Geography Grade 10 Student Textbook PDF

GEOGRAPHY STUDENT TEXTBOOK GRADE 10  Take Good Care of This Textbook This textbook is the property of your school. Take good care not to damage or lose it. Here are 10 ideas that help...

GEOGRAPHY STUDENT TEXTBOOK GRADE 10  Take Good Care of This Textbook This textbook is the property of your school. Take good care not to damage or lose it. Here are 10 ideas that help you take care of the book. 1. Cover the book with protective materials. 2. Always keep the book in a clean dry place. 3. Be sure your hands are clean when you use the book. 4. Do not write on the cover or inside pages. 5. Use a piece of paper or cardboard as a bookmark. 6. Never tear or cut out any pictures or pages. 7. Repair any torn pages with paste or tape. 8. Pack the book carefully when you place it in your school bag. 9. Handle the book with care when passing it to another person. 10. When using a new book for the first time, lay it on its back. Open only a few pages at a time. Press lightly along the bound edge as you turn the pages. This will keep the cover in good condition.  GEOGRAPHY STUDENT TEXTBOOK GRADE 10 Writers: Wondafrash Genet Degu (M.A.) Kenate Worku Tabor (Ph.D.) Editors: Sintayehu Teka (M.Sc.) (Content Editor) Kassie Molla (M.A.) (Language Editor) Hirut Woldemichael (M.A.) (Curriculum Editor) Illustrator Agenchw Nega (M.Sc.) Designer Geda Hoka (M.A.) Evaluator Dereje Guteta (Ph.D.) FDRE, MINISTRY OF EDUCATION HAWASSA UNIVERSITY First Published in 2022 by the Federal Democratic Republic of Ethiopia, Ministry of Education, under the General Education Quality Improvement Program for Equity (GEQIP-E) supported by the World Bank, UK’s Department for International Development/ DFID-now merged with the Foreign, Common wealth and Development Office/FCDO, Finland Ministry for Foreign Affairs, the Royal Norwegian Embassy, United Nations Children’s Fund/UNICEF), the Global Partnership for Education (GPE), and Danish Ministry of Foreign Affairs, through a Multi Donor Trust Fund. ©2022 by the Federal Democratic Republic of Ethiopia, Ministry of Education. All rights reserved. The moral rights of the author have been asserted. No part of this textbook reproduced, copied in a retrieval system or transmitted in any form or by any means including electronic, mechanical, magnetic, photocopying, recording or otherwise, without the prior written permission of the Ministry of Education or licensing in accordance with the Federal Democratic Republic of Ethiopia as expressed in the Federal Negarit Gazeta, Proclamation No. 410/2004 - Copyright and Neighboring Rights Protection. The Ministry of Education wishes to thank the many individuals, groups and other bodies involved – directly or indirectly – in publishing this Textbook. Special thanks are due to Hawassa University for their huge contribution in the development of this textbook in collaboration with Addis Ababa University, Bahir Dar University and Jimma University. Copyrighted materials used by permission of their owners. If you are the owner of copyrighted material not cited or improperly cited, please contact the Ministry of Education, Head Office, Arat Kilo, (P.O.Box 1367), Addis Ababa Ethiopia. Printed by: _____________________PRINTING P.O.Box ______________ _________________, ETHIOPIA Under Ministry of Education Contract no. ____________ ISBN: 978-999944-2-046-9  TABLE OF CONTENTS UNIT ONE 1 1. LANDFORMS OF AFRICA 1 1.1 OVERVIEW OF THE WORLD’S MAJOR LANDFORMS 2 1.2 LOCATION AND RELATED FEATURES OF AFRICA 7 1.3 MAJOR LANDFORMS OF AFRICA  8 UNIT SUMMARY 21 REVIEW QUESTIONS 22 UNIT TWO 23 2. CLIMATE OF AFRICA 23 2.1 OVERVIEW OF WORLD CLIMATIC REGIONS AND TYPES 24 2.2 CLIMATE TYPES AND ZONES OF AFRICA 29 2.3 BENEFITS OF CLIMATE FOR LIFE OF PEOPLE OF AFRICA 38 2.4 CLIMATE CHANGE AND ITS CHALLENGES TO AFRICA’S DEVELOPMENT VISION 40 UNIT SUMMARY 43 REVIEW QUESTIONS 45  UNIT THREE 47 3. NATURAL RESOURCE BASE OF AFRICA47 3.1 OVERVIEW OF MAJOR NATURAL RESOURCES OF THE WORLD 48 3.2 MAJOR DRAINAGE AND WATER RESOURCES IN AFRICA 54 3.3 MAIN TYPES OF SOILS AND MINERAL RESOURCES IN AFRICA  62 3.4 MAJOR VEGETATION AND WILDLIFE OF AFRICA 69 UNIT SUMMARY 78 REVIEW QUESTIONS 80 UNIT FOUR 81 4. POPULATION OF AFRICA 81 4.1 OVERVIEW OF WORLD POPULATION GROWTH AND SIZE 82 4.2 AFRICA’S MAJOR DEMOGRAPHIC TRENDS  90 4.3 POPULATION STRUCTURE  101 4.4 DISTRIBUTION AND DENSITY OF AFRICA’S POPULATION 105 4.5 URBAN AND RURAL SETTLEMENT PATTERNS IN AFRICA  106 UNIT SUMMARY 109 REVIEW QUESTIONS 110  UNIT FIVE 111 5. MAJOR ECONOMIC AND CULTURAL ACTIVITIES OF AFRICA 111 5.1 OVERVIEW OF EMPLOYMENT STRUCTURE IN THE WORLD 113 5.2 MAJOR ECONOMIC ACTIVITIES IN AFRICA  115 5.3 POSSIBLE SOLUTIONS TO THE PROBLEM OF UNEMPLOYMENT 121 5.4 AFRICA’S AGENDA 2063 AND ITS IMPLICATIONS  124 5.5 AFRICA’S AGENDA 2063 VIS-À-VIS SUSTAINABLE DEVELOPMENT GOALS (SDGS) 126 5.6 LINGUISTIC AND RELIGIOUS DIVERSITY IN AFRICA 131 UNIT SUMMARY 135 REVIEW QUESTIONS 136 UNIT SIX 137 6. HUMAN – NATURAL ENVIRONMENT INTERACTIONS 137 6.1 OVERVIEW OF GLOBAL POPULATION CHANGE 138 6.2 HUMAN-ENVIRONMENT RELATIONSHIP 141 6.3 INDIGENOUS KNOWLEDGE IN CONSERVATION OF NATURAL RESOURCES IN AFRICA 146 UNIT SUMMARY 148 REVIEW QUESTIONS 149  UNIT SEVEN  151 7. GEOGRAPHIC ISSUES AND PUBLIC CONCERNS IN AFRICA151 7.1 UNPLANNED URBANIZATION 152 7.2 MIGRATION – FACTORS AND IMPACTS ON AFRICA 157 7.3 COASTAL POLLUTION IN AFRICA 159 UNIT SUMMARY 163 REVIEW QUESTIONS 164 UNIT EIGHT 165 8. GEOSPATIAL INFORMATION AND DATA PROCESSING165 8.1 BASIC CONCEPTS OF GEOSPATIAL INFORMATION 166 8.2 SOURCES AND TOOLS OF GEOGRAPHIC DATA 170 8.3 GEOGRAPHIC DATA REPRESENTATIONS 174 8.4 ADVANCES IN MAPMAKING AND THE BIRTH OF GEOGRAPHIC INFORMATION SYSTEM 178 8.5 MAKING AND INTERPRETATION OF GRAPHS, CHARTS AND DIAGRAMS187 UNIT SUMMARY 194 REVIEW QUESTIONS 195 Unit One Landforms of Africa UNIT ONE 1. LANDFORMS OF AFRICA Introduction In the previous grade, you have studied many geospatial information and data processing important features of our country – Ethiopia. are other important issues and skills that you Here in grade ten, you will primarily study will study in this grade. Therefore, successful about our wonderful continent – Africa. Hence, completion of the subject at this grade level this textbook examines the nature of Africa’s helps you to develop an understanding landforms, climate, natural resource bases, and acquire knowledge of basic geographic population, economic and cultural activities. concepts, principles, and theories – focusing Human environment interactions, geographic on Africa. issues and public concerns in Africa ,and Unit Outcomes After completing this unit , you will be able to: develop general idea on the major landforms of the world; identify the major landforms and their spatial distribution in Africa; describe the major landscape features of Africa; and recognize the spatial variations in the distribution of the major landforms in Africa 1  Grade 10 | Geography Main Contents 1.1 OVERVIEW OF THE WORLD’S MAJOR LANDFORMS 1.2 LOCATION AND RELATED FEATURES OF AFRICA 1.3 MAJOR LANDFORMS OF AFRICA 🌐 Unit Summary 🌐 Review Exercise 1.1 OVERVIEW OF THE WORLD’S MAJOR LANDFORMS At the end of this section, you will be able to: explain the formations of major landforms of the world; locate the major landforms of Africa; and explain the spatial variations in the distribution of the major landforms in 🔒 Africa. KEY TERMS մ Continents մ Oceans մ Plateaus մ Landforms մ Peninsula մ Plate tectonic մ Mountains մ Plain մ Volcanic activities Landforms are physical features on the Earth’s surface that form terrain of an area. Mountains, plateaus, and plains are the three major types of landforms. Minor landforms include hills, gorges, valleys, and basins. Activity 1.1 1. How do the major and minor landforms occur? 2 Unit One Landforms of Africa Tectonic plate movement and volcanic activities (internal processes) in the Earth’s interior can create landforms by pushing up mountains and hills. Erosion by water and wind (external processes) can erode land and create minor landforms like gullies, river valleys ,and gorges. Both processes happen over a long period , sometimes millions of years. For example, it took a very long period to cut the deep Abbay Gorge between the towns of Goha Tsiyon in North Shewa, Oromia, and Dejen in East Gojam, Amhara National Regional State. The Abbay Gorge thus cuts down about 1000 m deep between the two towns mentioned above. Figure 1.1: Abbay Gorge at a Point Near Goha Tsiyon and Dejen Towns Activity 1.2 1. What important (specific) landform features can you indicate from Figure 1.1 above? The major landforms (mountains, plateaus and plains) are widely distributed on the earth’s surface. The surface of the Earth is covered by land and water. The landforms make up continents and the water forms oceans. Continents are the largest landmasses in the world. The Earth is divided into seven continents, from largest to smallest are; Asia, Africa, North America, South America, Antarctica, Europe, and Oceania (Australia). 3  Grade 10 | Geography Figure 1.2: Map of the World Activity 1.3 1. In which of the continents is our country – Ethiopia found? 2. Can you indicate Ethiopia on the map in Figure 1.2 above? 3. Can you indicate Japan on the map in Figure 1.2 above? Oceans are large areas of salt water between the continents. Although all the oceans are connected, making them one big ocean, they are divided into five smaller oceans that are separated by their location and the way the water in them moves. These oceans are the Arctic Ocean, the Atlantic Ocean, the Indian Ocean, the Pacific Ocean, and the Southern Ocean. The oceans together cover huge areas of the Earth. They cover seventy one percent of the Earth. The Pacific Ocean is both the largest and the deepest ocean, which covers one-third of the Earth’s surface. Oceans are important factors for creating or forming coastal land features such as island’s, peninsulas, isthmuses. An island is a piece of ground that is completely surrounded by water. Islands can be big or small in any part of the world. The largest island in the world is Greenland. Australia is bigger than Greenland but it is so big that it is called a continent instead of an island. 4 Unit One Landforms of Africa Activity 1.4 1. List sovereign island countries of the world within their respective continents. Africa Asia Europe North America Oceania Two more coastal land features that involve a little land and a lot of water are peninsulas, and isthmus. A peninsula is a piece of land that has water on three sides but it is connected on the fourth side to the mainland. The two well-known peninsulas are Italy and Florida. An isthmus is a narrow strip of land with water on both sides connecting two larger pieces of land. A well-known example is the Isthmus of Panama that connects North America to South America. Activity 1.5 1. What are the three major landforms of the world? 