Desert Survival Skills
| The
Basics
Wilderness Survival
Skills are the fundamental skills of survival
that will be needed for nearly every survival
scenario.
|
Desert Survival
[Reprinted
as permitted by U.S. Department of the Army from field
manual FM 21-76]
To survive and evade in arid or
desert areas, you must understand and prepare for the
environment you will face. You must determine your equipment
needs, the tactics you will use, and how the environment
will affect you and your tactics. Your survival will
depend upon your knowledge of the terrain, basic climatic
elements, your ability to cope with these elements,
and your will to survive.
Most arid areas have several types
of terrain. The five basic desert terrain types are--
- Mountainous (High Altitude).
- Rocky plateau.
- Sand dunes.
- Salt marshes.
- Broken, dissected terrain ("gebel"
or "wadi").
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 remains constant.
Mountain Deserts
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
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
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 high and 16 to 24 kilometers
long. Trafficability in such terrain will depend on
the windward or leeward slope of the dunes and the texture
of the sand. Other areas, however, may be flat for 3,000
meters and more. Plant life may vary from none to scrub
over 2 meters 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.
Salt Marshes
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 thick forms over the saltwater.
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 Shat-el-Arab waterway
along the Iran-Iraq border.
Broken Terrain
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 wide and 2 meters 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.
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.
In a desert area there are seven environmental
factors that you must consider--
- Low rainfall.
- Intense sunlight and heat.
- Wide temperature range.
- Sparse vegetation.
- High mineral content near ground
surface.
- Sandstorms.
- Mirages.
Low Rainfall
Low rainfall is the most obvious environmental
factor in an arid area. Some desert areas receive less
than 10 centimeters 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 "How much water do I have?"
and "Where are other water sources?"
Intense Sunlight and
Heat
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 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).
The temperature of desert sand and
rock averages 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).
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.
Radios and sensitive items of equipment
exposed to direct intense sunlight will malfunction.
Wide Temperature Range
Temperatures in arid areas may get
as high as 55 degrees C during the day and as low as
10 degrees C 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 helpful.
Sparse Vegetation
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.
If traveling in hostile territory,
follow the principles of desert camouflage--
- 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 outcropping. The temperature in shaded areas
will be 11 to 17 degrees C cooler than the air temperature.
- Cover objects that will reflect
the light from the sun.
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
away is really 3 kilometers away.
High Mineral Content
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; there-fore,
shelter is hard to find. Avoid these areas if possible.
Sandstorms
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 average
3.2 to 4.8 kilometers per hour (kph) and can reach 112
to 128 kph in early afternoon. Expect major sandstorms
and dust storms at least once a week.
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.
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.
Mirages
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 from the coast. They
make objects that are 1.5 kilometers or more away appear
to move.
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 "islands."
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 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 mirage.
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 flash-lights, and blackout lights at
great distances. Sound carries very far.
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 in a shelter, resting,
observing and memorizing the terrain, and selecting
your route.
The subject of man and water in the
desert has generated considerable interest and confusion
since the early days of World War II when the U. S.
Army was preparing to fight in North Africa. At one
time the U. S. Army thought it could condition men to
do with less water by progressively reducing their water
supplies during training. They called it water discipline.
It caused hundreds of heat casualties.
A key factor in desert survival is
understanding the relationship between physical activity,
air temperature, and water consumption. The body requires
a certain amount of water for a certain level of activity
at a certain temperature. For example, a person performing
hard work in the sun at 43 degrees C requires 19 liters
of water daily. Lack of the required amount of water
causes a rapid decline in an individual's ability to
make decisions and to perform tasks efficiently.
Your body's normal temperature is 36.9
degrees C (98.6 degrees F). Your body gets rid of excess
heat (cools off) by sweating. The warmer your body becomes--whether
caused by work, exercise, or air temperature--the more
you sweat. The more you sweat, the more moisture you
lose. Sweating is the principal cause of water loss.
If a person stops sweating during periods of high air
temperature and heavy work or exercise, he will quickly
develop heat stroke. This is an emergency that requires
immediate medical attention.
Figure 13-2 shows daily water requirements
for various levels of work. Understanding how the air
temperature and your physical activity affect your water
requirements allows you to take measures to get the
most from your water supply. These measures are--
- Find shade! Get out of the sun!
- Place something between you and
the hot ground.
- Limit your movements!
