Deserts - English Online · Deserts 1 A desert is a hot area of land that gets very little...

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Deserts 1 A desert is a hot area of land that gets very little rainnot more than 200 mm a year. Temperatures during the daytime can get as high as 55° C. At night, de- serts cool down , sometimes even below 0° C. Deserts cover about 20% of the world’s land. The biggest is the Sahara desert, which is about the same size as Europe. Because deserts are very dry only certain kinds of plants and animals can live there. Locations of deserts Most deserts lie between 15° and 35° north and south of the equator. They were created by air that rises over the equator and comes down over the Tropic of Cancer and the Tropic of Capricorn . All over the world many deserts lie in these regions. 1. Land over the equator becomes very hot. The hot and wet air rises and it rains a lot in these areas. 2. The air cools down and moves northand southwards. It gets drier. 3. The cool air sinks to the ground . It dries out over the Tropic of Cancer in the north and the Tropic of Capricorn in the south. 4. Warm air near the surface moves back to the equator. These winds are called trade winds . Some deserts are formed in regions that are cut off from the ocean by high mountains. Winds carry wet air from the ocean to the land. When the air climbs WORDS certain =special cover =here: make up create = make cut off =separate little = not very much rise = go up surface =the top layer of an object trade wind = a tropical wind that blows to the equator from the northeast or the southeast Tropic of Cancer = a line around the world that lies 23½° north of the equator Tropic of Capricorn = a line around the world that lies 23½ ° south of the equator Equator Tropic of Cancer Tropic of Capricorn

Transcript of Deserts - English Online · Deserts 1 A desert is a hot area of land that gets very little...

Page 1: Deserts - English Online · Deserts 1 A desert is a hot area of land that gets very little rain—not more than 200 mm a year. Temperatures during the daytime can get as high as 55°

Deserts

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A desert is a hot area of land that gets very little rain—not more than 200 mm a

year. Temperatures during the daytime can get as high as 55° C. At night, de-

serts cool down , sometimes even below 0° C.

Deserts cover about 20% of the world’s land. The biggest is the Sahara desert,

which is about the same size as Europe.

Because deserts are very dry only certain kinds of plants and animals can live

there.

Locations of deserts

Most deserts lie between 15° and 35° north and south of the equator. They

were created by air that rises over the equator and comes down over the

Tropic of Cancer and the Tropic of Capricorn. All over the world many deserts

lie in these regions.

1. Land over the equator becomes very hot. The hot and wet air rises and it

rains a lot in these areas.

2. The air cools down and moves north– and southwards. It gets drier.

3. The cool air sinks to the ground . It dries out over the Tropic of Cancer in

the north and the Tropic of Capricorn in the south.

4. Warm air near the surface moves back to the equator. These winds are

called trade winds.

Some deserts are formed in regions that are cut off from the ocean by high

mountains. Winds carry wet air from the ocean to the land. When the air climbs

WORDS

certain =special

cover =here: make up

create = make

cut off =separate

little = not very much

rise = go up

surface =the top layer of an

object

trade wind = a tropical wind

that blows to the equator

from the northeast or the

southeast

Tropic of Cancer = a line

around the world that lies

23½° north of the equator

Tropic of Capricorn = a line

around the world that lies

23½ ° south of the equator

Equator

Tropic of

Cancer

Tropic of

Capricorn

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over high mountains it loses most of its moisture and when it falls down on

the other side it becomes very warm and dry. Deserts on the western coast of

North America were formed by such winds.

Many areas have become dry because they are too far away from the ocean. Air

loses its moisture by the time it reaches places that are thousands of kilome-

tres from the coast.

Deserts can also develop near the coast. Cold water moves from the Antarctic

northwards along the African and South American coast. The warm air in these

places cools down and mixes with the cool water. There is a lot of fog, but no

rain. That’s why the Atacama desert in Chile and the Namib desert in Africa

are among the driest deserts in the world.

Landscapes of the desert

Only about 10% of all deserts are made up of sand. Most of them are rocky

places that consist of gravel and larger stones. Desert landscapes are formed

mostly by the power of the wind and water.

