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Chapter Introduction Section 1: Physical Features Section 2: Climate Regions Visual Summary Regions The physical environment of Africa south of the Sahara 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? 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 south of the Sahara. The region’s landscape includes large plateaus, rocky cliffs, and great, steep valleys. Section 2: Climate Regions Geographers organize the Earth into regions that share common characteristics. Africa south of the Sahara 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. Content Vocabulary • escarpment • gorge • rift valley • industrial diamond Academic Vocabulary • series • principal A large camel can drink 25 gallons (95 l) of water in 10 minutes! It then stores the water in its bloodstream. Camels sweat very little, so the water they drink can last for weeks. Unlike a camel, a person in a desert can lose about two gallons of water a day by sweating! Humans must replace water frequently. Water is more plentiful in some regions of Africa south of the Sahara than in others. Read on to learn more about the physical features of this region. 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 0% A A. B. C. 0% D. B A B C 0% D C 0% D 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 South of the Sahara Africa south of the Sahara consists mainly of vast plateaus with few mountains and lowlands. Landforms of Africa South of the Sahara (cont.) • Almost all of Africa south of the Sahara lies on a series of plateaus. – The plateaus are formed from the solid rock that lies under most of the African continent and rise like steps across the continent from west to east and from the coasts into the interior. Landforms of Africa South of the Sahara (cont.) – Many rise from 1,000 to 2,000 feet (305 to 610 m) in western Africa to 7,000 feet (2,134 m) or more in the east, giving the area the highest overall elevation of any world region—more than 1,000 feet (305 m) above sea level. Landforms of Africa South of the Sahara (cont.) • In eastern and southern Africa, the edges of plateaus are often marked by steep, jagged cliffs called escarpments. – Rivers that flow across plateaus drop suddenly at escarpments to become rushing rapids or tumbling waterfalls. – Escarpments create barriers to trade by blocking ships from sailing between the interior and the sea. Landforms of Africa South of the Sahara (cont.) • Lowland areas include a narrow band of plains that border the region’s Atlantic and Indian Ocean coastlines and low, sunken areas called basins. – Basins formed when tectonic activity lifted up the land surrounding them. – The Congo Basin is the largest lowland area in Africa’s interior. Landforms of Africa South of the Sahara (cont.) • In the east are the Ethiopian Highlands as well as volcanic mountain peaks, such as Kilimanjaro and Mount Kenya. – Kilimanjaro in Tanzania is the highest peak in the region, rising to a height of 19,341 feet (5,895 m). – Even though the mountain sits almost on the Equator, snow covers the summit year-round. Landforms of Africa South of the Sahara (cont.) • The Great Rift Valley cuts about 4,000 miles (6,437 km) through the flat plateau of eastern Africa, stretching from Southwest Asia to Southern Africa. – A rift valley is a large break in the Earth’s surface formed by shifting tectonic plates, volcanic eruptions, and earthquakes. Landforms of Africa South of the Sahara (cont.) – In some places, the walls rise 9,000 feet (2,743 m) from the valley floor. – Features include jagged mountains, deep lakes, and rich volcanic soil that supports farming. Africa South of the Sahara What do people call the eastern side of the Drakensburg Range? A. Shining Mountain B. Barrier of Pointed Spears B A A. A B. B 0% 0% C. C 0% C C. Great Rift Valley Waterways of the Region Waterways provide transportation, freshwater, and electricity for Africans living south of the Sahara. Waterways of the Region (cont.) • Most of the large lakes in Africa south of the Sahara lie in or near East Africa’s Great Rift Valley. • Lake Tanganyika is 420 miles (676 km) in length, making it the longest freshwater lake in the world. Waterways of the Region (cont.) • Lake Victoria lies in a low basin and is Africa’s largest lake and the world’s second-largest freshwater lake, after Lake Superior in North America. • Lakes in the Great Rift Valley provide freshwater and fish to people who live near them. Waterways of the Region (cont.) • Some Great Rift Valley lakes also serve as the sources of rivers. • Lake Victoria is the source of the White Nile, and Lake Tana is the source of the Blue Nile. • These two rivers meet farther north in Sudan to form the Nile River, the world’s longest river. Waterways of the Region (cont.) • Lake Chad, which lies in West Africa, changes dramatically in size from about 10,000 square miles (25,900 sq. km) in the rainy season to about 3,800 square miles (9,842 sq. km) in the dry season. Waterways of the Region (cont.) • The same tectonic activity that produced the region’s rugged landscape also affected the region’s rivers. • Escarpments create waterfalls and rapids that make transportation on some rivers difficult. Waterways of the Region (cont.) • The Zambezi River in southern Africa plunges over a cliff, creating Victoria Falls, a series of waterfalls that drop as much as 420 feet (128 m). Waterways of the Region (cont.) • Rivers that begin in African highland areas shape the land. • Many, like the Congo, flow through plateaus and carve deep gorges, steepsided valleys formed when rivers cut through the land. • Other rivers are interrupted by inland lakes and marshes that can hinder travel. What do the region’s four main rivers have in common? A. They all originate in Zambia. B A C. They all begin in the interior plateaus and make their way to the sea. A. A B. B C 0%C. 0% 0% C B. They all flow into the Atlantic Ocean. Mineral Resources Africa south of the Sahara holds both a great variety and large quantities of mineral resources. Mineral Resources (cont.) • Plentiful petroleum deposits are found along the Atlantic coast from Nigeria to Angola and in landlocked Chad and Sudan. • Oil has replaced agricultural products as the principal export in many countries. Mineral Resources (cont.) • Natural gas is found in Central African countries along the Atlantic coast; Nigeria, the Democratic Republic of the Congo, and the Republic of South Africa have coal deposits. Mineral Resources (cont.) • Large reserves of iron ore exist throughout Africa south of the Sahara, including vast amounts in Zimbabwe. • Chromium, needed to make steel, is mined in Zimbabwe, South Africa, and several countries of both West and East Africa. • Deposits of