Climate Of Africa – Part 1

Climate is the average  weather  condition  observed and recorded for a given region after a long period of time between 30 to 35 years e.g. desert, equatorial, Mediterranean, montanne, etc.

Weather is the  daily  atmospheric  condition observed and recorded  for  a  particular  place   at  a  given  time e.g. sunny, rainy, windy, cloudy, etc.

Africa experiences a variety of climate patterns all the way from the north down south as well as from the west to the east e.g.

• Mediterranean
• Hot desert and semi-desert
• Tropical/ savanna
• Equatorial
• Tropical maritime
• Mountain/montanne
• Warm temperate continental

Sketch map showing climatic patterns

The Climate and Vegetation of Africa

appreciate the dangers of the overuse of the natural vegetation.
appreciate the need to love and care for their local area, community and country
by replanting the vegetation in areas where it has been cleared.
understand the main characteristics of climates and how each affects the
vegetation of the area.
Understand how the traditional farming and way of life was influenced by the climate.

Introduction
You learnt about climate and vegetation in East Africa in Senior 1. Have you ever imagined what the climate and vegetation of other African countries are like? Do you think they have more types of climate and vegetation than what you studied in East Africa? The climate of Africa is determined in the same way that of East Africa is determined.
Can you remember how this is so?
Well, Africa is blessed with a variety of climates and vegetations which you are going to find out. In this chapter you will understand the distribution of climates and vegetation in Africa, the reasons for their distribution and the effects of these climates and vegetation on human development.

Sunlight is Earth’s primary source of energy which is made up of heat and light. Before you study the climates of Africa, you have to look at the earth as a whole and its relation with the sun. After doing tasks in activity 22.1, you will find out more about the relationship between the earth and sun.

Activity 22.1
Understanding the relationship between Earth and Sun
In groups, use knowledge gained from Senior One in chapter five The earth and
its movements and do the following tasks.
1.Brainstorm on the relationship between the Earth and the sun .
2.Draw diagrams to show the relationship between the Earth and the surfs rays.
3. Describe how the Earth-Sun relationship affects;
(a) changes in temperatures.
(b) changes in seasons.
2. What happens when the northern and southern hemispheres are tilted towards the sun?
3. Present your work to the rest of the class through a discussion.

You have learnt that the sun’s movement is apparently caused entirely by the movement of the earth. Our planet earth both spins on its axis and orbits around the sun. This brings about changes in seasons, causes day and night and changes in temperature. All these affect the climate of the African continent.
Tropical, Temperate and Polar regions of the Earth
The sun heats the earth’s surface at different angles. This brings about differences in temperatures leading to the division of the earth into the tropical, temperate and polar regions. After doing tasks in activity 22.2, you will find out the differences between tropical, temperate and polar regions of the Earth.

Understanding the Tropical, Temperate and Polar regions of the earth
In groups, study figure 22.1 and do the tasks that follow.

1.Why is the earth divided into the tropical, temperate and polar regions?
2.Find out whether Africa is also divided into the tropical, temperate and polar regions.
3.Describe the causes of variations in temperatures.
5.Present your findings to the teacher for further guidance.

You have found out that the African continent extends from 350N to 37 os latitude and it mostly lies within the tropics. In the tropical zone, the average temperature in the coldest month is 180C.
In this climate zone, the warmest months average less than 100C. This is another region of Africa. This is called the temperate climate. It is located between the tropic of cancer north west and capricon south west. You can name African countries in this
climate region.
The average temperature of the coldest months in the temperate zone is lower than that of the tropical zones, while the average temperature of the warmest months in the temperate zone is higher than that of the polar zone. e The overhead sun and rising air
As earlier learnt in Senior one the apparent movement of the sun influences rising air, the rainfall pattern and the temperature. Rainfall received in an area also varies with the position of the overhead sun.
After doing tasks in activity 22.3 and revising Senior One activities, you will understand more about the overhead sun and rising air.