2. Why is it important to study about the landforms? The major landforms of the world create unique areas where people around the world want to know, explore, and visit. These landforms generally divide continents and countries into different physiographic divisions. Let us find out important physiographic regions formed by these landforms in the world. I. Mountain Mountains are the largest elevated and most recognizable landforms on the Earth’s surface. They have steep sides, and high peaks, that stand out from the surrounding land. Around mountains, we may find smaller, less steep landforms called hills. Mountains are usually formed when rock layers are pushed together from opposite sides. Thus, the pressure exerted from the movement forces the land in the middle to rise. The low areas between mountains are called valleys. Mountains may also be formed by volcanic activity when lava and other materials build up on the surface, but 5  Grade 10 | Geography mountains are not the only landforms that can be made by volcanoes. The highest landform on Earth is Mt. Everest. It is a peak in the Himalaya’s Mountain range. It is located between Nepal and Tibet. It measures 8,849 meters above sea level. It is part of the Himalaya Mountain range that runs across several countries in South and Southeast Asia such as India, Pakistan, Nepal, Bhutan, China, and Afghanistan. The mountain range extends 320 to 400 kms in width and 1500 kms in length. The Himalayas were formed about 40 to 50 million years ago when the Indian tectonic plates collided with the Eurasian plate. Indian tectonic plate and the Eurasian plates are continental crust and have the same density. Therefore, when the two plates collide, pushing upwards at their edges formed the Himalayan Mountains. Figure 1.3: Landforms of the World – Mountains Landforms can also exist under oceans in the form of mountain ranges and basins. The Mariana Trench, the deepest landform on Earth, is in the South Pacific Ocean. II. Plain Another major type of landform is plain. Plains are large areas of flat low land with no hills or mountains in them. The Great Plains in the mid United States is a good example of a large plain. Plains are very important areas for crop cultivation and animal husbandry (ranch). III. Plateaus Plateaus are large areas of raised land that are flat on top. Plateaus may be formed by volcanic activity beneath the earth’s surface. Sometimes the pressure of the magma 6 Unit One Landforms of Africa beneath is not strong enough to break through the crust and create a volcano, hence, instead, the land is pushed upwards, plateaus may stand all by themselves in otherwise flat land or may sometimes be close to other plateaus. Activity 1.6 1. Use Figure 1.3 and mark the following; Þ Himalayas Þ Plain areas Þ Mariana trench 1.2 LOCATION AND RELATED FEATURES OF AFRICA At the end of this section, you will be able to: identify the location and size of Africa in relation to the other continents and 🔒 major water bodies. KEY TERMS մ Continents մ Surface area մ Equator մ Sovereign state The continent of Africa is bounded by the Mediterranean Sea, the Red Sea, the Gulf of Aden, the Indian Ocean, and the Atlantic Ocean. It is divided into half by the Equator. Africa is the second largest and second most populous continent on earth after Asia in both cases. Africa’s areal size is 30.37 million Km2, hence, it covers 6% of the Earth’s total surface area and 20% of its land area. Africa’s total population was estimated to be 1.3 billion people in 2020. Therefore, Africa accounts for about 16% of the world’s population. 7  Grade 10 | Geography Figure 1.4: Africa - Location and Countries Africa is home to 54 recognized sovereign states. This division of Africa into almost two equal parts (lengthwise) across the equator makes the climatic and physical conditions in the north repeat themselves in the south. For example, the Kalahari Desert is exactly similar to the Sahara in the southern part of Africa; the Karoo in southern part of the continent matches the Maghreb, and the conditions in the Cape area are almost identical to those of the Mediterranean region in the north. 1.3 MAJOR LANDFORMS OF AFRICA At the end of this section, you will be able to: explain the spatial variations and distributions of the major landforms in 🔒 Africa. KEY TERMS մ Atlas Mountains մ Great Escarpment մ Macroclimate մ Benguela մ Great Karoo մ Microclimate մ Congo Basin մ Highveld մ Rift Valley մ Deserts մ Hills մ The Sahara մ Ecosystems մ Internal processes մ The Sahel մ External processes մ Island մ The Savanna մ Graben մ Isthmus մ Tropical rainforest 8 Unit One Landforms of Africa Landforms are the results of volcanic and tectonic processes. These processes form major landforms of the world as mentioned in the section 1.1 above. Similarly, in Africa there are several recognizable major landforms. Understanding landforms is very important because as part of a landscape, landforms greatly affect human perception and interactions with the environment. Landforms provide a physical context for describing the landscape, topography, and ecological units within the environment. Understanding the physical and historical context of the landscape is necessary in order to understand the temporal and spatial scales of ecosystems. Landforms are ecologically important elements because ecosystems (which consists of all the organisms and the physical environment with which they interact) develop within landform regions, and material and energy flows occur within the landform system. Landforms also affect, modify, and influence climate. The effect can be recognized in both large areas as macroclimate and small areas as microclimate. Effects of landforms on ecosystem patterns and processes include: 1 Landform attributes (elevation, steepness of slope, and aspect) produce many different patterns which determine the ecological potential of an area. 2 Landform regions affect the flow of organisms, energy ,and material. 3 Landform regions affect the spatial pattern of non-geomorphic disturbance by fire and wind. 4 Landforms may resist changes that geomorphic processes create; hence they protect biotic features and processes. In Africa , there are four significant landform regions. Each of these regions contains eight major physical regions: the Atlas Mountains, the Sahara, the Sahel, the savanna, the rainforest, the Rift Valley and African Great Lakes, the Ethiopian Highlands, mountains and desert systems of South Africa. Some of these regions cover large bands of the continent, such as the African massif of the Sahara and Sahara Desert. Table 1.1: Major Regions of Landform in Africa Major Landform Regions Physical Regions African Alpine System Atlas Mountains African massif The Sahara The Sahel The Savanna The Tropical rainforest East African Highlands and rift system The Rift Valley and African Great Lakes The Ethiopian and Eritrean Highlands Southern Africa Platform Mountains and desert systems of Southern Africa 9  Grade 10 | Geography 1.3.1 African Alpine System i. Atlas Mountains: contains a range of mountains in North Africa that extends from Morocco to Tunisia. It forms a series of mountain chains including, the Anti-Atlas, High Atlas, Middle Atlas, Rif Mountains, Tell Atlas, and Sahara Atlas. Figure 1.5: Atlas Mountain The Atlas Mountains make up the Maghrib (meaning ‘west’ in Arabic) region including Morocco, Algeria, and Tunisia. The mountain range extends for more than 2,000 kilometers, from the Moroccan port of Agadir in the southwest, to the Tunisian capital of Tunis in the northeast. The topography of the mountain forms a high divide between the Mediterranean Sea in the north and the Sahara Desert in the south. Activity 1.7 1. The Atlas Mountain covers part of the countries of Algeria, Morocco, and Tunisia. Arrange the countries where the Atlas covers from the largest to the smallest based on Figure 1.4 and Figure 1.5 above. 10 Unit One Landforms of Africa 1.3.2 African Massif I. The Sahara Desert The Sahara is a desert on the African continent. With an area of 9,200,000 square kilometers, it is the largest hot desert in the world. It covers the entire region of North Africa, from the Atlantic coast in the west to the Red Sea in the east. The Sahara borders the Mediterranean Sea and the Atlas Mountains in the north, extending south into Sudan and a region known as the Sahel. The Sahara encompasses whole or large parts of ten countries in North Africa. These countries are Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan, and Tunisia. Figure 1. 6: Desert Landscape Figure 1.7: The Sahara The landscape of the Sahara is covered with sand. The Sahara Desert has enormous quantities of reddish sand dune that is weathered from sandstone. This sand makes up a great sand sea, called an erg. Elsewhere in the Sahara, you find a desert pavement of pebbles on top of vast flat-surfaced sheets of sand. This type of surface is called a reg. Figure 1. 8: Erg - in the Sahara Desert Figure 1.9: Reg - in the Sahara Desert 11  Grade 10 | Geography Activity 1.8 1. Using Figure 1.8 and Figure1. 9, compare and contrast the erg and reg. What are the similarities and differences between them? II. The Sahel The Sahel is a vast semiarid region of North Africa, to the south of the Sahara that forms a transitional zone at the south of the desert and comprises the northern part of the region known as the Sudan. Sahel is an Arabic word (sahil) meaning “shore”. It refers to the 5,000 kilometers stretch of savanna that is the shore or edge of the Sahara Desert. The Sahel spreads west to east from Mauritania and Senegal to Somalia. Countries in the Sahel include: Mauritania, Senegal, Mali, Niger, Nigeria, Burkina Faso, Chad, Sudan and Eritrea. The Sahel lands are grasslands and savannahs, with scrub areas to the north, alternating areas of trees, mainly acacias in the south. Figure 1.10: The Sahel The semiarid grassland of the Sahel has natural pasture (land covered with grass and other low plants suitable for grazing animals), with low-growing grass and tall herbaceous perennials. Hence, there is plenty of forage for the livestock (camel, pack ox, and grazing cattle and sheep). 