uranium—used to produce nuclear power—and copper are also found in the region. Mineral Resources (cont.) • South Africa is believed to have half of the world’s gold and is also rich in platinum. • Many gemstones are mined in the region, including diamonds, rubies, emeralds, and sapphires. • Industrial diamonds mined here are used to make drills, saws, and grinding tools. What important resource does the fast-flowing rivers provide? A. Hydroelectric power B. Nuclear power C. Petroleum deposits D. Gold 0% A A. B. C. 0% D. B A B C 0% D C 0% D Geographers organize the Earth into regions that share common characteristics. Content Vocabulary • drought • ecotourism • rain forest • savanna • canopy • desertification • deforestation • succulent Academic Vocabulary • annual • enormous Fishponds? Puddles? No! The holes in the ground are actually evaporation ponds in Niger. The water in the ponds evaporates, leaving behind salt. The plentiful sunshine and the mainly dry climate of Niger speed up the evaporation process. Then people gather the salt and take it to market to sell. Read this section to learn about other climates in Africa and how they affect the people who live there. What kind of climate would you prefer to live in? A. Mediterranean B. Tropical C. Highland D. Desert 0% A A. B. C. 0% D. B A B C 0% D C 0% D 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 south of the Sahara has warm or hot climates. Rainfall, however, varies greatly throughout the region. Factors Affecting Climate (cont.) • Africa south of the Sahara 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 south of the Sahara has wet, dry, and temperate climate zones. Factors Affecting Climate (cont.) • Some parts of Africa south of the Sahara 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 Namib Desert in Southern Africa? A. More than 80 inches (203 cm) per year B. None C. Less than 10 inches (25 cm) per year 0% A A. A B. B C.0%C B 0% C Tropical and Dry Climates Most of Africa south of the Sahara 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.) • In a rain forest, vegetation grows at several different levels. – The forest floor has mosses, ferns, and shrubs. – Above these, palms and other trees grow about 60 feet (18 m) high. – The tops of the highest trees form an umbrella-like covering called the canopy, which is alive with flowers, fruits, monkeys, parrots, and snakes. 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.) • The soil on the cleared lands quickly becomes less fertile, causing farmers to clear even more forestland. 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. – Savanna grasslands are home to elephants, lions, rhinoceroses, and giraffes. 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. – Vegetation includes different varieties of trees, thick shrubs, and grasses. Tropical and Dry Climates (cont.) • Steppe areas are threatened by desertification. – Climate changes that bring long periods of extreme dryness and water shortages lead to desertification. – Clearing areas of trees and other vegetation for herding large amounts of livestock can also damage and dry out the land. Tropical and Dry Climates (cont.) • The Sahara Desert in the north has high temperatures and little rain. – Instead of sandy dunes, it contains barren rock or stony plains covered by rocky gravel. – Very little vegetation can live outside the oases and the highlands. Tropical and Dry Climates (cont.) • The Kalahari Desert in Southern Africa is covered by vast stretches of sand. – It has high temperatures and little rainfall. When rains do fall, they are immediately absorbed by the sand, leaving the surface dry. – Certain areas of the Kalahari have trees with long roots that reach the moisture in the deep sand. Tropical and Dry Climates (cont.) • The Namib Desert, along the southwestern coast, is made up of rocks and dunes. – This desert is arid, but temperatures tend to be cooler because of breezes from the ocean. – Fog that forms along the coast reaches the desert and provides moisture to many varieties of succulents, or plants, such as cacti, with thick, fleshy leaves that can conserve moisture. What factors are threatening the savanna plants and animals of Africa south of the Sahara? A. Hunting B. Human settlement C. Pollution D. Both A and B 0% A A. B. C. 0% D. B A B C 0% D C 0% D Moderate Climate Regions Small areas of Africa south of the Sahara have moderate climate regions. Moderate Climate Regions (cont.) • Moderate climates, with comfortable temperatures and enough rainfall for farming, are found in coastal 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.) • Southwestern Africa has a Mediterranean climate in which winters are mild and wet, but the summers are warm and dry. – Most rainfall occurs during the area’s winter months. Moderate Climate Regions (cont.) • Highland climates are found in areas of higher elevation in East Africa. – Temperatures in the highlands are cooler than in surrounding areas because of the higher altitude. – Snow often falls at high elevations, and vegetation is abundant at lower elevations. 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 0% A A. B. C. 0% D. B A B C 0% D C 0% D Landforms • Most of Africa south of the Sahara lies on a series of plateaus. • Africa’s landforms include 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 south of the Sahara 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 south of the Sahara. • 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. escarpment steep cliff at the edge of a plateau with a lowland area below rift valley area of low relief flanked by highland regions that is formed by the moving apart of two of the Earth’s tectonic plates gorge like a canyon, a steep-sided valley formed when a river cuts through land that is being lifted upward industrial diamond diamond used to make drills, saws, or grinding tools to process other materials rather than as a gemstone series arranged in an order and alike in some way principal main or primary drought long period of time without rainfall rain forest dense stand of trees and other growth that receives high amounts of precipitation each year canopy umbrella-like covering formed by the tops of trees in a rain forest deforestation cutting down of forests without replanting new trees ecotourism type of tourism in which people visit a country to enjoy its natural wonders savanna broad grassland in the tropics with few trees desertification process by which dry areas turn into desert succulent type of plant that has thick, fleshy leaves that can conserve moisture annual occurring once a year enormous very big To use this Presentation Plus! product: Click the Forward button to go to the next slide. 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