Understanding the overhead sun and rising air
Activity 22.3
In groups, study the photograph in figure 22.2 and do the tasks that follow.

1 Describe what you see in figure 22.2.
2 Describe what happens to air when the sun is overhead.
3 Discuss the effects of what you have described in (2)
4 Present your findings to the rest of the class through a discussion.

you have found out that the sun is overhead at the Equator twice a year that is to say March and 23 September. During this period areas around the equator such as; Gabon, Democratic Republic of Congo, Kenya, Uganda, Somalia and Principe and Sao Tome receive heavy rainfall. When the sun is in the Northern hemisphere, the areas receive heavy rainfall while the southern hemisphere remains dry and vice versa.
The Inter-tropical Convergence zones (ITCZ)
Have you ever heard that the Inter-Tropical Convergence Zone (ITCZ) is characterised by convective activity which generates thunderstorms over large areas? After doing tasks in activity 22.4, you are going to explore more about the Inter-Tropical Convergence Zone.
Activity 22.4 Exploring Inter-Tropical Convergence Zone
In groups, study photograph in figure 22.3, Carry out a text book or internet research arid do the tasks that follow.

1.What do you understand by the term inter-tropical convergence zone?
2.Describe how the rising air causes winds to blow from north to south.
Find out;
(a) the position of inter-tropical convergence zone.
(b) the seasonal movements of the inter-tropical convergence zone.
(c) the relationship between the overhead sun, ITCZ , wind movement and
rainfall pattern in Africa.
4.Present your findings to the rest of the class through a discussion.
You have realised that the Inter-Tropical Convergence Zone shifts position throughout the year in relation to apparent movement of the sun. In Africa, it is dominant in SUb-saharan African countries excluding the East African Coast. The Inter-Tropical C Onvergence Zone migrates northwards and is positioned over the tropic of cancer.

How the Inter-Tropical Convergence zone affects different climates in Africa What do you think causes the rainfall to be much at the equator as compared to the higher latitudes? To answer that question, you need to look at the movement of air around the Earth. On a large scale, there are few air masses which shape the rainfall characteristics of tropical Africa. After doing tasks in activity 22.5, you will
understand the effects of the Inter-Tropical Convergence Zone on climate.

Understanding the effects of the Inter-Tropical Convergence Zone on climate
In groups, carry out a text book or internet research and do the tasks that follow.
1 Discuss the effects of the Inter- Tropical Convergence Zone on climate.
2 Find out why places outside the tropics have different kinds of climate not affected by the Inter-Tropical Convergence Zone.
3 Present your findings with the rest of the class through a discussion.

You have realised that the Inter-Tropical Convergence Zone keeps on moving following the position of the Overhead sun. Warm air rises, which leads to convectional rainfall. The convectional rains in most
cases are stormy, so this region is referred to as the thunderstorm zone. The seasonal rainfall pattern in most parts of Africa is caused by the Inter-Tropical Convergence.

Climate of Africa
The climate of Africa has a range of climates such as the equatorial climate, savannah climate, desert climate and Mediterranean climate. Temperate climate is rare across the continent except at very high elevations and along the fringes.
Factors influencing climate in Africa
In Senior One you learnt about factors affecting climate in East Africa. You can discuss them with your neighbour. Similarly, the distribution of climate in Africa, is determined by the same factors. After doing tasks in activity 22.6, you will understand the factors influencing the types of climate in Africa.

Understanding the factors influencing climate in Africa
Activity 22.6
In pairs, carry out a text book or internet research and do the tasks that follow.
1 Discuss the factors influencing climate in Africa.
2 Exchange yourwork with your neighbour and comment on each other’s work.
3 Present your findings to the rest of the class through a discussion
You have found out that, the climate of Africa is influenced by a number Of factors. These include the distance from the sea, ocean currents, direction of prevailing winds and shape of the land.