- Conserve your sweat. Wear your complete
uniform to include T-shirt. Roll the sleeves down,
cover your head, and protect your neck with a scarf
or similar item. These steps will protect your body
from hot-blowing winds and the direct rays of the
sun. Your clothing will absorb your sweat, keeping
it against your skin so that you gain its full cooling
effect. By staying in the shade quietly, fully clothed,
not talking, keeping your mouth closed, and breathing
through your nose, your water requirement for survival
drops dramatically.
- If water is scarce, do not eat.
Food requires water for digestion; therefore, eating
food will use water that you need for cooling.
Thirst is not a reliable guide for
your need for water. A person who uses thirst as
a guide will drink only two-thirds of his daily water
requirement. To prevent this "voluntary" dehydration,
use the following guide:
- At temperatures below 38 degrees
C, drink 0.5 liter of water every hour.
- At temperatures above 38 degrees
C, drink 1 liter of water every hour.
Drinking water at regular intervals
helps your body remain cool and decreases sweating.
Even when your water supply is low, sipping water constantly
will keep your body cooler and reduce water loss through
sweating. Conserve your fluids by reducing activity
during the heat of day. Do not ration your water!
If you try to ration water, you stand a good chance
of becoming a heat casualty.
Your chances of becoming a heat casualty
as a survivor are great, due to injury, stress, and
lack of critical items of equipment. Following are the
major types of heat casualties and their treatment when
little water and no medical help are available.
Heat Cramps
The loss of salt due to excessive sweating
causes heat cramps. Symptoms are moderate to severe
muscle cramps in legs, arms, or abdomen. These symptoms
may start as a mild muscular discomfort. You should
now stop all activity, get in the shade, and drink water.
If you fail to recognize the early symptoms and continue
your physical activity, you will have severe muscle
cramps and pain. Treat as for heat exhaustion, below.
Heat Exhaustion
A large loss of body water and salt
causes heat exhaustion. Symptoms are headache, mental
confusion, irritability, excessive sweating, weakness,
dizziness, cramps, and pale, moist, cold (clammy) skin.
Immediately get the patient under shade. Make him lie
on a stretcher or similar item about 45 centimeters
off the ground. Loosen his clothing. Sprinkle him with
water and fan him. Have him drink small amounts of water
every 3 minutes. Ensure he stays quiet and rests.
Heat Stroke
A severe heat injury caused by extreme
loss of water and salt and the body's inability to cool
itself. The patient may die if not cooled immediately.
Symptoms are the lack of sweat, hot and dry skin, headache,
dizziness, fast pulse, nausea and vomiting, and mental
confusion leading to unconsciousness. Immediately get
the person to shade. Lay him on a stretcher or similar
item about 45 centimeters off the ground. Loosen his
clothing. Pour water on him (it does not matter if the
water is polluted or brackish) and fan him. Massage
his arms, legs, and body. If he regains consciousness,
let him drink small amounts of water every 3 minutes.
In a desert survival and evasion situation,
it is unlikely that you will have a medic or medical
supplies with you to treat heat injuries. Therefore,
take extra care to avoid heat injuries. Rest during
the day. Work during the cool evenings and nights. Use
a buddy system to watch for heat injury, and observe
the following guidelines:
- Make sure you tell someone where
you are going and when you will return.
- Watch for signs of heat injury.
If someone complains of tiredness or wanders away
from the group, he may be a heat casualty.
- Drink water at least once an hour.
- Get in the shade when resting; do
not lie directly on the ground.
- Do not take off your shirt and work
during the day.
- Check the color of your urine. A
light color means you are drinking enough water, a
dark color means you need to drink more.
There are several hazards unique to
desert survival. These include insects, snakes, thorned
plants and cacti, contaminated water, sunburn, eye irritation,
and climatic stress.
Insects of almost every type abound
in the desert. Man, as a source of water and food, attracts
lice, mites, wasps, and flies. They are extremely unpleasant
and may carry diseases. Old buildings, ruins, and caves
are favorite habitats of spiders, scorpions, centipedes,
lice, and mites. These areas provide protection from
the elements and also attract other wild-life. Therefore,
take extra care when staying in these areas. Wear gloves
at all times in the desert. Do not place your hands
anywhere without first looking to see what is there.
Visually inspect an area before sitting or lying down.
When you get up, shake out and inspect your boots and
clothing. All desert areas have snakes. They inhabit
ruins, native villages, garbage dumps, caves, and natural
rock outcropping that offer shade. Never go barefoot
or walk through these areas without carefully inspecting
them for snakes. Pay attention to where you place your
feet and hands. Most snakebites result from stepping
on or handling snakes. Avoid them. Once you see a snake,
give it a wide berth.
[Reprinted as permitted
by U.S. Department of the Army from field manual FM
21-76]
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