PHYSICAL FEATURES OF AFRICA

1. Physical features are natural landforms that give the earth shape.

2. Africa is made of the following physical features.

- Lakes and rivers.

- Highland / mountains

- Rift valley

- Plateau

- Coastal plains

- Islands

- Basins

3. Plateau

- A plateau is a raised flat topped piece of land.

- A plateau is a table land.

- A plateau covers the largest part of Africa.

Examples of plateaus in Africa.

- A haggar plateau in Algeria.

- Jos plateau inNigeria

8 - Funta Djalon/Guinea plateau in Guinea

- Bie plateau in Angola

- Nyikka plateau in Kenya

- Yatta plateau in Kenya

Human activities on a plateau.

- Farming

- Mining

- Tourism

- Nomadic pastoralism

- Settlement

8. Reasons why a plateau is good for human settlement.

- It has fertile soils for farming.

- It has pasture for cattle keeping.

- It is easy to construct houses on a plateau.

- There is easy transport on plateau.

9. The Masai live in the Nyikka plateau of East Africa.

10. The word Nyikka means barren\ dry land 11.Pastoral tribes in Africa.

- Fulani - Bahima - The Dodoth -The San.

- Karimajongs - Hausa - Sotho

Highlands and Mountains

-There are three types of mountains in Africa namely; a) Fold mountains b) Volcanic mountains c) Block mountains

Fold Mountains

- Fold mountains are found near the edges of continents.

- They were formed as a result of folding.

- This happened when two forces moving against each other made the young sedimentary rocks to fold upwards.

- The rocks that were very old would break

- The lifted parts are called anticlines and sunken parts are called synclines

- Forces that caused folding were compressional forces.

Examples of fold mountains in Africa:

a)Atlas mountains in Morocco

b)Cape ranges in South Africa

Diagram showing the formation of fold mountains. anticlines synclines

Opposing forces

Land before folds Opposing forces meet Upward movement forms fold mountains

Volcanic Mountains

-Volcanic mountains were formed when molten rocks known as magma forced their way on the surface of the earth.

- They were formed as a result of volcanic activities.

-A Vent is an opening / a feature through which hot molten rocks, water, steam or ash passes to reach the earth’s surface.

-Magma are molten rocks found under the surface of the earth.

10 -Lava is the solidified magma that has cooled and it is found on the earth’s surface.

-Crater is a depression on a volcanic mountain.

- Lava may flow over a large area forming plateaus or cones(domes).

Types of volcanic mountains. a) Active volcanoes. b) Dormant volcanoes. c)Extinct volcanoes.

Active volcanoes:

These are volcanoes that erupt frequently.

Dormant/sleepy volcanoes:

These are volcanoes that are sleeping but are likely to erupt later.

Extinct/dead volcanoes:

These are volcanoes that are old and will not erupt again.

Examples of volcanoes in Africa:

Mountain Country

Active Volcanoes

Mt. Nyiragongo DRC

Mt. Nyamulagira DRC

Mt. Oldonyo Lengai Tanzania

Mt. Cameroon Cameroon

Mt. Mufumbiro Uganda

Dormant Volcanoes

Mt. Longonot Kenya

Mt. Muhavura Uganda

Mt. Moroto Uganda

Extinct Volcanoes

Mt. Elgon Uganda

Mt. Kenya Kenya

Mt. Kilimanjaro Tanzania

Ethiopian highlands Ethiopia

Tibesti mountains Chad

1

Block Mountains

-Block mountains were formed by faulting.

-These are formed when the block between faults is lifted up by forces coming from the centre Of the earth.

-The middle block is forced to sink.

-The raised blocks are known as horst or block mountains.

Examples of Block Mountains in Africa

Mountain Country

Rwenzori Uganda

Usambara Tanzania

Pare Tanzania

Danakil Ethiopia

Great Karas mountains Namibia

Uluguru Tanzania

IMPORTANCE OF MOUNTAINS TO THE PEOPLE LIVING NEAR THEM.

 Mountains provide materials like stones , gravels used for construction.

 They also attract many tourists leading to foreign exchange which is used for investment purposes.

 They are sources of minerals eg iron ore, from Atlas thus promoting mining in Africa.

 They have cool temperatures favourabe for human settlement.

 Highlands led to the formation of orographic rainfall on the wind ward side which supports agriculture.

 Moutains are sources of rivers that provide water for both home use and industrial purposes.

 Rivers originating from mountains are for generating Hydro Electric power for industrial purposes.

 Gentle slopes of the mountains, have fertile soils which support agriculture.

 The lower slopes of mountains encourage the growth of pastures thus promoting livestock farming.

 Mountains provide a beautiful scenery for filming and advertising Africa.

PROBLEMS FACING THE PEOPLE AROUND MOUNTANEOUS AREAS.

 Terrain restricts settlement and other land uses like farming.

 Too much rainfall on the wind ward side resulting into floods and severe soil erosion.

 Mountains makes mechanization very difficult hence low agricultural output.

 Some volcanic mountains are associated with volcanic eruptions which leads to the death of people.