12 Unit One Landforms of Africa The landscape of the Sahel is similar to the savanna type. However, it tends to merge into desert because of human activities and climate change. Activity 1.9 1. What is desertification? How can desertification be a problem in the Sahel Region? III. The Savanna The Savanna is a transitional region between rainforest and the Sahel grassland. The African savanna region is a tropical grassland with few trees and shrubs (a shrub is a woody plant smaller than a tree and has a very short stem with branches near the ground). The trees in the Savanna region are drought resistant trees. The tree and shrub species in the savanna usually shed their leaves during the dry season. The shedding of the leaves is an adaptation process of the trees to the all year-round hot temperature of the Savanna. This adaptation reduces water loss from the plants. Figure 1.11: The Savanna Region 13  Grade 10 | Geography Figure 1.12: The Savanna Woodland Figure 1.13: Thorn Tree Tall Grass Savanna Based on vegetation types, the Savanna region has two important parts – woodland and thorn tree tall grass Savana. In Savana woodland, the trees are widely spaced because there is not enough soil moisture during the dry season to support a full tree cover (Figure 1.11). The open spacing lets a dense lower layer where grasses develop. The woodland has an open, park-like appearance. In the tropical savanna woodland of Africa, the trees are of medium height. Tree crowns are flattened or umbrella-shaped, and the trunks have thick, rough bark. Some species of trees are xerophytic forms – adapted to the dry environment with small leaves and thorns. Others are broad-leaved deciduous species that shed their leaves in the dry season. Fires occur frequently in the savanna woodland during the dry season, but the tree species are mostly fire resistant. Activity 1.10 1. Why do we find many parks in the Savanna region in Africa? IV. The Tropical Rainforest Tropical rainforests occur both to the north and south of the Equator. The rainforests near the equator are known as equatorial rainforests. These forests are very diverse and contain large number of plant and animal species. Flora is highly diverse in the equatorial rainforests where a square kilometer may contain as many as 100 different tree species as compared to 3 or 4 in the temperate zone. Broadleaf evergreen trees dominate the vegetation cover. Six African countries – Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Gabon, and Equatorial Guinea makeup the Congo Basin of the Tropical Rainforest. Other areas where the rainforest is found include; 14 Unit One Landforms of Africa Ghana, Ivory Coast and Madagascar. Figure 1.14: Typical Rainforest Figure 1.15: Buttress of Tall Tree Figure 1.16: The Tropical Rainforest of Africa The various trees of the tropical rain forests are closely spaced together and form a thick continuous canopy some 25 to 35 meters tall. Sometimes the canopy is interrupted by the presence of very tall trees (up to 40 meters) that have wide buttressed bases for support. Most plants are evergreen with large, dark green, leathery leaves. Epiphytic and herbaceous plants as well as vines (lianas) and ferns are very characteristic of the tropical rainforest. 15  Grade 10 | Geography The rainforest climate is wet all the year or it has a short dry season. Annual rainfall, which exceeds 2000 to 2250 millimeters, is evenly distributed throughout the year. Temperature and humidity are relatively high throughout the year. Decomposition is rapid in the tropical rainforests because of high temperature and high moisture. Meanwhile, due to the frequent and heavy rainfall in the area, tropical soils are subject to extreme chemical weathering and leaching. These environmental conditions also make tropical soils acidic and nutrient poor. Activity 1.11 1. Why do trees in the rainforests grow very tall? 1.3.3 East African Highlands and Rift System I. The Rift Valley and African Great Lakes The Rift Valley of East Africa was formed by normal faulting. It was formed as the land stretched by forces moving in opposite direction creating rupture and splitting apart the land in between. This creates an area called graben. This is an elongated block of the earth’s crust lying between two faults and displaced downward relative to the blocks on either side in a rift valley. graben Figure 1.17: Formation of Graben or Rift The Rift Valley System is a unique feature of Africa’s physiography. It begins from the Red Sea and extends through the Ethiopian landmass to the Lake Victorian region where it subdivides into an east and west segment and continues southward through Lake Malawi to Mozambique. Its total length is estimated to be 5,600 km. The average 16 Unit One Landforms of Africa width of the Rift Valley System ranges between 32 km and 80 km. The Rift Valley lakes are series of lakes in the East African Rift valley that runs through eastern Africa from Ethiopia in the north to Malawi in the south, and includes the African Great Lakes in the south. Many of the lakes are freshwater lake with great biodiversity in them, while others are alkaline or salty lakes. Figure 1.18: The Rift Valley and African Great Lakes The Ethiopian Rift Valley lakes are the northernmost of the African Rift Valley lakes. In central Ethiopia, the Main Ethiopian Rift, also known as the Great Rift Valley, splits the Ethiopian highlands into northwestern and southeastern halves, and the Ethiopian Rift Valley lakes occupy the floor of the rift valley between the two highlands. Lake Victoria lies at an elevation of 1,134 meters above sea level, with an area of 68,800 square kilometers is the largest lake in Africa. It is not in the rift valley, but instead occupies a depression between the eastern and western rifts formed by the uplift of the rifts to either side. II. The Ethiopian and Eritrean Highlands Ethiopia has some of the most spectacular scenery in Africa. Much of the country is set on a high plateau, with a massive central highland complex of mountains divided by the deep Great Rift Valley and a series of lowlands along the periphery (edges) of the higher elevations. The wide diversity of terrain produces regional variations in climate, natural vegetation, soil composition, and settlement patterns. 17  Grade 10 | Geography Figure 1.19: Ethiopian and Eritrean Highlands Ethiopia’s northwestern highlands extend into Eritrea, reaching elevations of more than 2,000 meters above sea level. Eritrea shares the northeast section of the Ethiopian high plateau, which in appearance looks more like a set of rugged uneven mountains. The plateau, also known as the Northwestern Highlands, rise on the western scarp of the Great Rift Valley and projects northward from Addis Ababa in Ethiopia to the Red Sea coastline in Eritrea. It descends to the Red Sea coast in a series of hills. Activity 1.12 1. What is the role of the Rift Valley in the classification of Ethiopia into different physiographic regions? 18 Unit One Landforms of Africa 1.3.4 Southern Africa Platform I. Mountains and Desert Systems of Southern Africa The region of the African continent south of the Congo and Tanzania is named Southern Africa. This landform region has a very diverse landscape. It includes escarpment, mountains, grassland, and desert landscapes. The Tropic of Capricorn runs straight through the middle of the region, indicating that the southern portion is outside the tropics or there is a temperate part in the region. Figure 1.20: Landforms of Southern Africa The Ukhahlamba (Drakensberg) escarpment is the most recognizable landscape in the region. The average altitude of the escarpment is almost 3,000 m above sea level. Two important deserts form large part of southern Africa. The first one is the Kalahari Desert, which lies mainly in Botswana. It is an extensive desert region with an arid mixture of grasslands and sand. When there is adequate rainfall, the grasslands provide excellent grazing for wildlife. The Kalahari is home to game reserves and national parks. The second is Namib Desert, found along the west coast of Namibia. It is 19  Grade 10 | Geography a desert land affected by the cold ocean current of Benguela that borders the area. Hence, the Namib desert was formed partly because of the cold ocean current nearby. The highveld is the portion of the South African inland plateau. The Highveld slopes gently downwards and is bounded by the Great Karoo to the south, the Kalahari Desert to the west and the Bushveld to the north. The highveld is home to some the South Africa’s most important commercial farming areas, as well as its largest concentration of metropolitan centers, especially the Gauteng conurbation, which accommodates one-third of South Africa’s population. The continuation of the Great Escarpment to the south separates the Highveld from KwaZulu-Natal. The southeastern portion of the Great Escarpment or the Ukhahlamba (Drakensberg) forms the boundary between KwaZulu-Natal and Lesotho. Figure 1.21: World Map for Exercises 20  Landforms of Africa UNIT SUMMARY Unit one examined the nature of Africa’s landforms in detail. However, in order to have a better understanding of concepts related to landforms, an overview of the world’s landforms was discussed. The major landforms of the world create very unique areas where people around the world want to know, explore and visit. Hence, landforms generally divide continents and countries into different physiographic regions or divisions. Landforms are the results of volcanic and tectonic processes or internal and external processes that make up landforms. These processes form major landforms of the world. Understanding landforms is very important because as part of a landscape, landforms greatly affect human perception and interactions with the environment. Africa has several recognizable major landforms. The landforms of our continent can broadly be categorized into four major regions – African Alpine System, African massif, East African Highlands and rift system and Southern Africa Platform. Each of the regions has a unique landform feature that distinguishes it from the other. The regions also vary in terms of the area they cover. Hence, the African Alpine System covers a small area compared to the African massif which covers a very large area of the continent. Unit Summary and Review Exercises 21  Grade 10 | Geography REVIEW QUESTIONS 1. Use figure 1.21 to complete the following; i. Mark the continents of the world. ii. Mark the oceans of the world. iii. Mark the Atlas Mountains. 