Safety / Survival / Army Field Manuals / AFM 3-05.70
13-9. Surviving and evading the enemy in an arid area depends on what you
know and how prepared you are for the environmental conditions you will face.
Determine what equipment you will need, the tactics you will use, and the
environment's impact on them and you.
13-10. In a desert area there are seven environmental factors that you must
13-11. Low rainfall is the most obvious environmental factor in an arid area.
Some desert areas receive less than 10 centimeters (4 inches) of rain annually,
and this rain comes in brief torrents that quickly run off the ground surface.
You cannot survive long without water in high desert temperatures. In a desert
survival situation, you must first consider the amount of water you have and
other water sources.
INTENSE SUNLIGHT AND HEAT
13-12. Intense sunlight and heat are present in all arid areas. Air
temperature can rise as high as 60 degrees C (140 degrees F) during the day.
Heat gain results from direct sunlight, hot blowing sand-laden winds, reflective
heat (the sun's rays bouncing off the sand), and conductive heat from direct
contact with the desert sand and rock (Figure 13-1).
Figure 13-1. Types of Heat Gain
13-13. The temperature of desert sand and rock typically range from 16 to 22
degrees C (30 to 40 degrees F) more than that of the air. For instance, when the
air temperature is 43 degrees C (110 degrees F), the sand temperature may be 60
degrees C (140 degrees F).
13-14. Intense sunlight and heat increase the body's need for water. To
conserve your body fluids and energy, you will need a shelter to reduce your
exposure to the heat of the day. Travel at night to lessen your use of water.
13-15. Radios and sensitive items of equipment exposed to direct intense
sunlight will malfunction.
WIDE TEMPERATURE RANGE
13-16. Temperatures in arid areas may get as high as 55 degrees C (130
degrees F) during the day and as low as 10 degrees C (50 degrees F) during the
night. The drop in temperature at night occurs rapidly and will chill a person
who lacks warm clothing and is unable to move about. The cool evenings and
nights are the best times to work or travel. If your plan is to rest at night,
you will find a wool sweater, long underwear, and a wool stocking cap extremely
13-17. Vegetation is sparse in arid areas. You will therefore have trouble
finding shelter and camouflaging your movements. During daylight hours, large
areas of terrain are visible and easily controlled by a small opposing force.
13-18. If traveling in hostile territory, follow the principles of desert
Hide or seek shelter in dry washes (wadis) with thicker growths of
vegetation and cover from oblique observation.
Use the shadows cast from brush, rocks, or outcroppings. The temperature
in shaded areas will be 11 to 17 degrees C (52 to 63 degrees F) cooler than
the air temperature.
Cover objects that will reflect the light from the sun.
13-19. Before moving, survey the area for sites that provide cover and
concealment. You will have trouble estimating distance. The emptiness of desert
terrain causes most people to underestimate distance by a factor of three: What
appears to be 1 kilometer (1/2 mile) away is really 3 kilometers (1 3/4 miles)
HIGH MINERAL CONTENT
13-20. All arid regions have areas where the surface soil has a high mineral
content (borax, salt, alkali, and lime). Material in contact with this soil
wears out quickly, and water in these areas is extremely hard and undrinkable.
Wetting your uniform in such water to cool off may cause a skin rash. The Great
Salt Lake area in Utah is an example of this type of mineral-laden water and
soil. There is little or no plant life; therefore, shelter is hard to find.
Avoid these areas if possible.
13-21. Sandstorms (sand-laden winds) occur frequently in most deserts. The Seistan
desert wind in Iran and Afghanistan blows constantly for up to 120 days. Within
Saudi Arabia, winds typically range from 3.2 to 4.8 kilometers per hour (kph) (2
to 3 miles per hour [mph]) and can reach 112 to 128 kph (67 to 77 mph) in early
afternoon. Expect major sandstorms and dust storms at least once a week.
13-22. The greatest danger is getting lost in a swirling wall of sand. Wear
goggles and cover your mouth and nose with cloth. If natural shelter is
unavailable, mark your direction of travel, lie down, and sit out the storm.
13-23. Dust and wind-blown sand interfere with radio transmissions.
Therefore, be ready to use other means for signaling, such as pyrotechnics,
signal mirrors, or marker panels, if available.
13-24. Mirages are optical phenomena caused by the refraction of light
through heated air rising from a sandy or stony surface. They occur in the
interior of the desert about 10 kilometers (6 miles) from the coast. They make
objects that are 1.5 kilometers (1 mile) or more away appear to move.
13-25. This mirage effect makes it difficult for you to identify an object
from a distance. It also blurs distant range contours so much that you feel
surrounded by a sheet of water from which elevations stand out as
13-26. The mirage effect makes it hard for a person to identify targets,
estimate range, and see objects clearly. However, if you can get to high ground
(3 meters [10 feet] or more above the desert floor), you can get above the
superheated air close to the ground and overcome the mirage effect. Mirages make
land navigation difficult because they obscure natural features. You can survey
the area at dawn, dusk, or by moonlight when there is little likelihood of
13-27. Light levels in desert areas are more intense than in other geographic
areas. Moonlit nights are usually crystal clear, winds die down, haze and glare
disappear, and visibility is excellent. You can see lights, red flashlights, and
blackout lights at great distances. Sound carries very far.
13-28. Conversely, during nights with little moonlight, visibility is
extremely poor. Traveling is extremely hazardous. You must avoid getting lost,
falling into ravines, or stumbling into enemy positions. Movement during such a
night is practical only if you have a compass and have spent the day resting,
observing, and memorizing the terrain, and selecting your route.