Strong winds form rocks in strange ways. They also build up dunes made of

sand. Such dunes can be up to 200 m tall and they can travel large distances

every year.

After rainy times , small streams carry water. They cut their paths through the

desert and carry sediments with them .These streams often end in lakes

where the water evaporates and salt and minerals are left over.

Sometimes underground water comes to the surface. Such a place is called an

oasis . It is the only spot where people can live, plant crops and raise animals.

Climate

In summer, temperatures may reach up to 55°C during

the daytime , but at night they drop below 0° C.

Most deserts get very little rainfall— on average, not

more than 20 cm a year. There may be years without

any rainfall at all. Sometimes a lot of rain falls during

thunderstorms that last for a few hours.

When the desert dries up after heavy rainfall, salt and

other minerals are left behind on the ground. Salt lakes

are very common in these places. That is why some

desert areas have yellow, brown and red colours.

WORDS

among =together with

average =normal, usual

common = you can find some-

thing very often

consist of =to be made up of

cut =hack, chop

develop =build up

distance =the area from one

place to another

drop = go down

dune = a hill made of sand

evaporate = water changes

into gas

fog = cloudy air near the

ground. It is difficult to see

through it

gravel = small stones

heavy = very strong

landscape =an area or coun-

tryside of a special type

lose = it doesn’t have some-

thing any more

moisture = small parts of

water that exist in the air or

on the ground

northwards = to the north

oasis = a place with water

and trees in a desert

path = way

plant crops =to grow plants

like wheat or corn which

farmers use as food

raise = to look after animals

rocky =stony, full of rocks

sediment = small stones and

sand that rivers carry with

them

spot = place, area

stream = a very small river

surface =the top layer of an

object

thunderstorm = a storm with

thunder and lightning

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Living in the desert People who live in deserts must protect them-

selves from high temperatures during the day-

time and low temperatures at night and in the

winter.

Some people live in mud houses that are painted

white . They keep out the heat during the day-

time and protect people from cold evenings. No-

mads in Africa live in tents and move around all

year in search of areas with water. Many of

them wear long coats that protect them from

the sun and the wind.

Plant life Desert plants must change their way of life and get used to the heat and the

dryness.

Some flowers only live for a few days . The seeds may be in the desert ground

for years and when it rains they start to blossom.

Plants of the desert usually have small leaves that look like needles. Such

plants can live with very little water, which they store in the needles or stems.

Some plants have long roots that reach up to 80 metres below the surface.

Animals Many kinds of animals live in the desert: spiders, reptiles, birds and some mam-

mals.

Most animals stay in the shade during the daytime and look for food at night

when it gets cooler. They get water

from the food they eat or from the

water holes in the desert. Some ani-

mals sleep during the summer .

Camels are animals that are fit to

live in the desert. They can go on for

days without drinking water and need

only little to eat. They carry their

food in their humps. They also give

nomads wool and tents are made out

of their skin.

WORDS

blossom = to produce flowers

dryness =the situation of being

dry, without any water

fit =good enough; the right

ones

get used to =here: to be in a

new place so long that you can

live there without any problems

heat =high temperatures

hump = the high part of a

camel

in search of = to look for

mammal = an animal that

drinks milk from its mother’s

body when it is young

mud = wet earth that is soft

and sticky

needle =special kind of leaf

that is very sharp

nomad = a person who travels

from place to place to find

grass and water for animals

protect =defend , guard

reptile = an animal that

changes its body temperature,

like a snake

root = the part of a plant or a

tree that grows under the

ground and gets water there

seed = a small hard object of a

plant. A new plant can grow

from this

shade = out of the sunlight

stem = the long, thin part of a

plant

store = to put away until you

need it

surface =the top layer of an

object

tent =a shelter you put up

when you go camping; it is cov-

ered with cloth and you hang it

to the ground with ropes and

poles

water holes = a small place

where animals drink

wool = the soft thick hair of

some animals

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The Sahara

The Sahara is the biggest desert in the world . The landscape is made up of

mountain ranges, rocky plateaus and sandy plains called ergs. The Nile is the

only river that carries water all year long. It flows through the Sahara in Sudan

and Egypt.