2. What are the major landforms of the world? __________________________________________________________ __________________________________________________________ _________________________________________________________ 3. Why is it important to study about landforms? __________________________________________________________ __________________________________________________________ _________________________________________________________ 4. In which of the major landforms of Africa are many of the national parks found? __________________________________________________________ __________________________________________________________ _________________________________________________________ 5. What important landform feature divides Ethiopia into different physiographic regions? __________________________________________________________ __________________________________________________________ _________________________________________________________ 22  UNIT TWO CLIMATE OF AFRICA UNIT TWO 2. CLIMATE OF AFRICA Introduction In unit one, you have learnt about landforms day, the state of the atmosphere with respect of Africa. In this unit , you will study about to heat or cold, wetness or dryness, calm or the climate of Africa. The first section of the storm, clearness or cloudiness. unit presents the climate types or zones and Climatic zones are spacious areas with regions of the world. In the second section, a climatic similarity. The climate zones you will study the features of the climate of spread in an east-west direction around the Africa. Earth and can be classified using different Climate is an average of weather conditions climatic parameters. Climatic region refers in a place over a long period – 30 years or to a continuous geographic area in which more. It represents the sum of all interacting similar climate characteristics are observed. atmospheric processes over a given period. Average temperature is the most important Weather, on the other hand, refers to a short- factor in determining climate regions of the term atmospheric condition such as the world, although other weather aspects like temperature and precipitation on a certain precipitation play roles. 23  Grade 10 | Geography Unit Outcomes After completing this unit , you will be able to: assess the climatic regions and climate types of the world; compare climatic regions within Africa; examine how climate provides substantial benefits for the life of people in Africa; and analyze the challenges posed by climate change on the development of Africa. Main Contents 2.1 OVERVIEW OF WORLD CLIMATIC REGIONS AND TYPES 2.2 CLIMATE TYPES AND REGIONS OF AFRICA 2.3 BENEFITS OF CLIMATE FOR THE LIFE OF PEOPLE IN AFRICA 2.4 CLIMATE CHANGE AND ITS CHALLENGES TO AFRICA’S DEVELOPMENT VISION 🌐 Unit Summary 🌐 Review Exercise 2.1 OVERVIEW OF WORLD CLIMATIC REGIONS AND TYPES At the end of this section, you will be able to: identify the major climate types and regions of the world; and 🔒 distinguish the different classification schemes of world climate. KEY TERMS մ Climate classifications մ Climate regions մ Climate մ Weather մ Climate zones 24 UNIT TWO CLIMATE OF AFRICA Global climate is a description of the climate of the Earth as a whole, with all the regional differences averaged. The world has several climatic zones. Geographers and climatologists defined climatic region based on different climatic elements. In fact, the Earth’s climate is driven by energy from the sun which arrives in the form of radiation. Activity 2.1 1. How many world climate regions and types do you know? How do climate scientists and geographers classify world climates into different types and regions? 2.1.1 Climate Classifications 👩 Why classification? How do scientists classify world climates into different types? Climate classifications help people know what types of conditions a region usually experiences throughout the year. Rather than describing the full range of conditions observed in a region over each month or season of a year, a classification scheme can communicate expected conditions using just two or three terms. Knowing a region’s climate classification can be useful when choosing building materials for protection and durability, or when considering what crops are likely to thrive in a region. For tourists, knowing a location’s climate classification can help them select and pack appropriate clothing. There are various classification schemes used by climatologists for categorizing world’s climate into different regions. Perhaps the first attempt at climate classification was made by the ancient Greeks, who divided each hemisphere into three zones: torrid (tropical), temperate, and frigid. 25  Grade 10 | Geography Figure 2.1: World Climate Zones According to Ancient Greeks Since the beginning of the twentieth century, however, many climate-classification schemes have been devised. Long-term records of temperature and precipitation reveal climate patterns across continents, delineating them into climate regions. Class names for classification systems based on weather patterns often include geographical names such as polar, tropical, continental, and marine. These terms are modified by terms describing temperature and moisture, or the intensity of weather during summer or winter. The descriptors that are used in this method of classification include moist or dry, warm or cold, and temperate or severe. Today, climate scientists split the earth into approximately five major types: tropical, dry, temperate, continental, and polar considering a variety of factors including altitude, air pressure, wind patterns, latitude and geographical characteristics such as mountains and oceans. One of the most widely used classification schemes is made by the German Climatologist and Botanist Wladimir Köppen (1846-1940). He divided the world’s climates into categories based upon general temperature profiles related to latitude. The Köppen classification uses easily obtained data: mean monthly and annual values of temperature and precipitation. Köppen believed that the distribution of natural vegetation was the best expression of an overall climate. Köppen recognized five principal climate groups, each designated with a capital letter: 26 UNIT TWO CLIMATE OF AFRICA A (humid tropical), B (dry), C (humid middle-latitude, mild winters), D (humid middle-latitude, severe winters), and E (polar), and H (highland). Four groups (A, C, D, E) are defined by temperature. The fifth, (group B), has precipitation as its primary criterion, while H is determined by altitude. Figure 2.2: Map of Köppen’s Five Principal Climate Groups 2.1.2 World Climate Zones and Regions Activity 2.2 1. Be in a small group and discuss the characteristics of each one of the climate types in Köppen’s classification scheme. What other classification schemes do you know? Climate zones are areas with distinct climates, which occur in the east-west direction around the Earth, and they can be classified using different climatic parameters. Generally, climate zones are belt-shaped and circular around the poles (see Figure 2.3). In some areas, climate zones can be interrupted by mountains or oceans. The world’s climate pattern reflects a regular and dependable operation of the major climate controls. 27  Grade 10 | Geography The solar radiation reaches the ground on different parts of the Earth at different angles. On the equator, the sunlight reaches the ground almost perpendicularly, whilst at the poles the angle of the Sun is lower or even under the horizon during the polar night. Throughout the seasons, the position of the Sun to the Earth changes and thus the angle of incidence of the sunlight also changes. The angle of the Sun at noon varies from perpendicular (90°) within the tropics up to horizontal (0° = Sun does not or only partially appear on the horizon) within the polar circle. Thus, the sunlight warms up the Earth around the equator much more strongly than at the poles. Due to temperature differences caused by the differences in radiation, recurring climatic conditions develop. There are four major global climate zones: 1. Tropical Zone from 0°– 231/2° (between the tropics) - In the regions between the equator and the tropics (equatorial region), the solar radiation reaches the ground nearly vertically at noontime during almost the entire year. Thereby, it is very warm in these regions. Through high temperatures, more water evaporates and the air is often moist. The resulting frequent and dense cloud cover reduces the effect of solar radiation on the ground temperature. 2. Subtropics Zone from 23.5°– 40° - The subtropics receive the highest radiation in summer, since the Sun’s angle at noon is almost vertical to the Earth, whilst the cloud cover is relatively thin. These regions receive less moisture (see trade winds), which increases the effect of radiation. Therefore, most of the deserts in the world are situated in this zone. In winter, the radiation in these regions decreases significantly, and it can temporarily be very cool and moist. 3. Temperate Zone from 40°– 60° - In the temperate zone, the solar radiation arrives at a lower angle, and the average temperatures here are much cooler than in the subtropics. The seasons and day length differ significantly in the course of a year. The climate is characterized by less frequent extremes, more regular distribution of the precipitation over the year and a longer vegetation period – therefore, it is named as “temperate”. 4. Cold Zone from 60°– 90° - The polar areas between 60° latitude and the poles receive less heat through solar radiation, since there is very low angle of the Sun. Because of the changes of the Earth axis angle to the Sun, the day length varies most in this zone. For instance, in the summer, polar days occur. Vegetation is only possible during a few months per year and even it is often sparse. The conditions in these regions make life very challenging. The characteristics of the climate zones change with great altitude differences within a small area, like in mountain areas, since temperatures decrease rapidly with altitude. 28 UNIT TWO CLIMATE OF AFRICA Figure 2.3: World Climate Zones 2.2 CLIMATE TYPES AND ZONES OF AFRICA At the end of this section, you will be able to: identify the major climate types and regions of Africa; and distinguish the controls of the climate of Africa. 🔒 KEY TERMS մ Continental climates մ The ITCZ մ Equatorial climate մ The tropical wet-and-dry region մ Maritime climates մ Tropic of Cancer մ Ocean current մ Tropic of Capricorn Activity 2.3 1. What are the major types and zones of climate in Africa? Which factors determine the types of climates in Africa? 