Monday, 20 September 2021 12:16

Physical Environment - Class 6 Social Studies Revision Notes

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Physical Environment

  • The physical environment is what is found around us

The Countries of Eastern Africa

  • Eastern africa is the region located in the eastern region of africa.
  • It is made up of eleven independent countries namel
    1. Sudan
    2. Ethiopia
    3. Tanzania
    4. Somalia
    5. South Sudan
    6. Kenya
    7. Uganda
    8. Eritrea
    9. Burundi
    10. Rwanda
    11. Djibouti
  • Sudan is the largest country in eastern africa
  • South Sudan became independent in JULY 2011
  • Djibouti is the smallest country in Eastern Africa
  • Countries without a coastline are called landlocked e.g
    • B - Burundi
    • U - uganda
    • R - rwanda
    • E - ethiopia
    • S – south sudan

Position And Size of The Countries of Eastern Africa

  • Eastern africa lies within latitudes 22 ºN AND 12 ºS and between longitudes 22 ºE and 51 ºE/52 ºE.
    COUNTRY SIZE
    Sudan  1.886 million km²
    Ethiopia  1.104 million km²
    Tanzania  945,087 km²
    Somalia  637,657 km²
    South sudan  644,329 km²

    Kenya

     580,367 km²
    Uganda  241,037 km²
    Eritrea  117,600 km²
    Burundi  27,834 km²
    Rwanda  26,338 km²
    Djibouti  23,200 km²

Latitudes And Longitudes

Latitudes

  • These are imaginary lines that runs from west to east
  • They are also called parallels
  • The main line of latitude is equator at 0º
  • Equator divides the earth into two equal halves called hemisphere.

Characteristics of latitudes

  1. They are parallel
  2. They are of different lengths
  3. They affect climate
  4. They are measured in degrees from the equator
  5. They are 180 lines of latitudes in total

Other important lines of latitudes are;

  1. The tropic of cancer 231/2 ̊ N
  2. The artic circle 66 ½ ̊ N
  3. The tropic of capricorn 231/2 S
  4. The antartic circle 661/2 ̊ S

Longitudes

  • These are imaginary lines that run from north pole to south pole of the earth
  • They are also called meridians or horizontals
  • Main line of longitude is greenwich meridian at 0 ̊
  •  Greenwich meridian is also called prime meridian
  • Prime meridian passes through the greenwich town in london and accra in ghana

Characteristics of longitudes

  1. They run from north to south
  2. They are not parallel
  3. They meet at the polesthey affect time
  4. They are of the same length
  5. They are measured in degrees east por west of prime meridian
  6. They are 360 ̊ lines of longitudes in total.

Use of latitude and longitudes to locate places

  • They are used to give positions of places on the earth’s surface
  • Latitudes locates a place either to the north or south
  • Longitudes locates a place either to the west or east

Map interpretation

  • A map is a representation of the whole or part of the earth’s surface
  • Is a drawing on a flat surface to represent information on the real ground
  • Map interpretation is the process of giving meaning to the features shown on a map
  • To interpret/understand the map, we must study the main elements namely;frame , key, compass, scale and title
  1. Frame - It shows the border line of the area covered by the map
  2. Title - It is also called the heading of a map .It shows the name of the area covered by the map
  3. Key - It contains the symbol and their meaning. It is the main element of a map
  4. Scale - Is the relationship between distances on a map and the actual distances on the ground. Is normally presented as a straight line that is divided into several equal divisions
  5. Compass directions - They are used to tell the direction of an object from another on a map

Interpreting human activities

  • Human activities include
    1. Keeping livestock
    2. Crop farming
    3. Mining
    4. Trade
    5. Forestry
    6. Tourism
    7. Transpotation
    8. Lumbering