The desert reaches from the Atlantic Ocean in the west to the Red Sea in the

east –over 3,500 km. The highest peaks are in the Tibesti mountains . They

reach a height of about 3,500 metres.

There are about 90 bigger oases in the Sahara, where water comes up from un-

derground rivers or wells. People here live in small villages and grow crops.

The Sahara also has important raw materials. Oil and gas lie under the Alge-

rian and Libyan desert. There are also other minerals ,like copper and iron

ore.

About 2 million people live in the desert. Most of them are Arabs or Berbers.

The Tuareg are a tribe that live in the mountainous areas of the central Sahara.

Most of them are nomads who raise sheep , goats or camels and travel around

all year.

In oases people can live the whole year. They grow dates, wheat and other

crops. But, they must also fight against sand storms and wandering dunes that

threaten to cover the oases with sand.

The Sahara was not always a desert. During the Ice Age , when many parts of

the world were covered with snow and ice, northern Africa had a much wetter

climate. The Sahara had many lakes and rivers and elephants and giraffes lived

in the grasslands and forests. At about 5000 BC the climate started to become

drier and the Sahara turned into a desert. Many people moved south .

Today the desert is growing because people destroy fertile land. They raise too

many animals that eat all the grass or they cut down trees that still exist.

WORDSl

BC = Before Christ

Berber = people who live in

Northern Africa

carry = to take with it

copper = a metal that shines

yellow and brown

cover =to spread over

crops =a plant like wheat or corn

that farmers grow for food

date = a sweet, sticky brown fruit

with a long hard stone inside

destroy =damage completely,

ruin

fertile =good, productive

height =how high something is

iron ore =rock from which you

can make iron

landscape =an area or country-

side of a special type

mountain range = a group of

mountains

nomad = a person who travels

from place to place to find grass

and water for animals

oasis = a place with water and

trees in a desert

peak = the sharp top of a moun-

tain

plains = a large area of flat land

plateau = a large area of flat

land that is higher than the land

around it

raise = to look after animals

raw material =things that exist in

nature and which we use every

day, like coal, oil, water

threaten =endanger, put at risk

tribe = a group of people who

have the same skin colour, lan-

guage and religion. They live in a

small area

wandering dunes = mountains of

sand that move from one place to

another

well = a deep hole in the ground

that has water in it

wheat =a plant that you make

white bread from

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Mohave

Desert

Great Basin

Atacama

Patagonian

Desert

Sahara

Namib Kalahari

Arabian

Desert Gobi

Australian

Desert

The most important deserts

of the world

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Overhead Transparency—

Desert Landscapes

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Overhead Transparency—

Plants in the Desert

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Answer the following questions !

What is the climate like in a desert ? Describe! _____________________________________________________

_____________________________________________________________________________________________

_____________________________________________________________________________________________

Hot and wet air rises over the ______________________ and sinks over __________________________ and

______________________________.

What are trade winds ? _________________________________________________________________________

Why are there deserts near the coast of South America and Africa ? ___________________________________

_____________________________________________________________________________________________

_____________________________________________________________________________________________

What material are most deserts made up of ? ______________________________________________________

_____________________________________________________________________________________________

What kind of life goes on in an oasis ? _____________________________________________________________

_____________________________________________________________________________________________

How do people who live in the desert protect themselves ? ___________________________________________

_____________________________________________________________________________________________

Where do desert plants keep their water ? _________________________________________________________

At which time of day are most desert animals active ? _______________________________________________

Why are camels fit to live in the desert ? __________________________________________________________

_____________________________________________________________________________________________

What are ergs ? _______________________________________________________________________________

Where do the Tuareg live and what do they do ? ____________________________________________________

_____________________________________________________________________________________________

What was the climate of the Sahara like during the Ice Age ? _________________________________________

_____________________________________________________________________________________________

Why is the Sahara desert still growing today ? ______________________________________________________

_____________________________________________________________________________________________

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The Sahara—Put the lines in the correct order

Sea in the east. About 2 million people live in the

sandstorms and wandering dunes. During the Ice

1 The Sahara desert is the biggest in the world. It

thousand years ago it started to dry out. Today

or other animals. Other people live in oases all

reaches from the Atlantic in the west to the Red

the desert grows because fertile land is destroyed.

desert. Most of them are nomads who raise sheep

Age the Sahara had a lot more rain, but a few

year long, but they must protect themselves from

The Sahara—Explain these words in English !