29  Grade 10 | Geography The climate of Africa is characterized by a range of climates such as the equatorial climate, the tropical wet and dry climate, the tropical monsoon climate, the semi- arid climate (semi-desert and steppe), the desert climate (hyper-arid and arid), and the subtropical highland climate. Temperate climates are rare across the continent except at very high elevations and along the fringes of the continent. In fact, the climate of Africa is more variable in rainfall amount than in temperatures, which are consistently high. African deserts are the sunniest and the driest parts of the continent, owing to the prevailing presence of the subtropical ridge with subsiding, hot, dry air masses. Africa holds many heat-related records: the hottest extended region year-round, the areas with the hottest summer climate, the highest sunshine duration, and more. Activity 2.4 1. Explain the relationship between position of Africa and its climate types. Owing to Africa’s position across equatorial and subtropical latitudes in both the northern and southern hemisphere, several different climate types can be found within it. The continent mainly lies within the tropical zone between the Tropic of Cancer and the Tropic of Capricorn, hence its interesting density of humidity. Precipitation intensity is always high, and it is a hot continent. Warm and hot climates prevail all over Africa, but mostly the northern part is marked by aridity and high temperatures. Only the northernmost and the southernmost fringes of the continent have a Mediterranean climate (see Figure 2.4). The equator runs through the middle of Africa, as do the Tropic of Cancer and the Tropic of Capricorn, making Africa the most tropical of all the continents. Africa’s position is relatively unique in the sense that it almost has a mirror image of climate zones to the north and South of the Equator with regard to latitude. When considered in detail, the movement of air masses and their effects provide the basis for a division of the continent into eight climatic regions. These are the equatorial (tropical wet), semiarid, tropical wet-and-dry, hot desert, Mediterranean, humid subtropical marine, warm temperate upland, and mountain regions. 30 UNIT TWO CLIMATE OF AFRICA 2.2.1 Types and Characteristics of Climate Zones in Africa Climate is regulated by the apparent movement of the sun between the two tropics and the associated movement of winds. Meanwhile, north or south of the Equator the climate tends to change similarly. This gives rise to symmetrical climatic zones in Africa consisting of the central zone of equatorial climate, tropical zones, hot deserts ,and Mediterranean zones. Details of the types and characteristics of each climate zones are presented below. I. The Equatorial Climate Region The equatorial climate is experienced in the lowland area between latitudes 50N and 50S of the equator. This covers mainly parts of Central Africa which includes the Democratic Republic of Congo, Gabon and Cameroon. It is also experienced in the Southern part of Nigeria, Ghana, Benin and Sera Leone. Highland and coastal areas, especially in Eastern Africa, experience modified equatorial climate where the temperature is much lower than it is experienced in the true equatorial climate. In the Equatorial climate, temperatures are very high throughout the year averaging about 26°C, the hottest months in the year are March and September when the sun is overhead at the equator. The diurnal temperature range is very low, about 3°C. There is often heavy cloud cover and the humidity is high throughout the year. This region mainly receives convectional rainfall. II. The Tropical Wet-and-Dry Region The tropical wet-and-dry region is often called the savanna climatic region; this implies, incorrectly, that all areas with savanna vegetation have this type of climate. This region covers a little less than half of the total surface area of the continent, extending toward the Equator from the semiarid areas. The great distinguishing feature of this climatic region is the seasonal character of its rainfall. During the period of high sun, the maritime air masses produce up to six months of rainfall, the length of the rainy season depending on the nearness to the Equator. The rest of the year is dry. In a few places, for example, on the coast of Mauritania and Senegal, there is also a little rainfall in the period of low sun. As in the desert and semiarid climatic zones, mean monthly temperatures show less variation than daily temperatures. In western Africa, the period of low sun corresponds to the harmattan season. The harmattan is a warm, dry, northeasterly or easterly wind that blows out of the southern Sahara and is frequently laden with large quantities of sand and dust. 31  Grade 10 | Geography Regions with the equatorial, or tropical wet, type of climate, or variants, are the wettest in Africa. There are two peak periods of rainfall corresponding to the double passage of the inter-treopical convergence zone (ITCZ). Because areas with an equatorial climate are constantly covered by warm maritime air masses, variations in their monthly and daily temperatures are less pronounced than in the tropical wet-and-dry regions. Marked variations in the rhythm of equatorial climate sometimes occur. For example, the rainfall may be monsoonal or the second rainy season may not exist at all. However, the most notable variation can be observed on the western African coast from around Cape Three Points in Ghana, eastward to Benin, where the bimodal rainfall regime prevails, and the total annual precipitation is less than 1,000 mm. Some of the explanations about these variations include: the presence of a cold body of water off-shore chills the lower of the maritime air mass and makes it stable; the body of cold air that forms offshore diverts the incoming airstreams to the west and east of the anomalously dry area; there is a strong tendency for the winds to blow parallel to the shore during the rainy seasons; the absence of highlands deprives the region of Orographic (mountain) rainfall; fluctuations in the offshore moisture-bearing winds occur during the rainy season and reduce rainfall; and that local meteorological peculiarities of thunderstorms contribute to the reduction in rainfall. In Eastern Africa, the tropical climate type is experienced in Sudan, Ethiopia, Kenya, Tanzania and Somalia. Similarly in Central Africa, it is experienced in Zambia, Malawi, Angola, Namibia, Botswana and Zimbabwe. In the northern and southern extremities of the continent, there is a dry summer subtropical, or the Mediterranean type of climate. Rain falls only in winter (December– January in North Africa, June–July in Southern Africa), although in some localities it may fall in autumn (September in North Africa, April in Southern Africa). Mean monthly temperatures are lower than in tropical climates, dropping to about 10 °C in winter, while summer (June–July in North Africa, and December–January in Southern Africa) temperatures may sometimes exceed those of tropical climates. Clear and blue skies are the common characteristics of this climate region. III. Semi-arid Climatic Region This region fringes the desert areas and include the greater part of the land south of the Zambezi River. They differ from true desert regions in being just within reach of the ITCZ in the course of its seasonal movement and therefore receiving more rainfall. Temperatures are about the same as those in the desert regions. 32 UNIT TWO CLIMATE OF AFRICA IV. The Hot Desert Climatic Region Hot deserts are places where there is little or no rainfall. The hot desert region consists of the Sahara and Kalahari deserts, which are always under the influence of dry continental tropical air masses, and the northern Kenya–Somali desert, the aridity of which is principally caused by the stable nature of the maritime air masses that pass over it throughout the year. The stability of these maritime air masses is induced by their passing over the cool body of water offshore. In addition to aridity, the desert climate is characterized by high mean monthly temperatures; the diurnal (daily) temperature range is, however, greater than the annual range of the mean monthly. The daytime temperatures are extremely high; temperatures usually range between 30ºC - 40ºC, some places in the Sahara Desert experience above 40°C, the highest ever recorded temperature in the region, and also in the world, was 58°C in Azizia, Libya. At night, temperatures are very low, dropping to below 10º C. The skies are clear and because of this, the heat received from the sun during the day is quickly lost back into the atmosphere at night. V. Mediterranean Climate Region This climate is also called Warm Temperate Western Margin Climate and it is experienced in very small areas of the continent. The Mediterranean climate is best developed on the shores of the Mediterranean Sea. It is also experienced in the South- Western tip of Africa. Temperatures in the Mediterranean climate region range from 10º C in winter to about 21º C in summer. These areas lie in the path of westerly winds. In the summer season, winds blow from the land to the sea. Therefore, they are dry winds. Winters are wet because cool moist winds blow towards the land from the sea. The influence of moist westerly winds also makes the winters mild. The average amount of rainfall each year is about 500-750 mm. VI. The Warm Temperate East Coast Climate Region The climate is experienced between latitudes 30º - 40º North of the Equator and 30º - 40º South of the Equator. It is experienced along the Eastern coast of South Africa, especially in Natal and Cape Provinces, as well as in Mozambique. These areas are under the strong influence of the warm Mozambique current and the warm southeast trade winds. Summer temperatures are generally high with an average of about 26ºC. Winter temperatures are low, averaging about 10ºC. Annual rainfall is between 1000 - 1500 mm per year but it decreases as one moves westwards into the interior. 