      Economic activity Evidence
      Dairy farming Creameries, dairy farms, cattle dip 
      Beef farming Ranches, slaughter houses
      Cash crop Tea, coffee,pyrethrum, sisal, cotton
      Mining Quarry, murram pits, mining company
      Trade Markets, shops,towns, urban centers
      Lumbering Saw mills
      Tourism Game parks/reserves, museum,tourist resorts
      Forestry Forests
      Fishing Fish ponds,fishing villages, fish traps, fish processing
      Transportation Roads,railways,airstrips

 

Interpreting drainage features

  • These include rivers,lakes, oceans, dams, boreholes, swamps
  • Permanent rivers are shown by a continous blue line
  • Seasonal rivers are shown by an identend/broken, blue line.
  • Blue colour is used to show waterbodies

Interpreting settlement

  • These are people living areas
  • They are shown by the use of small black dots
  • Settlement patterns include;
  • Linear settlement along thr roads, railway lines and rivers
  • Nucleted/clustered settlement where people settle at one point in the map

Interpreting administration in the area

  • Administrative features include boundaries for location, divisions, districts, county,constituency and world boundaries.presence of offices e.g.chiefs camp, district officer’s offices, disrict commissioner’s office, county commissioner’s office, county governor’s office.

Physical Features

  • Are things that occur naturally on the earth’s surface
  • They include:
    • Mountains
    • Valleys
    • Plateaus
    • Ocean
    • Seas
    • Gorges
    • Plains
    • Lakes
    • Rivers
    • Swamps
    • Hills, rangers

Relief Physical Features

Mountains

Mountains Location Mountains​ Location
Mt.kenya KENYA Jabel-marra SUDAN
Mt.longonot KENYA  Nubadarfur SUDAN
Mt.marsabit  KENYA Jebel Kissu SUDAN
m.kulal KENYA Ras dashan ETHIOPIA
Menengai crater KENYA  Mt.meru TANZANIA
Mt.margaret KENYA Guna ETHIOPIA
Mt.kilimanjaro TANZANIA Pare mts TANZANIA
Danakil alps ETHIOPIA Ngorongoro crater TANZANIA
Moroto UGANDA Ruwenzori UGANDA
Elgon UGANDA mfumbiro UGANDA

 

Plateaus

  • Plateaus are the largest relief features in Eastern Africa

Country Plateau
KENYA  Uasin gishu, Laikipia, Nyika, Lerochi, Merti, Kinangop
SUDAN  Jabel abyad, Teiga plateau
SOMALIA  Somali
SOMALIA/
ETHIOPIA
ogaden 
 TANZANIA Fipa, Central tanzania, Lesongonoi, makonde


Plains

  • Are low lying areas of almost flat land
Country Plain
TANZANIA Serengeti, maasai
KENYA Lotikipi, awara, kano, Kaputei, loita, Budalangi,kapiti
UGANDA Luwero, Nakasongola, Bilesha
SOMALIA Bilesha, Sarar, Haded

 

Lakes

  • A lake is a water body that is surrounded by land
  • A hollow/depression filled with water
  • We have
    1. Fresh water lakes
    2. Salty water lakes
  • Lake victoria is the largest lake in Eastern Africa and second in the world
  • Lake Tanganyika is the longest lake in Eastern Africa and second deepest in the world
  • Lakes may either be natural or man-made lake.
Country Lake
ETHIOPIA  Chamo, Abaya, Steffanie, Shala
KENYA Turkana, Baringo, Bogoria, Nakuru, Elementaita, Naivasha,Magadi, Jipe, Chala, Kenyatta
UGANDA  Albert, Edward, Bunyonyi, Bisini, George, Kyoga, Kivu, mutanda
RWANDA ruhondo
TANZANIA Natron, Manyara, eyasi, Rukwa, Malawi, tanganyika

 

Rivers

  • A river is a continuous channel of flowing water
  • We have permanent and seasonal rivers
  • River Nile is the longest river in eastern africa
  • Some rivers drain their water into;indian ocean, lake victoria, other lakes, mediterranean sea
Country River
KENYA Turkwel, Kerio, Suguta, Ewaso nyiro N,Ewaso nyiro S, Nzoia, Yala, Nyando, Mara,  Migori, Athi, tana
TANZANIA

