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In spite of the fact that only a limited spectral 
a2one (400 — 1000 nm) is utilized by aerial photography, 
this method still remains the most universally used and 
efficient as regards the volume of information obtainable 
with it and the field of its application both in national 
economy, and in scientific investigations carried out in 
connection with exploring the national resources. 
Especially useful information is provided by aerial 
photography taken in connection with making maps of every 
kind = topographical, geological, of landscape, soils, 
geobotanical, of forests, etc. 
Aerial photographs are also used for taking stock 
of wooded lands, organization of land exploitation, land 
reclamation, projecting of railways and roads, of elec- 
trical and pipe-lines. 
Aerial photographs are used in the USSR : 
- in geographical investigations of evely kind, landscape 
studies, realization of measures intended for nature 
protection, 
~ in geological investigations on land and in shallow sea 
areas, 
- in soil and vegetation studies, 
- in the study of hydrological conditions on land, hydro- 
logical processes on shore and in river-beds and 
channels, 
= in the study of sea currents and sea roughness, 
- in glaciological studies, 
= in archeological investigations, 
= in the study of food-and game resources, stock-taking 
of different species of animals, fish, their protec- 
tion, etc. 
Utilization of aerial photographs in all the mention- 
ed branchs allows to decrease the volume of field work 
and reduce cost, 
The method of extracting all needed information out 
of aerial photographs (i.e. photo-interpretation has 
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