 Temperature inversions in the vallies and low temperature with altitude which also restricts settlement.

SOLUTIONS

 Terracing, contour ploughing afforestation and re afforestation to control soil erosion.

 Carring out irrigation farming on the lee ward side of the mountain.

 Discouraging people from settle ling near the mountains.

 Use of animals like camels and donkeys for transport as an alternative.

 Construction of tunnels through the mountains to shorten the distance.

Exercise.

Draw a sketch map of Africa showing .

1. Atlas 2. Rwenzori 3. Drankensburg

4. Cameroon 5. Ethiopian Highlands 6. Tibesti mountains 7. Adamawa highlands 8. Kenyan Highlands

THE GREAT RIFT VALLEY OF AFRICA

 -The great rift valley of Africa starts from Jordan in the Middle East ends at Beira in Mozambique.

 -The Rift Valley was formed by the process of faulting and by the help of either Tensional or compressional forces.

 -The faults occurred as a result of disturbances in the earth’s crust.

 The highest floor of the rift valley is found around L. Kivu and the lowest is around L. Tanganyika.

 Scarps/escarpments are steep sides of the rift valley.

 Scarps are a problem to people who live in a rift valley because they make it difficult to built roads. The four arms of the great rift valley of Africa: a)The Ethiopian Rift Valley

 -It enters Ethiopia from Red sea.

 -It has L.Abaya and Danakil depression.

b)The Western Rift Valley

 -It runs through Uganda, Rwanda, Burundi and Tanzania.

 -It has lakes like; L. George, L.Albert, L. Edward, L.Kivu and L.Tanganyika. c)The Eastern Rift Valley

 -It runs through Kenya and Tanzania.

 -It has lakes like, Turkana, Nakuru, Natron, Manyara, Magadi, Eyasi, e.t.c. d)The Malawian Rift Valley

 -It runs through Malawi to Mozambique.

 -The lake in this arm is L. Malawi.

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THE DRAINAGE SYSTEM OF AFRICA

Drainage is the way in which rainfall drains away from the land back into lakes, seas and oceans.

The following are the main features of drainage features: i] Drainage basins iii] Lakes ii] Rivers IV] Swamps

RIVERS:

-A river is a mass of flowing water

TERMS USED ON RIVERS AND THEIR DEFINITIONS.

 Tributary is a small river that flows into the main river.

 Distributary is a small river that flows away from the main river.

 Source is where a river starts flowing.

 Mouth is where a river pours its water.

 Confluence is where two or more rivers meet.

 Course is the direction a river moves in.

 Watershed is a line of highland separating two streams which flow into different rivers.

 River bank is a side of a river.

 Estuary is where a river enters its mouth in one wide stream.

 Delta is where a river forms channels before it enters the sea.

Major rivers in Africa:

Rivers Length mouth

R. Nile 6500km Mediterranean sea

Congo 4800km Atlantic Ocean

Niger 4000km Atlantic Ocean

Zambezi 3000km Indian Ocean

18 Orange 2100km Atlantic Ocean

Lipompo 1700km Indian Ocean

Senegal 1700km Atlantic Ocean

Volta 1100km Atlantic Ocean

-Rivers originate from the following features; i ) Lakes ii) Highlands

iii) Melting snow / Glaciers iv) Springs

River Main tributaries Source Nature of mouth

Congo Ubangi, Kasai, Lualaba, L. Tanganyika and Estuary Lukaga, Luapula L. Mweru

Niger Benue Fauta Djallon and Delta Adamawa Mts.

Orange Vaal Drakensberg Mt Estuary

R.Nile Atbara, Blue Nile, L. Victoria Delta White Nile, Kafu, Achwa

Blue Nile L.Tana

Zambezi Kafue, Linyanti Angola plateau Delta

Lipompo Suna, Krocodil High veld Estuary Magalawena

R. Volta Otti, Tano _____ Estuary

MAP SHOWING MAJOR RIVERS OF AFRICA.

R. Tana

R.Rufigi

DRAINAGE LANDFORMS OF AFRICA. Each stage of a rivers development has several features which distinguish it from the others. In the upper or mountain stage a river is very fast and very shallow , except in flood. It has a steep gradient and a very narrow deep valley. These features in the upper stage of rivers are discussed below.

Waterfalls A water fall is a sharp break in the course of a river where water drops through a vertical distance in one fall. At the base of the waterfalls the riverbed is over deepened by the hydraulic force of the falling water forming a plunge pool. It is always formed under such conditions, when the river descends from a relief of high alititude, Presence of a hard rock out crop overlying a softer rock along the rivers profile. Waterfalls are commonly formed in the upper course of a river where lakes fall into in steep mountains. Because of their landscape position, many waterfalls occur over bedrock fed by little

contributing area, so they may be ephemeral and flow only during rainstorms or significant snowmelt. The further downstream, the more perennial a waterfall can be. Waterfalls can have a wide range of widths and depths.

