AERIAL PHOTOGRAPHY AND FORESTRY IN ASIA
matic film in combination with yellow filter.
The photographic quality was in general
good.
For military purposes large-scale photog-
raphy at a scale of 1:5,000 to 1:20,000 was
made along roads and railway tracts, in the
neighborhood of airfields, and in other par-
ticular areas important for local military ac-
tivities.
(Up to the present only 40,000 photographs
have been worked on for forestry purposes.)
Based upon this material Mr. Rollet was able
to make a vegetation map of South Vietnam
at a scale of 1:400,000 for a total area of
170,000 sq. km. Recently he also produced
a vegetation map of a part of Cambodia
situated east of the Mekong river. This map
was also based upon the same photographic
material and using the same identification
system, in total about 55,000 sq. km.
New vertical photography is currently be-
ing carried out in the area by an American
agency, size 9 by 9 inch, photo-scale 1 :40,000,
panchromatic film, in combination with a
yellow filter. Photographic quality is good;
prints are made in semi-matt. This photogra-
phy already covers the whole country of
Cambodia, the Southern part of Vietnam,
Laos and Thailand. Special selected areas,
important from a forestry point of view, are
photographed at 1:10,000. Photo-interpreta-
tion and type mapping will be carried out by
an American firm. This will result in a vegeta-
tion map at a scale of 1:40,000, while the
large-scale photography will be used for
timber volume estimations. This work is to
be started in 1960; it will possibly increase
our information about interpretation possi-
bilities of aerial photographs in tropical and
sub-tropical regions.
REFERENCES
1. Aung Myint, U. (1958): '"The Use of Aerial Sur-
vey in Managing Burma forests." The Burmese
Forester, 1958, pp. 181-188.
. Bedard, P. W. (1956): “Reconnaissance, Classi-
fication and Mapping of Philippine Forests.
Symposium on the Study of Tropical Vegeta-
tion," Unesco, Ceylon 1956, p. 8.
. Boon, D. A. (1956): Recent Development in
Photo-interpretation of Tropical Forests. Photo-
grammetria, 1956, pp. 382, 386.
4. De Rosayro, R. A. (1959): “The Application of
Aerial Photography to Stockmapping and In-
ventories on an Ecological Basis in Rainforest in
Ceylon.” The Empire Forestry Review, 38(2),
pp. 141-174.
. Hannibal, L. W. (1952): * Aerial Photo-inter-
pretation in Indonesia." Paper presented to the
2nd Asia-Pacific Forestry Commission of the
FAO, 1952, pp. 1-23.
6. Loetsch, F. (1957): A Forest Inventory in Thai-
land. Unasylva, 11(4), pp. 174-180.
7. Loetsch, F. (1958): “Der Einfluss des Brandro-
dungsbaus auf das Gefüge des Tropenwaldes
und die Wasserführung der Stróme, untersucht
am Beispiel Nord Thailands. Zeitschrift fiir
Erdkunde, Bnd XII, 182-205.
8. Miller, R. G. (1957): '"The Use of Aerial Photo-
graphs in Forestry in British Colonies." Paper
presented to the 7th British Comm. Forestry
Conference. Colonial Office, London, 1-7.
b
y
Cn
13