s, recogni-
water can
ow ground
ase of con-
to detailed
rces. Some
rtaining to
ways. To-
create local
s may :be
f a terrace
red by es-
r currents.
ictive sand
nd of pro-
dicates the
>mperature
d exposure
ates snow-
the ground
> the com-
ting trans-
1age, vege-
d. railroad
minals, air
ng country
Access may
port faci-
'ngineering
retation is
' here.
ng and are
me degree,
y of a site.
ated engi-
7 a general
ver, a reli-
engineering
features to
specialized
ous regions
ccuracy of
amount of
e complete
(649)
analysis than other terrain. À thick cover of forest or snow conceals the ground
surface from observation. On the other hand, these very factors may be means
for making special interpretations: an ecologic interpretation of the forest may
provide data on climate, slope, and soils; a light snow cover may bring out more
prominently irregularities in relief that would be unnoticed on photographs of
the bare ground. Needless to say, the quality, scale, coverage, and seasonal
spread of the photography has important bearing on the results.
References.
1. Elias, M. M., and Vosburgh, R. M., Terrain and Permafrost in the Galena
Area, Alaska, Permafrost Program, Progress Report No. 1, U.S. Geological
Survey, Washington, D.C., 1946.
2. Frost, Robert E., and Woods, K.B., Airphoto Patterns of Soils of the West-
ern United States as Applicable to Airport Engineering, Technical Devel-
opment Report No. 85, Civil Aeronautics Administration, Washington,
D.C., 1948.
3. Hittle, Jean E., Airphoto Interpretation of Engineering Sites and Materials,
Photogrammetric Engineering, vol. 15, No. 4, Dec. 1949, pp. 589-603.
4. Jenkins, D. S., Beleher, D. ].. Gregs. 1. E., and Woods, K. B., The Origin,
Distribution and Airphoto Identification of United States Soils, Technical
Development Report No. 52, Civil Aeronautics Administration, Wash-
ington, D.C., 1946.
5. Smith, Thomas R., and Black, Lloyd D., German Geography: War Work
and Present Status, Geographical Review, vol. 36, No. 5, July 1946, pp.
398-408.
