Exploring Our World

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Transcript Exploring Our World

Chapter 1
Physical Geography of Africa
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Physical Geography of Africa
Chapter Introduction
Section 1: Physical
Features
Section 2: Climate Regions
Summary
Physical Geography of Africa
Regions The physical
environment of Africa is diverse.
It ranges from deserts to rain
forests, from mountains to
rolling grasslands to jagged
cliffs. Some areas of Africa’s
interior are very difficult to
reach. How do physical
features influence a region’s
climate?
Physical Geography of Africa
Section 1:
Physical Features
Physical processes shape
Earth’s surface. Over
thousands of years, the
movement of the Earth’s tectonic
plates has shaped the landforms
of Africa. The region’s landscape
includes huge deserts, large
plateaus, rocky cliffs, and great,
steep valleys.
Physical Geography of Africa
Section 2:
Climate Regions
Geographers organize the
Earth into regions that share
common characteristics.
Africa has four main climate
regions, each of which covers a
large area. Similar climate zones
appear north and south of the
Equator in the region. Climates
range from damp rain forests to
vast grasslands to hot deserts.
Physical processes shape Earth’s
surface.
Do you believe reliable water and
sanitation systems should be
provided by the government or
private companies?
A. Government
B. Private companies
C. Neither
D. Not sure
Without warning, in the mid-1980s, huge amounts of
poisonous carbon dioxide gas escaped from Lakes
Nyos and Mounoun in Cameroon, killing more than
2,000 people. The gas originated in volcanic magma
underground and eventually seeped into the lakes,
where it exploded. Special pipes now control the
release of the gas in harmless amounts.
Landforms of Africa
Africa consists mainly of vast
deserts and plateaus with
some mountains and
lowlands.
Landforms of Africa (cont.)
• Almost all of Africa lies on a series of
plateaus that rise like steps across the
continent from west to east and from the
coasts into the interior.
• In eastern and southern Africa, the edges
of plateaus are often marked by steep,
jagged cliffs called escarpments.
• Africa also has some lowland areas. The
Congo Basin in central Africa is the largest
lowland area in Africa’s interior.
Africa
Landforms of Africa (cont.)
• Sahara, the world’s largest hot desert,
covers much of North Africa.
• South of the Sahara lies a region known
as the Sahel.
• The Kalahari desert in Botswana is
covered by vast stretches of sand.
• The Namib, along the coast of Namibia, is
made up of rocks and dunes.
Africa
Landforms of Africa (cont.)
• The Ahaggar Mountains, Tibesti Mountains,
and the Atlas Mountains are in North Africa.
• In the east are the Ethiopian Highlands
and volcanic mountain peaks, such as
Kilimanjaro and Mount Kenya.
• Kilimanjaro in Tanzania is the highest peak
in the region at 19,341 feet (5,895 m).
• The Drakensberg Range is in southern
Africa.
Africa
Landforms of Africa (cont.)
• The Great Rift Valley in eastern Africa cuts
through the flatness of large plateau areas.
• A rift valley is a large, visible break in the
Earth’s surface formed by shifting tectonic
plates.
• Some areas of the Great Rift Valley have
rich volcanic soil that supports farming.
Africa
Which mountain range is found in the North
Africa region?
A. Zagros
B. Hindu Kush
C. Tian Shan
D. Atlas
Waterways of the Region
Waterways provide
transportation, freshwater,
and electricity for Africans.
Waterways of the Region (cont.)
• Most of the continent’s large lakes lie in or
near East Africa’s Great Rift Valley.
• Lake Tanganyika is the longest fresh water
lake in the world.
• Lake Victoria lies in a low basin and is
Africa’s largest lake.
• Lake Chad in West Africa changes
dramatically in size between the rainy
season and the dry season.
Waterways of the Region (cont.)
• Africa has four large river systems—the
Nile, the Congo, the Niger, and the
Zambezi.
• All of these rivers begin in the interior
plateaus and make their way to the sea.
• In some places these rivers and their
many branches are useful for freshwater
and transportation, but geographical
barriers limit their use in other areas.
Waterways of the Region (cont.)
• The Suez Canal is a human-made
waterway on Egypt’s eastern edge.
• It is used by ships to pass from the
Mediterranean Sea to the Red Sea.
• It is one of the most important and most
used shipping lanes in the world.
Waterways of the Region (cont.)
• Clean water is scarce throughout much of
Africa.
• Dams have been built to control flooding in
the parts of Africa where rivers and lakes
provide plentiful water.
• The dams have resulted in both benefits
and environmental damages.
What do the region’s four main rivers
have in common?
A. They all originate in Zambia.
B. They all flow into the Atlantic Ocean.
C. They all begin in the interior plateaus
and make their way to the sea.
Resources
Africa holds both a great
variety and large quantities of
mineral and other resources.
Resources (cont.)
• Africa is rich in energy resources.
• Oil has replaced agricultural products as
the principal export in many African
countries.
• Other important resources include: natural
gas, coal, hydroelectric power, iron ore,
chromium, uranium, and copper.
Resources (cont.)
• Africa has large deposits of precious
materials such as: gold ore, platinum,
chromium, and manganese.
• A large number of gemstones are mined in
Africa, including diamonds, rubies,
emeralds, and sapphires.
• South Africa is a major diamond producer.