Major Climate Regions of Africa
climatic regions in Africa have been classified in categories each with sub-climatic
types. This is done depending on the distance of the region from the equator. After
doing tasks in activity 22.7, you will explore more about the climatic regions of Africa.

In groups; use an atlas and the map provided in figure 22.5 and do the tasks that follow.

Copy the map in figure 22.4 into your notebooks and name climatic regions marked A to D
Table 22.1: climatic types and region of location

2 Compare your answers with other groups.
3 Present your work to the teacher for further guidance.
You have found out that climatic regions can be classified using different climatic characteristics. The sun’s rays reach different parts of the earth surface at different angles. This determines the different climatic conditions over those different areas, resulting into different climatic regions.

Characteristics of Climatic Regions of Africa
Every climatic region is determined by the temperature and precipitation of a region over time. After doing tasks in activity 22.8, you will learn more about the characteristics of climatic regions of Africa.

I Draw a suitable graph to represent the climatic conditions for stations C and D.
2 Identify;
(a) the warmest month in each climatic region.
(b) the coldest month in each climatic region.
3 For each station, calculate the:
(b) mean annual rainfall.
(a) mean annual temperature.
4 Describe the characteristics of each climatic region.
5 Describe the factors that lead to such a climatic condition in each climatic region.
6 Giving reasons for your answers, suggest at least two economic activities that can take place in each climatic region.
7 Present your work to the rest of the class through a discussion.

You have found out that savannah climate is usually warm and temperatures range from 200 C to 300 C. Savannas exist in areas where there is a 6 – 8 month wet summer season, and a 4-6 month dry winter season.
Parts of North Africa and Southern Africa as well as the whole Horn of Africa mainly have a hot desert climate, or a hot semi-arid climate for the wetter locations. The biggest part of equatorial Africa is dominated by tropical rainforest. This region receives from 100 to 500 mm of rainfall annually. The Mediterranean
climate of North Africa is characterized by hot dry summers and seasonally restricted rainfall. The western region experiences sub-humid conditions.
Influence of Climate on people’s way of life
Climate affects people’s way of living in different ways. These can be social or economic. First ask yourself, what you do when it rains? Which type of clothes do you put on? Do you drink or eat cold things? Such questions help you understand that climate influences our daily life. After doing tasks in activity
22.9, you will et to know how climate influences peoples’ way of life.

Understanding how climate influences people’s way of life
Activity 22.9
Stud hoto raphs A-D in figure 22.7 and do the tasks that follow.

1In which climatic zones do you think each of these photographs was taken.
2.Explain how climate has influenced people’s ways of life as shown in the photographs.
2.Suggest the likely problems caused by climate to the people living in different climate regions.
4..Share your findings with the rest of the class for further discussion.
Human health has always been influenced by climate. Climate influences the choice of
economic activities we engage in, when and where we do them from. Climate influences
our settlement patterns and the social life styles including the way we eat and dress.
Modern technology versus changes in climate
Humans for the past decades have managed to adapt to the changing climatic conditions. In Africa there is technological development which undermines the effectS of climate so that humans can survive in any condition. After doing tasks in activity 22.10, you will find out how man has adapted to the changing climatic conditions.

t Finding out how people have adapted to the changing climation conditions
Study photographs A and B in figure 22.8 and do the tasks that follow.

1.Describe what you observe from the photographs in figure 22.8
2.How have people adopted to the harsh climates in figure 22.8?
3.In which other ways have people controlled climate change using modern technology and advancement?
4.Present your findings to the rest of the class through a discussion.
You have learnt that a fresh wave of technological innovation is deepening our
understanding of tough environmental challenges and also giving us new ways to solve
them. Even in the absence of rain, people can still cultivate using irrigation farming.