33  Grade 10 | Geography VII. Warm Temperate Continental Climate Region This climate is mainly experienced in the interior of South Africa, between the Drakensberg Mountains and the Kalahari Desert. The rainfall amount is generally low because the area is inland and the winds blowing from the sea reach here when they are already dry. Most of the rain falls during the winter season and averages about 700 mm per year. The Eastern areas are wetter than those in the West which are close to the Kalahari Desert. The annual temperature ranges from about 26ºC in summer to about 10ºC in winter. VIII. The Mountain Climatic Region This climate region includes the high mountain areas of Kenya, Ethiopia and the lakes region of East Africa. In some respects, the climate is similar to the warm temperate upland climate, except the temperatures are even lower and snow occurs on the tops of the highest peaks, such as Kilimanjaro. The area receives more rainfall than the surrounding areas. It mostly receives relief rainfall, formed as the warm moist winds are forced to rise up the highlands. The highest amount of rainfall is received on the windward slopes. At the lower slopes, the mountains are warmer and wetter. The slopes facing away from the sea are called leeward or rain shadow slopes. They receive little or no rain. The winds here are descending and have a cooling effect. Temperature decreases with an increase in altitude. At the very top of high mountains, temperatures are below freezing point. Figure 2.4: Climate Zones of Africa based on Köppen’s Classification 34 UNIT TWO CLIMATE OF AFRICA 2.2.2 Factors Controlling Climate of Africa Activity 2.5 1. List the factors that control the climate of Africa. How do these factors control the continent’s climate? There are several factors that influence the climate of the African continent. These include angle of the sun, latitude, air pressure, wind system and the Intertropical convergence zone (ITCZ), major ocean currents, land and water (maritime versus continental) influence, and altitude. These factors determine the amount of temperature and precipitation. Below is the description of each one of the factors. I. Latitude and its influence on Solar Radiation received Africa straddles the Equator from 37⁰ N to 34⁰ S, hence it lies within the tropics. Variations in the receipt of solar energy and temperature differences are largely a function of latitude. Temperature is high throughout the continent because of the continent’s location relative to Equator. As latitude increases, the sun shines more obliquely and provides less energy. The equator, however, faces the sun’s rays directly, so the climate is warm year-round. II. Pressure Systems, Winds, and the Intertropical Convergence Zone (ITCZ) Located on about Latitude 30o North and South of the Equator are Sub-tropical High- Pressure Belts that dictate surface wind patterns and influence rainfall and temperature regimes on the continent. The Subtropical High-Pressure Systems on both sides of the Equator generate two wind systems that converge on the equator in a zone termed as Inter-Tropical Converge Zone (ITCZ). From the north, Subtropical High-Pressure Belt zone blows the Northeast Trade Winds (locally called Harmattan). The Harmattan is dry and cool and blows over Sub-Saharan Africa from about November to April. From the south Sub-tropical High Pressure belt zone blows the Southwest Trade Winds (locally called Monsoon). 35  Grade 10 | Geography Figure 2.5: The Position of I.T.C.Z in Africa January and July The Monsoon winds are moist and bring rainfall to the coasts of West Africa. The African continent does not extend much beyond 35o of latitude from the equator. The implication is that the range of climatic conditions is limited and that the general direction of wind movement is towards the equator (or in more accurate terms towards the inter-tropical convergence zone - ITCZ). The ITCZ shifts with the seasonal movement of the sun across the tropics: In June: the northern summer season, the ITCZ is located at about 13 degrees of latitude in North Africa at the southern boundary of the Sahara. In December, the Northern winter season, the ITCZ moves southward along the West African Coast and to the northern and eastern margins of the Congo basin and continues to Madagascar. Movements in the ITCZ are closely related to the distribution of rainfall and climatic zones. The climatic zones assume symmetry around the equator, although the high altitudes in some parts of the continent and the adjacent disturb the symmetry. III. Major Ocean Currents Winds that tend to blow persistently over the ocean tend to drag a thin surface layer of the water in their direction of flow. This layer of ocean water called Ocean Current dictates the temperature and moisture characteristics of the wind and the coastal regions over which the wind blows. When ocean currents blow from low 36 UNIT TWO CLIMATE OF AFRICA latitudes (near to the equator) towards higher latitudes (towards the pole) the currents carry Warm ocean water into relatively cool regions. Such an ocean current is called Warm Ocean Current. Warm Ocean Currents supply moisture to winds blowing over them to develop rainfall on the adjacent coasts. In Africa, Warm Ocean Currents include Warm Guinea Currents - in West Africa, Warm Mozambique Currents – in Southeast Africa. The cool surface of Cool Ocean Currents causes moisture in winds blowing over them to condense and form fogs, etc. The winds are deprived of their moisture so they tend to absorb rather than deposit moisture at the adjacent coasts. Cool currents, therefore, cause dry conditions and in Africa the Cool Canary Currents - the western coast of the Sahara Desert, the Cool Benguela Currents – the Western coast of Kalahari Desert. The cool ocean currents tend to create rich fishing grounds. Rich fishing grounds exist along the Morocco and Spanish Saharan Coasts that are washed by the Cool Canary Currents. The Namibian coast that is washed by the Cool Benguela current also has rich fishing grounds. IV. Distribution of Land and Water Large water bodies such as the Ocean and huge lakes modify climates in adjacent lands. In the continental interior, where there are no large bodies of water, temperatures get very warm in summer or during the day. The land is solid, so it heats up more rapidly during the day. The compact nature of the land means that only a thin surface gets heated. As a result, heat absorbed into the thin layer of surface rocks is released very rapidly. The land surface is, therefore, very cool at night and in winter. The interior location does not also allow rainfall to reach such places thereby creating warm, humid, hot and dry climates. These extremities in climate affect all states located in the interior of continents. Such climates are called Continental Climates as against Maritime Climates experienced on lands located along coasts. In places such as Timbuktu in Mali the diurnal and annual ranges in temperature are very high because of continentality. V. Altitude Since energy from the sun is transformed into heat on the surface of the earth, air temperature decreases with altitude at an average rate of 6.4 oC per 1000 meters. This change in temperature with altitude is called the Lapse Rate. Because of this decrease in temperature with height, mountainous regions such as the Ethiopian highlands have very cool temperatures. Very high peaks such as Mountain Kilimanjaro located along the equator even have permanent snow cover. 37  Grade 10 | Geography While these factors help to account for the broad climatic patterns of African continent, there are nevertheless numerous local variations to be found from place to place within the same climatic zone. 2.3 BENEFITS OF CLIMATE FOR LIFE OF PEOPLE OF AFRICA At the end of this section, you will be able to: explain the benefits of climate for the life of people of Africa. 🔒 KEY TERMS մ Agriculture մ Surface-water supply մ Human health մ Temperature extremes մ Natural resources Activity 2.6 1. In a group discuss the benefits of climate to the life of the people of Africa. 2. Debate on the benefits and disadvantages of climate on the life of the people of Africa. Climate affects nearly every aspect of our lives from our food sources to our transport infrastructure; from what clothes we wear, to where we go for recreation. It has a huge effect on our livelihood, our health, and our future. People’s settlement and living are hugely associated with climate types. For instance, some places are overpopulated due to the better climate and associated factors. On the other hand, regions of extreme climatic conditions like the deserts, rainforests, and polar regions have fewer people. Africa is a continent with a diversity of climate landscapes. It has a climate that ranges from intense heat to bitter cold in its different parts. This diversity in turn influences 38 UNIT TWO CLIMATE OF AFRICA the living style of people including settlement patterns, livelihood options, resource endowments, health ,and wellbeing. The relationship between climate, physical resources ,and socio-economic condition of people in Africa is briefly presented in the following section. 2.3.1 Climate and Agriculture in Africa It is indisputable that agriculture is the backbone of Africa’s economy and accounts for the majority of livelihoods across the continent. Agriculture is an extremely important sector on the African continent, on average accounting for 70% of the labor force and over 25% of the Gross Domestic Product (GDP). Agriculture has always been deeply dependent on the weather, with farmers needing a steady mixture of sun, warmth, and rains to reliably produce the crops they need. The bulk of agricultural systems in Sub-Saharan Africa are highly climate-dependent: the region is marked by a strong dependence on rain-fed agriculture and natural resources. Africa is one of the continents that are most highly affected by climate change for two reasons: its geographical characteristics of having a major land lying across the warming tropics, and the limited human, social, and economic capacity that African countries have to adapt to the impacts of climate change. A change in a climate, therefore, exacerbates the complexity of issues (such as few technological inputs, the majority of Africa’s farmers working on a small-scale or subsistence level and have few financial resources, limited access to infrastructure, and, etc.) in the continent. 2.3.2 Climate and Health in Africa Climate change has widespread effects on human health by impacting both environmental and social determinants. Humans have understood the importance of climate to human health since ancient times. In some cases, the connections appear to be obvious. For instance, a flood can cause drownings, a drought can lead to crop failure and hunger, and temperature extremes pose a risk of exposure. In other cases, the connections are obscured by complex or unobserved processes, such that the influence of climate on a disease epidemic or a conflict can be difficult to diagnose. In reality, however, all climate impacts on health are mediated by some combination of natural and human dynamics that cause individuals or populations to be vulnerable to the effects of a variable or changing climate. 39  Grade 10 | Geography Africa is commonly described as a “climate-vulnerable” continent in which rainfall variability, hydrological extremes, and anthropogenic climate change have the potential to inflict significant harm on a large population. 2.3.3 Climate and Water Resources in Africa Water is the most important of all natural resources. Without water ,life would not be able to thrive on the Earth. It has been argued that the level of streams, flow of streams/ rivers, the volume of underground water and the like all depend on types of climates and water availability. Therefore, persistent climate change may lead to shrinkage in the surface-water supply as well as the quantity and regularity of streams and rivers, and water supplies in Africa. Activity 2.7 1. What are the benefits of climate to other physical and socio-economic aspects of Africa? Mention the role of climate in determining lifestyle, tourism development, fishing, and natural vegetation in the continent? 