What important resource do the fastflowing rivers provide?
A. Hydroelectric power
B. Nuclear power
C. Petroleum deposits
D. Gold
Geographers organize the Earth into
regions that share common
characteristics.
What kind of climate would you prefer
to live in?
A. Mediterranean
B. Tropical
C. Highland
D. Desert
Uganda, second in the world in banana production, is
looking into making paper with banana fibers instead of
with traditional wood pulp from trees. The process uses
the stems and leaves from the banana plants that are
otherwise thrown away as waste. If it works, banana
farmers will be able to sell both the fruit and the waste,
boosting the economy, and the environment will have
another protection against deforestation.
Factors Affecting Climate
Most of Africa has warm or hot
climates. Rainfall, however,
varies greatly throughout the
region.
Factors Affecting Climate (cont.)
• Africa lies mainly in the Tropics, resulting
in direct rays of the sun year-round and
generally high temperatures.
• Places with high elevation, though, often
are cooler than lowland areas at the same
latitude.
• Africa has wet, dry, and temperate climate
zones.
Africa: Climate Zones
Factors Affecting Climate (cont.)
• Some parts of Africa have long droughts,
or periods of time when there is no rain at
all.
• Droughts can cause crop failures and
widespread starvation.
Africa: Climate Zones
How much rain falls in the Sahara in
Northern Africa?
A. More than 80 inches
(203 cm) per year
B. None
C. About 3 inches
(7 cm) or less per year
Tropical and Dry Climates
Most of Africa is covered by
tropical or dry climate zones.
Tropical and Dry Climates (cont.)
• A tropical wet climate is found along the
Equator in Central Africa and West Africa.
• Hot temperatures and plentiful rainfall in
this zone support the growth of rain
forests, or dense stands of trees and
other plants that receive high amounts of
precipitation each year.
Tropical and Dry Climates (cont.)
• Rain forests support an enormous variety
of plant and animal life.
• But because many tropical African
countries rely on the sale of products from
the rain forests, such as wood, for income,
they take part in the widespread clearing
of forestland, called deforestation.
Tropical and Dry Climates (cont.)
• To preserve rain forests, and boost their
economies, some African countries are
encouraging ecotourism. Ecotourism is
touring a place without causing harm to
the environment.
Tropical and Dry Climates (cont.)
• Farther from the Equator, rain forests give
way to great stretches of grasslands with
scattered woods, called tropical
savannas, where temperatures remain hot
all year, but rainfall amounts are much
lower than in rain forest areas.
Tropical and Dry Climates (cont.)
• Continuing farther from the Equator,
rainfall becomes more scarce, and
savannas merge into drier steppes
that have only about 8 to 15 inches
(20 to 38 cm) of rain over the course of
a few months each year.
• Steppe areas are threatened by
desertification, the process that turns fertile
land into land that is too dry to support life.
Tropical and Dry Climates (cont.)
• The Sahara Desert in the north has high
temperatures and little rain.
• When rain falls in the Kalahari Desert in
Southern Africa, it is immediately absorbed
by the sand, leaving the surface dry.
• The Namib Desert, along the southwestern
coast, is made up of rocks and dunes.
What factors are threatening the savanna
plants and animals of Africa?
A. Hunting
B. Human settlement
C. Pollution
D. Both A and B
Moderate Climate Regions
Small areas of Africa have
moderate climate regions.
Moderate Climate Regions (cont.)
• Moderate climates, with comfortable
temperatures and enough rainfall for
farming, are found in coastal North Africa,
Southern Africa, and the highlands of East
Africa.
• Southeastern Africa has a humid
subtropical climate of hot, wet summers
and mild, wet winters.
• The farther south you go in this region, the
farther you are from the Equator, resulting
in cooler temperatures.
Moderate Climate Regions (cont.)
• Coastal North Africa and southwestern
Africa has a Mediterranean climate in
which winters are mild and wet, but the
summers are warm and dry.
• Highland climates are found in areas of
higher elevation in East Africa.
In Southwestern Africa, in which season are
Christmas, Hanukkah, and Kwanza?
A. Near the beginning
of summer
B. Near the beginning
of winter
C. Near the beginning
of spring
D. Near the beginning of fall
Landforms
• Most of Africa lies on a series of plateaus.
• Africa’s landforms include deserts,
plateaus, and volcanic peaks.
• Narrow plains hug Africa’s coastlines. In
some places, the plains spread deep into
inland areas.
Waterways
• Most lakes lie in the Great Rift Valley.
Lakes are a source of freshwater and fish.
• The major rivers of Africa are the Nile, the
Congo, the Niger, and the Zambezi.
A Tropical Region
• Tropical rain forests have hot temperatures
and plentiful rains throughout the year.
• The amount of rainfall varies in the
savannas. A variety of animals lives on
these grasslands.
• Several countries have created national
parks to protect forests and grasslands.
Deserts and Steppes
• Deserts dominate the landscape in large
areas of Africa.
• The main deserts include the Sahara, the
Kalahari, and the Namib.
• Partly dry grasslands near deserts are
threatened by desertification.
Moderate Climates
• Parts of southeastern and southwestern
Africa lie outside the Tropics. They have
moderate climates.
• Highland climates are found in
mountainous areas of East Africa.
• Temperatures in the highlands are cooler
than in surrounding areas because of
higher altitude.
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