Vegetation of Africa
Did you know that all the trees, bushes and grasses you see around your school or community is vegetation? Vegetation can grow naturally on the earth*s surface or can be planted by people. Natural vegetation develops over years according to the climate and soils in which it grows. After doing tasks in activity 22.11, you will understand the different types of vegetation in Africa.

Activity 22.11
Describing the different types of vegetation in Africa
In groups, Study map in figure 22.9 and photographs A-D, in figure 22.10 and do he tasks that follow.

1(a) Copy the map in figure 22.9 in your note book.
(b) Discuss the factors responsible for the distribution of the types of shown on the map.
2.Identify the types of vegetation shown in each photograph.
Describe the characteristics of each type of vegetation in figure 22.10.
4 Explain how climate has contributed to the existence of each of the vegetation types in figure 22.10.
5 Suggest at least four economic activities that can take place in each of the vegetation types.
6 Using the knowledge obtained in chapter nine, draw a map of East Africa showing its climate and vegetation.
7 Present your work to the teacher for further guidance.
You have learnt that Africa has many types of natural vegetation. For the purpose of
this study, they have been reduced to a few and these are related to major climates of
Africa and they include; equatorial, tropical, Mediterranean and desert vegetation.

You have learnt that Africa has many types of natural vegetation. For the purpose of this study, they have been reduced to a few and these are related to major climates of Africa and they include; equatorial, tropical, Mediterranean and desert vegetation.

Influence of Vegetation on People’s Lives
The vegetation type found in a place can affect people negatively or positively. Many of the economic activities in a place are influenced by the vegetation type found there. Some other places may not be suitable for any economic activity because of the vegetation in that area.
For example, thick forests and swamp vegetation may not be favourable for certain activities. After doing tasks in activity 22.12, you will understand more about how vegetation influences people’s way of life.

Activity 22.12
How vegetation influences people’s way of life
In groups; study photographs A-C in figure 22.11 and do the tasks that follow

I Describe what is taking place in the photographs in figure 22.11.
2 In what other ways does vegetation affect the people’s way of life.
3 Present your work to the rest of the class through a discussion.

People’s influence on natural vegetation
Human activities are contributing to climate change. Changes in climate are causing changes in vegetation patterns around the world. Although people’s activities are influenced by the vegetation cover of an area, they are also responsible for the drastic changes in vegetation for example people cut down trees for wood. This in the long run leads to desertification. After doing tasks in activity 22.13, you will find out how humans have influenced climate change and how they have tried to control these activities.

Exploring the influence of people on natural vegetation
Activity 22.13
In groups, study photographs A-D in figure 22.12 and do the tasks that follow.

1.Describe what is taking place in the photographs in figure 22.12.
2.Identify the photographs showing the negative effects and positive effects of people on vegetation.
3.In which other ways do people destroy not shown in figure 22.12?
4. Which activities do people do to conserve the natural environment?
5. Discuss why it is important to conserve the natural environment?
6.Present your work to the rest of the class through a discussion
You could have found out that the human impact on the environment starts with vegetation, for humankind has possibly had a greater influence on plant life than on any Of the other components of the environment. The changes humans have brought about on vegetation cover include deforestation, bush burning and afforestation.

End of Chapter Summary
In this chapter, you have learnt that;
The relationship between the earth and the sun brings about changes in seasons and causes temperature variations.
The sun heats the earth’s surface in different angles, which causes the difference in temperatures leading to the division of the earth into the tropical, temperate and polar regions.
The sun is overhead at the Equator twice a year that is to say 21st March and 23rd September. During this period areas around the equator receive heavy rainfall when the sun is overhead.
The Inter-Tropical Convergence Zone (ITCZ) is the zone in the tropics where the north-east and south-east trade winds converge.
A The climate of Africa has a range of climates such as the equatorial climate, savannah climate, desert climate and Mediterranean climate.
A Africa has many types of natural vegetation and they include; equatorial, tropical, Mediterranean and desert vegetation.
Many of the economic activities in a place are influenced by its climate and the vegetation type.