2.4 CLIMATE CHANGE AND ITS CHALLENGES TO AFRICA’S DEVELOPMENT VISION At the end of this section, you will be able to: explain the major challenges of climate change on African development vision. 🔒 KEY TERMS մ Africa’s development vision մ Development policies մ Climate change մ Millennium Development մ Climate system Goals (MDGs) մ Climate variability 40 UNIT TWO CLIMATE OF AFRICA In many cases climate variability and climate change are interchangeably used. However, there is a clear demarcation between the two. Variability may be due to natural internal processes within the climate system or to variations in anthropogenic (caused by human) external forcing. In other words, climate variations occur with or without our actions. It is critical to assess precisely which human actions affect climate and those that do not. Climate change, on the other hand, is a change in the state of the climate system, identified by changes in the average conditions and the variability of its properties, that persists for an extended period, typically decades or longer, due to natural and/or anthropogenic processes and drivers. Activity 2.8 1. What is climate change? How does climate change affect Africa’s development vision? Climate change in Africa is an increasingly serious threat for Africans as Africa is among the most vulnerable continents to climate change. Anthropogenic climate change is already a reality in Africa, as it is elsewhere in the world. According to the Intergovernmental Panel on Climate Change (IPCC), the vulnerability of Africa to climate change is driven by a range of factors that include weak adaptive capacity, high dependence on ecosystem goods for livelihoods, and less developed agricultural production systems. The risks of climate change on agricultural production, food security, water resources and ecosystem services will likely have increasingly severe consequences on lives and sustainable development prospects in Africa. Most studies on the potential impact of climate change have predicted that Africa is likely to experience higher temperatures, rising sea levels, changing rainfall patterns and increased climate variability, all of which could affect much of its population. The actual and potential impacts of climate change in Africa are large and wide-ranging, affecting many aspects of people’s everyday lives. Many climate models predict negative impacts of climate change on agricultural production and food security in large parts of Sub-Saharan Africa (SSA). Higher temperatures, the drying up of soils, increased pest and disease, shifts in suitable areas for growing crops and livestock, desertification, floods, deforestation, and erosion are all signs that climate change is already happening. Therefore, this indicates that climate change is one of the greatest environmental, social and economic threats facing Africa. The impact of climate change is more serious on the world’s poorest countries, most of which are found in Africa. Poor people already live on the frontlines of pollution, disaster, and degradation 41  Grade 10 | Geography of resources and land. For them, adaptation is a matter of sheer survival. Unfortunately, despite growing concern, no exact and reliable figures are available to quantify the economic costs of the negative impacts of climate change in Africa for either individuals or society as a whole. As far as development is concerned, climate change will have a strong impact on Africa’s ability to achieve the Millennium Development Goals (MDGs) and the Africa 2063 goal and on its development policies in general, with increased pressure on agriculture, water supply and demand, health, and political stability. In general, African has been seriously affected due to the following reasons. First, the African society is very closely coupled with the climate system, hundreds of millions of people depend on rainfall to grow their foods. Second, the African climate system is controlled by an extremely complex mix of large-scale weather systems. Third, the degree of expected climate change is large. The two most extensive land-based end- of- century projected decreases in rainfall anywhere on the planet occur over Africa, particularly in North and South Africa. Finally, the capacity for adaptation to climate change is low. 42  CLIMATE OF AFRICA UNIT SUMMARY Weather and climate are the two essential concepts interchangeably used. However, there is a clear boundary in meaning between the two. Weather refers to a short-term atmospheric condition – for example, the temperature and precipitation on a certain day, the state of the atmosphere with respect to heat or cold, wetness or dryness, calm or storm, clearness or cloudiness. On the other hand, a climate is an average of weather conditions in a place over a long period – 30 years or more. A climate, however, is more than just a generalization of weather, it includes extreme events and probabilities, it is the sum of all statistical weather information describing a place or region. There are various classification schemes used by climatologists for categorizing the world’s climate into different regions. The ancient Greeks classified the world climates into three: torrid, temperate, and polar. Later, since the beginning of the twentieth century, however, many climate-classification schemes have been devised that used long-term records of temperature and precipitation. The most widely used and popular climate classification scheme is developed by the German Climatologist and Botanist Wladimir Köppen (1846-1940). Köppen classified the world climate regions into five. He used temperature for four of the climate regions and precipitation for the fifth one. In general, there are 4 (four) major global climate zones; namely the Tropical zone from 0°– 231/2° (between the tropics), the Subtropics from 231/2°– 40°, the Temperate zone from 40°–60°, and the Cold zone from 60°–90°. The characteristics of the climate zones change with great altitude differences within a small area, like in mountain areas, since temperatures decrease rapidly with altitude. The climate of Africa is characterized by a range of climates such as the equatorial climate, the tropical wet and dry climate, the tropical monsoon climate, the semi- arid climate (semi-desert and steppe), the desert climate (hyper-arid and arid), and the subtropical highland climate. The equator runs through the middle of Africa, as do the Tropic of Cancer and the Tropic of Capricorn, making Africa the most tropical of all the continents. Its position is relatively unique in the sense that it almost has a mirror image of climate zones to the north and south of the Equator with regard to latitude. There are a number of factors that influence the climate of the African continent. These include the angle of the sun, latitude, air pressure, wind system and the ICTZ, major ocean currents, land and water (maritime versus continental) influence, and altitude. These factors determine the amount of temperature and precipitation. Unit Summary and Review Exercises 43  Grade 10 | Geography The movement of air masses and their effects provide the basis for a division of the continent into eight climatic regions. These are the equatorial (tropical wet), semiarid, tropical wet-and-dry, hot desert, Mediterranean, humid subtropical marine, warm temperate upland, and mountain regions. Climate affects nearly every aspect of our lives from our food sources to our transport infrastructure; from what clothes we wear, to where we go for recreation. It has a huge effect on our livelihood, our health, and our future. People’s settlement and living are hugely associated with climate types. However, climate change in Africa is an increasingly serious threat for Africans as Africa is among the most vulnerable continents to climate change. Many climate models predict the negative impacts of climate change on agricultural production and food security in large parts of sub- Saharan Africa (SSA). As far as development is concerned, climate change will have a strong impact on Africa’s ability to achieve the Millennium Development Goals (MDGs) and the Africa 2063 goal and on its development policies in general, with increased pressure on agriculture, water supply and demand, health, and political stability. One of the most important reasons for this is the continent’s low adaptive capacities to withstand the ever-changing climate conditions. 44  CLIMATE OF AFRICA REVIEW QUESTIONS 1. What characteristics do we use to differentiate between one climatic zone and another? ______________________________________________________________ ______________________________________________________________ ________________________ 2. Africa is the only continent that can be regarded as “a mirror image of each hemisphere” with regard to climate zones. Elaborate this statement with examples. ______________________________________________________________ ______________________________________________________________ ________________________ 3. Identify the three major ocean currents that affect the shores of African continent and discuss how they control the local climate system. Indicate on a map the parts of Africa affected by the impacts of the ocean currents. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ____________________________________ 4. What is the ITCZ? Discuss the processes and mechanisms in which the ITCZ governs the climate types and zones in Africa. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ____________________________________ Unit Summary and Review Exercises 45  Grade 10 | Geography 5. Draw the map of Africa and show the distribution of each climate zones using colors. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ____________________________________ 6. List the major contribution of climate to the livelihood of people in African. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ____________________________________ 7. What are the causes of climate change in Africa? In groups of five students in a class, list out and explain the major causes of climate change in the continent. Discuss also on the indicators of climate change in Africa. ______________________________________________________________ ______________________________________________________________ ________ 46 Unit Three Natural Resource Base of Africa UNIT THREE 3. NATURAL RESOURCE BASE OF AFRICA Introduction In the previous unit, you have carefully studied support in the form of both consumptive about the climate of Africa. In this unit ,you use and public-good services. However, the will study the natural resource base of Africa. sustainable and wise use of natural resources Therefore, this unit examines Africa’s natural is more important than the existence of the resources endowment. However, in order to resources. The major life sustaining resources better understand and give due attention to of the world are water, soil, forest, minerals, and natural resources, you will first identify the key oil. In this unit ,you will also study the major natural resources of the world. resource bases of Africa. Hence, the drainage Natural resources are parts of the environment basins of Africa, and its water resources, soils that people can extract and exploit. The and mineral resources, vegetation, and wildlife natural resources provide fundamental life of Africa will be discussed in detail. Unit Outcomes After completing this unit , you will be able to: identify key natural resources of the world; describe the main drainage systems and water resources of Africa; identify the major soil types and mineral resources of the continent of Africa; and assess the main vegetation and wildlife types of Africa. 47  Grade 10 | Geography Main Contents 3.1 OVERVIEW OF MAJOR NATURAL RESOURCES OF THE WORLD 3.2 MAJOR DRAINAGE AND WATER RESOURCES IN AFRICA 3.3 MAIN TYPES OF SOILS AND MINERAL RESOURCES IN AFRICA 3.4 MAJOR VEGETATION AND WILDLIFE OF AFRICA 🌐 Unit Summary 🌐 Review Exercise 3.1 OVERVIEW OF MAJOR NATURAL RESOURCES OF THE WORLD At the end of this section, you will be able to: describe the major natural resources of the world. 🔒 KEY TERMS մ Ecosystem services մ Nonrenewable resources մ Fixed amounts մ Oil մ Freshwater մ Renewable resources մ Natural resources մ Sustainable use Natural resources are parts of the environment that people can extract and exploit (use or manipulate to one’s advantage). People do not make natural resources. They gather natural resources. Natural resources are categorized into two – renewable and nonrenewable resources. Renewable resources can be replenished by natural processes as quickly as humans use them. Examples of renewable resources include sunlight and wind. Whereas nonrenewable resources are natural resources that exist in fixed amounts and can be used up sometime in the future. Examples include fossil fuels like petroleum and coal. 48 Unit Three Natural Resource Base of Africa Activity 3.1 1. Categorize the following resources into renewable and nonrenewable? Wood, water, iron, oil, hydroelectricity, uranium and, the energy of the wind and sun Renewable Nonrenewable Our planet has huge supplies of natural resources that we need to survive. However, our biggest challenge is to use resources without destroying or degrading the environment. Our quality of life and survival depends on our ability to use, rather than abuse the environment. Therefore, sustainable use of resources is very important. Sustainable use refers to the use of resources in a way and at a rate that does not lead to the long-term degradation of the environment, thereby maintaining its potential to meet the needs and aspirations of present and future generations. It is a way that meets the needs of the present and also preserves the resources for future generations. We need to practice the ideas and methods of Natural Resource Management (NRM) for sustainable use of resources. Natural resource management refers to the sustainable utilization of major natural resources such as land, water, air, minerals, forests, fisheries, and wild flora and fauna. Altogether, these resources provide the ecosystem services that provide better quality to human life. 49  Grade 10 | Geography Focus Key Strategies of Sustainable Natural Resource Management Sustainable management of resources involves effective utilization of the following key strategies. Þ Sustainable management of land resources; Þ Maintaining and enhancing water resources; Þ Conserving and recovering biodiversity; Þ Enhancing skills, capacity, and engagement of people; Þ Protecting and enhancing the marine and coastal environment; Þ Delivering high-quality planning that leads to effective action. 3.1.1 The Major Natural Resources of the world The Earth is blessed with different natural resources. However, there are a few selected natural resources that we rely on more than others. Natural resources provide fundamental life support in the form of both consumptive use and public good services. Consumptive use is the use of resources in ways that reduce supply. Examples include mining and logging in a forest. Public good is a good that benefits many people whether or not they have paid for it. Here is a list of natural resources that are extremely important to the existence of life on Earth. I. Water The first natural resource in the above list is water. Arguably, water is the most important of all natural resources. Without water, life would not be able to thrive on the Earth. About 71% of Earth’s surface is water and the oceans hold about 96.5% of that water. While it is technically a renewable resource, the amount of fresh or drinkable water is very small in amount. There is only about 2.5% freshwater from the total amount of water on Earth. Most of the freshwater cannot easily be accessed since it is found underground or in a form of ice and snow in remote areas. 50 Unit Three Natural Resource Base of Africa Activity 3.2 1. Why is water so important? Think about how many things in your daily life require water and list them below. In addition, water in seas and oceans is saline hence, it cannot be directly used for household use and drinking purposes. Of course, there are systems in place to purify non-drinkable water into water safe for consumption through filtration methods. Table 3.1: The Earth’s Water Resources Category Total volume Percent of Percent of (km3) total fresh World ocean 1,338,000,000 96.5 Groundwater (to 2,000 m) 23,400,000 1.7 Predominantly fresh groundwater 10,530,000 0.76 30.1 Soil moisture 16,500 0.001 0.05 Glaciers and permanent snow 24,064,100 1.74 68.7 Antarctica 21,600,000 1.56 61.7 Greenland 2,340,000 0.17 6.68 Arctic Islands 83,500 0.006 0.24 Mountain areas 40,600 0.003 0.12 Ground ice (permafrost) 300,000 0.022 0.86 Lakes 176,400 0.013 Freshwater 91,000 0.007 0.26 Salt water 85,400 0.006 Marshes 11,470 0.0008 0.03 Rivers 2,120 0.0002 0.006 Biological water 1,120 0.0001 0.003 Atmospheric water 12,900 0.001 0.04 Total water 1,385,984,610 100.00 Freshwater 35,029,210 2.5 100.00 51  Grade 10 | Geography In addition, climate change is affecting freshwater by reducing its availability for humans. Due to the changes in weather and increase in ice melt in the poles, precipitation patterns have been changing and reserves of freshwater are quickly disappearing. Activity 3.3 1. From the table above, extract freshwater sources of the world and discuss how scarce the resource is and what need to be done to effectively utilize the existing freshwater. Freshwater sources Measures for effective utilization II. Air Air is another important natural resource which every living thing needs. Air is more than oxygen. Air holds moisture which helps regulate temperature both on the surface and in humans. Meanwhile, oxygen is extremely important because every living thing needs oxygen to survive. Air also includes the atmosphere that is necessary for containing gases needed to keep the temperature of the Earth at a constant and warm enough to support life. Air also regulates the winds which are renewable resources. Windmills or turbines have been created to harness this energy and use it to generate electricity. However, breathable air is becoming more and more polluted. In some areas of the world air pollution is so great that people are forced to wear face masks so they do not breathe in any toxins. Air pollution can lead to many illnesses including cancer. There are many things that you can do to reduce air pollution most importantly by reducing the emission of carbon dioxide. Activity 3.4 1. Give some examples by which you can reduce air pollution. Fr 52 Unit Three Natural Resource Base of Africa III. Soil Soil as a resource, contains many minerals and nutrients that allow plants to grow. Therefore, it is important for the growth of plants and trees. Soil is also an agent of the nitrogen cycle. This is the process of taking nitrogen from the air and converting it into basic ingredients which let plants make their own food. Soil is another natural resource that is threatened by pollution. Soil pollution, caused by overgrazing, landfills, waste materials, fertilizers, pesticides, and other factors is a pressing issue for the land. It can result in low crop production, as well as plant life containing chemicals that are not ideal for human consumption. It can also result in desertification which means the land becomes barren and unable to support plant life. IV. Forest Trees help us in many ways. They produce oxygen, help to deal with the level of carbon dioxide in the atmosphere, and allow people to heat their homes. Moreover, forests are also home to incredible amounts of biodiversity, especially tropical rainforests. About 80% of the world’s species can be found in the tropical rainforests. Moreover, a lot of medicinal drugs are made of plants found in the rainforests. However, forests are being constantly threatened by deforestation. This is unwise destruction of trees by cutting them down. The reason for this deforestation is for lumber, clearing of land for plowing, and other causes such as illegal logging and forest fires, etc. If we are to continue to thrive on this Earth, we have to start treating forests carefully and plant more trees annually. V. Minerals Minerals are very important for industrialization. Rare minerals found within the Earth are the raw material for making electronics like computers and cellphones. Whereas, iron and other minerals are highly used for building and construction purposes. Minerals are either metallic – that can be melted to gain new products or nonmetallic – a combination of minerals that do not produce new products by melting them. Since minerals are nonrenewable resources, wise utilization or sustainable use of the resources is vital. Hence, reuse and recycling of the resources are the most common methods used in the world today. 53  Grade 10 | Geography Activity 3.5 1. What do you think is your role in the sustainable use of natural resources? What can you do to avoid wastage and unwise use? VI. Oil Oil is very essential natural resource. However, this is one of the very scarce non- renewable natural resources. It is the cause of pollution, wars and conflict in many parts of the world. However, it is also what powers our lives. Nearly all of our transportation and manufacturing industrie