Importance of waterfalls

 Waterfalls purify the water which helps the different aqua life to live through provision of oxygen.  Waterfalls also help in turning waste that runs in the water into nutrients which help plants to grow. This is possible because as they pass over the rocks before flowing into the rivers and lakes, it enables bacterial growth which helps in the decomposition of the wastes.  Water that is got from the different waterfalls does not need to be treated because it is very safe to drink even without boiling.  Waterfalls also add oxygen to the water sources where they flow leading to the water and this helps the fish to breathe properly and live.  Due to the moist nature of the surrounding areas which s caused by the water falls, farmers easily cultivate their land and get good yields of crops which are sold in the different parts of the country to earn a living.  Water from the waterfalls can be used for domestic purposes like washing clothes, utensils and other things at home.  They also helping irrigation of the different crops in the country, due to changing weather that affects farmers, the waterfalls provide water which is used in irrigation purposes.  Fishing can also be done on waterfalls providing food to the people in the country. A GORGE A gorge is a narrow valley with steep, rocky walls located between hills or mountains. It is also a steep sided narrow and deep valley. It forms when waterfalls retreat upstream. The process of formation involves vertical erosion of the river bed by fast running water over the soft rock and underlying between hard rocks.

Importance of a Gorge.

 They are tourist attractions leading to earning of foreign exchange for trade and investments.  They also provide sites for study purposes hence increased knowledge.  They are also important sites for construction of bridges to facilitate transport.  They are also suitable site for the construction of dams to produce hydro-electric power for use in homes and industries.

Some features under middle stage of the river are discussed below.

FLOODPLAIN

A floodplain (or floodplain) is a generally flat area of land next to a river or stream. It stretches from the banks of the river to the outer edges of the valley. It is a depositional feature that is formed by mature river that has reached a graded state of equilibrium. A flood plain develops through meandering of the river. Deposition takes place on the river bed making it shallow and wide. Importance of the flood plains.  They have papyrus swamps which provide materials used in art and craft industries.  Clay can also be obtained from flood plains for pottery and brick making.  Existence of fertile soils due to the depositional materials hence favoring growing of crops.  They also provide sand for construction purposes.

Problems faced in the areas near flood plains.  They are associated with floods that led to loss of lives and property.  They also act as breeding places for carrying vectors like mosquitoes, which cause diseases like malaria.  They easily dry out during dry season resulting into shortage of water for domestic and livestock.  Dense settlement due to the fertile soils which encourage agriculture in the flood plain areas hence leading to land fragmentation.

DELTAS. A delta is a low-lying swampy composed of segments deposited in the mouth of a river. It is an extension of a flood plain. It forms a point where a river enters the lake /ocean. It is also formed when the speed of the river is reduced and deposition of the load increases for the delta to form. The desposited material blocks the river channel .This leads to braiding of the river and formation of the river distributaries near the sea/ocean. The materials deposited in the delta are strengthened by the growth of swampy vegetation.

Importance of Deltas  They encourage the growth of papyrus swamp vegetation which provides materials for art and craft industry.  They act as tourist attraction thus providing the coming in of foreign exchange for trade.  Settlement is encouraged due to the fact that they are flat land areas ie Niger delta and Nile delta.  They act as mining areas due to the presence of petroleum deposits used as source of energy in vehicles.

Economic importance of rivers on the development of Africa.

 They attract tourists for example Zambezi hence providing foreign exchange for trade.

 They help to generate hydroelectricity power used both homes and industries

 They provide fish which act as food hence improving people’s health.

 They provide water for industrial use hence industrialization.

 They provide water for irrigation purposes especially in semi- arid areas

 Some rivers are used for transport hence encouraging trade because they connect different areas.

 They help in the formation of rainfall through evaporation which stabilizes the climate of the continent.

 They are used for recreation.

 They provide materials for craft work hence development of craft industries

 They have alluvial fertile soils which supports the growth of many crops ie around Niger and Niger delta.

Problems faced by people leaving along river valleys in Africa.

 Flooding during the rainy season which leads to loss of lives and destruction of property.  Accidents always occur like drowning hence leading to loss of people’s lives.  Rivers cause high costs of road railway construction due to the need to construct bridges and culverts.  Waterfalls along rivers hinders navigation  Swampy areas near along river banks are breeding grounds for vectors like mosquitoes which cause diseases like malaria.

Problems limitting the use of rivers as water ways in Africa.  Presence of Waterfalls and rapids which leads to death of people hinders navigation of water vessels. Eg on river Nile, R, Volta etc.  They are habitus for dangerous aquatic animals like crocodiles which scare away people from using rivers hence limiting their use.  Remoteness of most rivers in Africa are located in low populated areas  Existence of inland deltas eg on river Senegal making some areas along rivers impassable.  Many rivers have out crops which limits the navigation due accident brought.  Presence of water weeds which leads to accidents through making sailing difficult.

Measures that can be taken to promote inland waterways in Africa.  Constructing of canals in areas where waterfalls exist.  Removing of the floating vegetation to increase navigability along rivers.  Dredging to control silting and thus maintain constant depth of the water.  Construction of locks along long rivers where there is a shallow path.  Improving political stability and interstate co-operation among the nations where the rivers flows through.  Bursting of the rocks beneath the river courses for easy navigation.