Tuareg _____________________________________________________________________________________

____________________________________________________________________________________________

date ________________________________________________________________________________________

____________________________________________________________________________________________

wandering dunes _____________________________________________________________________________

____________________________________________________________________________________________

well ________________________________________________________________________________________

____________________________________________________________________________________________

copper ______________________________________________________________________________________

____________________________________________________________________________________________

tribe _______________________________________________________________________________________

________________________________________________________________________________________________________

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Across

3. an animal that drinks milk from its mother's

body when it is young

5. line around the middle of the earth

8. when water change into gas

10. small stones and sand that rivers carry with

them

11. cloudy air near the ground. It is difficult to

see through it

12. a very small river

14. tropical wind that blows to the equator from

the northeast and southeast ( 2 words)

Down

1. an animal that is fit to live in the desert and

can go on for days without food and water

2. a person who travels from place to place to

find grass and water for animals

4. a group of people who have the same skin

colour and language and live in a small area

6. small parts of water that exist in the air or

on the ground

7. a place with water and trees in the desert

9. the part of a plan or a tree that grows under

the ground and gets water there

10. small stones and sand that rivers carry with

them

13. a hill made of sand

Crossword

1 2

3

4

5

6

7

8

9 10

11

12 13

14

Created with EclipseCrossword — www.eclipsecrossword.com

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U T O X P P J X Y D

B E R B E R B C U D

Y V C A M E L N M W

H S E D I M E N T J

R K G R O N F O G M

T I D Z A D F M S C

J R D M S A H A R A

W Y I B I T H D L E

D B E B S E N Z R L

U C O Z E U Q C I X

Look for 10 words about deserts

( ) and mark them.

Page 12: Deserts - English Online · Deserts 1 A desert is a hot area of land that gets very little rain—not more than 200 mm a year. Temperatures during the daytime can get as high as 55°

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Put the names of the deserts into

the blanks below !

1

2

3

4

5

6

7

8

9

10

1 ________________________________________

2 ________________________________________

3 ________________________________________

4 ________________________________________

5 ________________________________________

6 _______________________________________

7 _______________________________________

8 _______________________________________

9 _______________________________________

10 ______________________________________

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Explain how deserts are created

near the equator !

1 _____________________________________________________________________________________

______________________________________________________________________________________

2 _____________________________________________________________________________________

______________________________________________________________________________________

3 _____________________________________________________________________________________

______________________________________________________________________________________

4 _____________________________________________________________________________________

______________________________________________________________________________________

Equator

Tropic of Cancer Tropic of Capricorn

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Answer keys

Page 15: Deserts - English Online · Deserts 1 A desert is a hot area of land that gets very little rain—not more than 200 mm a year. Temperatures during the daytime can get as high as 55°

Deserts

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Crossword—Key

1 2

3

4

5

6

7

8

9 10

11

12 13

14

Created with EclipseCrossword — www.eclipsecrossword.com

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M

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V

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C

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Q

P

S

A

H

A

R

A

U

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M

D

N

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Word Search —Key

U T O X P P J X Y D

B E R B E R B C U D

Y V C A M E L N M W

H S E D I M E N T J

R K G R O N F O G M

T I D Z A D F M S C

J R D M S A H A R A

W Y I B I T H D L E

D B E B S E N Z R L

U C O Z E U Q C I X

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The Sahara—Put the lines in the correct order

3 Sea in the east. About 2 million people live in the

7 sandstorms and wandering dunes. During the Ice

1 The Sahara desert is the biggest in the world. It

9 thousand years ago it started to dry out. Today

5 or other animals. Other people live in oases all

2 reaches from the Atlantic in the west to the Red

10 the desert grows because fertile land is destroyed.

4 desert. Most of them are nomads who raise sheep

8 Age the Sahara had a lot more rain, but a few

6 year long, but they must protect themselves from