected to provide some solution
to the problem.
2.1. Material and Method of Study:
With a view to find out the usefulness of Landsat imagery in
forestry, the Landsat imagery (E-1219-0437-502 exposed on 26.2.73
and E-1219-0437-502 exposed on 27.2.73) in bands 4, 5, 6 and 7
on 1:1000.000 and in band 5 on 1:250.000 scale with reference
to Mahadevpur Reserved forests of Karimnagar East Forest Division
and to the Gudem reserved forests of Kagharznagar Forest Division
respectively of Andhra Pradesh were studied and interpreted
visually. The false colour print of the imagery pertaining to
the second area of study on 1:250.000 scale was also studied.
All the imagery were of good quality and free from cloud shadows.
The general tone of band seven imagery was the darkest whereas
that o band six was the lightest. Band five imagery was the next
darkest. The tonal contrast among different vegetation types
was observed and found to be best in band five imagery and poor
in band six and seven imagery. Band four showed better tonal
contrast than bands six and seven. And the false colour print
imagery pertaining to Gudem reserved forests showed even better
tonal contrast than band five imagery. As false colour and band
five imagery offered best interpretation possibilities, enlarge-
ments of band five and that of false colour were got made on
1:250.000 for further study.