Pangani, Wami, Rufiji, Matandu, Malagarasi

SOMALIA Shibeli, juba

 

Swamps

  • A swamp is an area covered with soft mud and some vegetation
  • Vegetation found in swamps is papyrus reeds
Country Swamp
KENYA  Lorian, Lotagipi, Yala
TANZANIA Kilombero, Malagarasi

S.SUDAN

Sudd swamp, Bahr-el-ghazal
UGANDA kyoga

 

Formation of mountains

  • Eastern africa has two types of mountains namely
    • Block mountains
    •  Volcanic mountains

Formation of Block mountains

  • They are also called hurst mountains
  • They were formed through faulting and uplifting process
  • Faults are lines of weakness. Faults were developed as a result of forces acting on the layers of the earth.
  • The forces involved are tensional and compressional forces
  • The middle block was pushed upward by underground forces
  • The underground forces are called upthrust force

Exercise:

Draw the diagram on pg 16 our lives today bk 6

Examples of block mountains

  • D – Danakil alps in ethiopia
  • A – aberdare ranges in kenya
  • M – mau ranges in kenya
  • P – pare mountains in tanzania
  • U – usambara mountains in tanzania
  • R – ruwenzoris mountains in DRC/uganda

Formation of volcanic mountains

  • They are also called volcanoes
  • They are formed through the process of volcanicity/eruption
  • Eruption is when the hot molten material underground is forced out by great pressure
  • The hot molten material is called magma
  • When magma gets to the surface is called lava
  • The magma gets out through a main pipe called vent
  • The opening at the top of a volcanic mountain is called a crater
  • Most mountains in eastern africa are volcaning mountains
  • There are three types of volcanoes namely;
    • Active
    • Dormant
    • Extinct

Examples of volcanic mountains in eastern africa

Country Volcanic Mountain
TANZANIA Kilmanjaro, Meru, Ngorongoro, Lool malsin
RWANDA/DRC nyiragongo
KENYA Elgon, Longonot, Menengai crater, Marsabit, Suswa, Kulal
UGANDA Muhavura, mfumbiro
ETHIOPIA Ras dashan
SUDAN Jabel el mara

 

Formation of the Rift Valley

  • Was formed through the faulting process
  • Formed by either tensional or compressional forces
  • When two parallel faults developed the tensional forces pullsthe rocks apart
  • The middle block between the faults sink
  • The steep sides of a rift valley are called escarpments
  • Features found on the floor of the firt valley include
    • Volcanic mountains
    • Rivers
    • Fault lakes

Exercise:

Draw diagram on pg 18 our lives today bk 6

Formation of Lakes

  • Lakes are huge depressions on the earth’s surface that have filled with water.
  • Lakes were formed in different ways namely
    • Earth processes
    • Volcanic processes
    • Erosion processes
    • River action
    • Human made lakes

Earth Movement Processes

  1. Fault lakes
  2. Downwraping lakes

 

  1. Fault lakes
    • They are also called rift valley lakes
    • They were formed through faulting and sinking process
    • They are usually long and have steep side
    • They are usually deep
    • They are found on the floor of the rift valley
    • They include chala, abaya, chamo, stephanie, turkana, baringo, bogoria, nakuru, elemeitaita, naivasha, magdi, natron, eyasi, manyara, rukwa, malawi, tanganyika, kivu, edward,albert.
  2. Downwarping lakes
    • Are also called depression lakes
    • They are usually shallow
    • Formed when parts of the earth warped downwards and the sorrounding areas warped upwards They include
      • Vi – victoria
      • Ba - bangweull
      • Cha - chad
      • Kyo - kyoga

Volcanic Processes

  1. Crater lakes
  2. Lava-dammed lakes

 

