Natural and Historic Built Environment in Africa - Grade 7 Social Studies Revision Notes

• Maps And Mapwork
  • Position of Africa
  • Countries That Makes Up The Africa Continent
  • Locating Places And Features On A Map Using Latitudes And Longitudes
• Pictures, Plan And Maps
  • Types Of Maps

Maps And Mapwork

A map is a representation of the earth or part of it on a flat surface.

Position of Africa

• Africa lies between latitude 37ºN and 35ºS and on longitude 18ºW and 52ºE.
• Separated by water from all other continent except at the point where it joins Asia.
• Mostly Easterly point is called ras hafun(cape guardafui)
• Mostly westerly is cape verde
• Mostly northerly is cape bon
• Mostly southerly is cape agulhas
• Africa is connected to sinai peninsula by suez canal
• Separated from Spain by strait of gibraltar
• Separated from Arabia by strait of bab el-mandeb

Shape of Africa

The northern half is very wide while the southern is much narrower
At the cape guardafui extends outwards in the shape of a horn therefore the horn of Africa

Size of Africa

Africa is the second largest continent in the world
Has an area of about 30.3 million square kilometres (20% of the total land surface)
It measures 8000 km from north to south and 7400km from east to west
Other continents

1. Asia – 43608000km²
2. Africa – 30335000km²
3. North America – 25349000km²
4. South America – 17611000km²
5. Antarctica – 13340000km²
6. Europe – 10498000km²
7. Australia – 8923000km²

Countries That Makes Up The Africa Continent

Africa has the largest number of countries in the world making o total of 55 countries

1. Algeria 2381741km²
2. Angola 1246700km²
3. Benin 115773km²
4. Botswana 600372km²
5. Burkina faso 274200km²
6. Burundi 28490km²
7. Cameroon 475900km²
8. Cape verde 7275km²
9. Central africa republic 622984km²
10. Chad 1284000km²
11. Comoros 2117km²
12. Congo 34965km²
13. Cόte d’ ivoire 322463km²
14. Djibouti 23310km²
15. DR congo 2345409km²
16. Egypt 1101449km²
17. Equatorial guinea 28051km²
18. Eritrea 124320km²
19. Ethiopia 1221900km²
20. Gabon 267667km²
21. Gambia 11369km²
22. Ghana 238537km²
23. Guinea 245957km²
24. Guinea bisau 36125km²
25. Kenya 582648km²
26. Lesotho 30460km²
27. Liberia 111369km²
28. Libya 1775000km²
29. Madagascar 592900km²
30. Malawi 118484km²
31. Mali 1240192km²
32. Mauritania 1030700km²
33. Mauritius 2040km²
34. Morocco 724730km²
35. Mozambique 802000km²
36. Niger 1267000km²
37. Namibia 824295km²
38. Nigeria 923773km²
39. Rwanda 26338km²
40. Sӑo Tome & principe 964km²
41. Senegal 196192km²
42. Seychelles 453km²
43. Sierra leone 72325km²
44. Somalia 626541km²
45. South africa 1221037km²
46. South sudan 644329km²
47. Sudan 1886068km²
48. Eswatini 17368km²
49. Tanzania 947419km²
50. Togo 56785km²
51. Tunisia 164154km²
52. Uganda 236036km²
53. Western sahara 252120km²
54. Zambia 752618km²
55. Zimbabwe 390759km²

The largest country in Africa is Algeria while the smallest is Seychelles.
Offshore island also form part of Africa;

1. Seychelles
2. Sao Tome and principe
3. Mauritius
4. Comoros
5. Madagascar
6. Cape verde

Locating Places And Features On A Map Using Latitudes And Longitudes

• When giving the position of a place or features we with start with the latitude and then longitude
  Major latitudes and longitudes
• Major longitude is called prime meridian also called Greenwich meridian
• In Africa it passes through:
  
  1. Ghana(Accra)
  2. Algeria
  3. Burkina faso
  4. Mali
• All other longitudes are measured and named from prime meridian up to 180 ̊ on both sides
• Major latitude are 3 passing through Africa

1. Equator 0 ̊ - divides Africa into two parts
   It passes through;
   
   1. Gabon
   2. Congo
   3. DR congo
   4. Uganda
   5. Kenya
   6. Somalia
2. Tropic of cancer 23½ ̊ north of equator
   It passes through;
   1. Western sahara
   2. Mali
   3. Mauritania
   4. Algeria
   5. Libya
   6. Egypt
3. Tropic of capricorn 23½ ̊ south of equator
   It passes through:
   1. Namibia
   2. Botswana
   3. South africa
   4. Mozambique
   5. Madagascar

• Other important lines of latitude are far from africa are:
  
  1. Arctic circle 66½ ̊N
  2. Antarctic circle 66½S

Calculating the time of different places in the world using longitudes

• Rotation of the earth- This is movement of earth on its own axis
• Distance between longitudes is measured in degrees
• There are 360 meridians or longitudes
• One complete rotation is 360 ̊
• The direction of the rotation is from west to east i.e. anticlockwise direction.
• One complete rotation takes 24 hours
• All places found in the east of the Greenwich meridian will see sunrise first and therefore they are one hour ahead of those to the west

Effects of rotation of the earth

1. Differences in time along different longitudes
2. Occurrence of day and night

24hrs = 360 ̊
1hr = ?
360×1 ÷24 =15
Therefore 1hr =15 ̊ or 360 ̊ = (24×60)minutes=1440min
̊= 1440÷360 ×1=4min
I Hr the earth covers 15º and 1º it covers 4 minutes

Calculating time of places found to the east of Greenwich Meridian

Example 1
The time in Accra 0° is 7.00am.calculate time in bermbera 45°E
1hr =15°
? = 45° = 45÷15×1 =3hrs
So 3hrs is equivalent to 45°  then add 3hrs to 7.00am to get 10.00am
Example 2
Suppose the time at GWM is 12 noon what is the local time at Watamu 40°E?
Time gained=40×4=160min=2 hours 40min
Local time at Watamu is 12.00+2.40=14.40-1200=2.40pm.
Example 3
At Dar-es-Salaam 40°E time is 12pm what is the time at Ecuador 40°E?
40°+20°=60°
60×4=240min=4hours
Ecuador is behind in time =12.00-4=8 am.

NB

• When calculating time to the east of Greenwich meridian, we add the time difference to the local time.

Calculating time of places found to the west of Greenwich Meridian

• When calculating time to the west of Greenwich meridian we subtract the time difference to the local time
  Example 1
  A plane leaves off in New York, 74ºW at 7 am local time. What is the local time in Stockholm 18ºE

NB

• If the places are on the same side subtract the degrees to get the difference and add or subtract from the reference time depending on which side the place is.

Pictures, Plan And Maps

Types Of Maps

1. Topographical maps 
   This shows selected natural physical features on a small portion of a country.
2. Atlas map this is a collection of maps in one volume
3. Sketch map maps which are roughly drawn.

A good sketch map should have the following characteristics:

1. Neat and clear
2. Title
3. Frame
4. Key
5. Compass direction

Importance of maps in day to day lives

1. Sketch maps are used to summarise information for easy reference.
2. Used for locating other countries.
3. Used for comparing sizes of countries.
4. For locating climatic regions of different parts of the world.
5. Give information on distribution of geographical phenomena e.g. vegetation on the earth’s surface.
6. Help travellers to find their way.
7. Used to calculate distance of a certain place.
8. Used to locate physical features like landforms.