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DESERT SURVIVAL
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.
TERRAIN
Most arid areas have several types of terrain. The five basic
desert
terrain types are—
Mountainous (High Altitude).
Rocky plateau.
Sand dunes.
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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
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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.
ENVIRONMENTAL FACTORS
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.
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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
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,
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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.
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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; therefore,
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.
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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 flashlights,
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.
NEED FOR WATER
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
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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
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
hotblowing
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.
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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.
HEAT CASUALTIES
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
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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.
PRECAUTIONS
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.
DESERT HAZARDS
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 wildlife.
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.
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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.
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