  1. Crater lakes
    • They are formed when water collects in a volcanic crater
    • They include l.chad, jipe, paradise, shala, kalwe, nyungu,ngozi.
  2. Lava-dammed lakes
    • They are formed when lava flow blocks a river valley
    • They include;l.tana, bunyonyi, kivu, mutanda, ruhondo

Erosion process

  • They are formed when a moving ice on high mountains erodes the sides of the mountain thus creating depression. Depressions created are called tarns/corriel/cotque
  • These lakes are also called glacial lakes
  • They include lakes on mountains
Mt Kenya Gallery tarn, Hanging tarn, Teleki tarn, Nanyuki tarn, Michelson tarn  
Ruwenzori mts Speke tarn, Catherine tarn


River Action

  • They are also called deposition lakes or ox-bow lakes
  • They are formed in the old stages of a river
  • At the stage rivers form numerous mmeanders
  • Due to continued erosion and deposition the water cuts off the meander
  • They include;
    • Kanyaboli along r.yala
    • Utange along r.rufiji
    • Bilisia along r.tana
    • Shakababo along r.tana
    • Gambi along r. Tana

Human-made lakes

  • They are also called artificial lakes
  • They are formed when a huge wall is built across rivers
  • Water collects behind the wall forming a big artificial lake
  • They include;
    • Masinga along r.tana
    • Kiambere along r.tana
    • Kamburu along r.tana
    • Gitaru along r.tana
    • Merowe along r.tana
    • Nalubaale along r.tana

Exercise: Test yourself on pg 20-21 our lives today bk 6

Relief Regions of Eastern Africa

  • Relief refers to how high or low an area is from the sea level
  • Relief regions are areas where physical features have been grouped according to their height above sea level
  • astern africa is divided into five relief regions namely.
    • The coastal plains and lowlands
    • The plateaus
    •  The highlands and mountains
    • The rift valley
    • The lake victoria basin

The coastal plains and lowlands

  • Are low-lying strips of land that border
    • The red sea
    • The gulf of aden
    •  The indian ocean
  • They lie between 0 – 200m a.s.l
  • They are narrow toeards the south
  • They are wide towards the north, Widest part in somalia

The plateaus

  • They lie between the coastal plains and the highlands
  • They lie between 300m-2080m a.s.l
  • Are the largest relief regions
  • We have
    • Low lying plateau
    • High lying plateau

Low lying plateaus

  • They lie between 400m-1000m a.s.l.
  • They are immediately after the coastal plains
  • This region is also known as the nyika plateau

High lying plateau

  • They lie between 1000m-2000m a.s.l.
  • Small scattered hills that have resisted erosion are found near inselbergs

Highlands and mountains

  • They generally lie above 2000m a.s.l.
  • Highlands are densely populated due t
    • Fertile soils
    • Favourable climate
  • Mt. Kilimanjaro is the highest mountain at 5895m
  • Examples of highlands are;
    • Western highlands of uganda
    • Ethiopian highlands
    • Kenyan highlands
    • North-eastern highlands of tanzania

The Rift Valley

  • It was formed through faulting and sinking process
  • A valley is a low lying area between two raised grounds
  • Begins in jordan in the middle east and ends at beira in mozambique
  • In eastern africa the valley is divided into;
    • Ethiopian rift valley
    •  Eastern rift valley
    • Western rift valley

Ethiopian rift valley

  • Starts from the red sea and evtends down to l.turkana
  • Runs through ethiopia to kenya

Eastern rift valley

  • Runs from L.Turkana through Kenya down to Tanzania then North of L.Malawi

Western rift valley

  • Runs from north of L.Malawi Tanzania,Uganda,DRC border to L.Albert Lake

Victoria Basin

  • It lies between the eastern and western section of the rift valley.
  • Was formed through downwarping process
  • It lies between 1000m-1500m a.s.l
  • Is the source of river nile
  • Is densely populated due to
    • Fertile soil
    • Favourable climate i.e.adequate rainfall

Exercise on pg 23-24 our lives today bk 6


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Read 1873 times Last modified on Tuesday, 21 September 2021 06:19