Safety / Survival / Army Field Manuals / AFM 3-05.70
13-1. Most arid areas have several types of terrain. The five basic desert
terrain types are—
13-2. Desert terrain makes movement difficult and demanding. Land navigation
will be extremely difficult as there may be very few landmarks. Cover and
concealment may be very limited; therefore, the threat of exposure to the enemy
13-3. Scattered ranges or areas of barren hills or mountains separated by
dry, flat basins characterize mountain deserts. High ground may rise gradually
or abruptly from flat areas to several thousand meters above sea level. Most of
the infrequent rainfall occurs on high ground and runs off rapidly in the form
of flash floods. These floodwaters erode deep gullies and ravines and deposit
sand and gravel around the edges of the basins. Water rapidly evaporates,
leaving the land as barren as before, although there may be short-lived
vegetation. If enough water enters the basin to compensate for the rate of
evaporation, shallow lakes may develop, such as the Great Salt Lake in Utah or
the Dead Sea. Most of these lakes have a high salt content.
ROCKY PLATEAU DESERTS
13-4. Rocky plateau deserts have relatively slight relief interspersed with
extensive flat areas with quantities of solid or broken rock at or near the
surface. There may be steep-walled, eroded valleys, known as wadis in the Middle
East and arroyos or canyons in the United States and Mexico. Although their flat
bottoms may be superficially attractive as assembly areas, the narrower valleys
can be extremely dangerous to men and material due to flash flooding after
rains. The Golan Heights is an example of a rocky plateau desert.
SANDY OR DUNE DESERTS
13-5. Sandy or dune deserts are extensive flat areas covered with sand or
gravel. "Flat" is a relative term, as some areas may contain sand
dunes that are over 300 meters (1,000 feet) high and 16 to 24 kilometers (10 to
15 miles) long. Trafficability in such terrain will depend on the windward or
leeward slope of the dunes and the texture of the sand. However, other areas may
be flat for 3,000 meters (10,000 feet) and more. Plant life may vary from none
to scrub over 2 meters (7 feet) high. Examples of this type of desert include
the edges of the Sahara, the empty quarter of the Arabian Desert, areas of
California and New Mexico, and the Kalahari in South Africa.
13-6. Salt marshes are flat, desolate areas, sometimes studded with clumps of
grass but devoid of other vegetation. They occur in arid areas where rainwater
has collected, evaporated, and left large deposits of alkali salts and water
with a high salt concentration. The water is so salty it is undrinkable. A crust
that may be 2.5 to 30 centimeters (1 to 12 inches) thick forms over the
13-7. In arid areas, there are salt marshes hundreds of kilometers square.
These areas usually support many insects, most of which bite. Avoid salt
marshes. This type of terrain is highly corrosive to boots, clothing, and skin.
A good example is the Shatt al Arab waterway along the Iran-Iraq border.
13-8. All arid areas contain broken or highly dissected terrain. Rainstorms
that erode soft sand and carve out canyons form this terrain. A wadi may range
from 3 meters (10 feet) wide and 2 meters (7 feet) deep to several hundred
meters wide and deep. The direction it takes varies as much as its width and
depth. It twists and turns and forms a mazelike pattern. A wadi will give you
good cover and concealment, but do not try to move through it because it is very
difficult terrain to negotiate.