Relief & Drainage

Relief refers to the surface features of the land above the sea level. Nigeria’s relief can be classified into two main types: lowlands and highlands.   Lowlands Lowlands are areas below 300m above sea level. Notable lowland areas in Nigeria include: The Sokoto Plain (200 – 300m) The Niger – Benue Trough / Valley (100 […]

Relief refers to the surface features of the land above the sea level. Nigeria’s relief can be classified into two main types: lowlands and highlands.

 

Lowlands

Lowlands are areas below 300m above sea level. Notable lowland areas in Nigeria include:

  1. The Sokoto Plain (200 – 300m)
  2. The Niger – Benue Trough / Valley (100 – 300m)
  3. The Chad Basin or Bornu Plain
  4. The Niger Delta (0 – 100)
  5. The Cross River Basin (120 – 180)
  6. The Coastal Plain (0 – 100)
  7. The interior coastal lowland of western Nigeria (100 – 300m)

 

Rocks Associated With Lowlands

  1. The coastal plain: Sedimentary rocks of alluvial deposit.
  2. Niger – Benue Trough: Sedimentary rocks such as limestone, sandstone, and shale.
  3. Sokoto plain: Sedimentary rocks like sand, clay, sandstone, and limestone.
  4. Chad basin: Sedimentary rocks of sand and clay.

Sedimentary rocks are generally associated with lowlands.

 

Importance Of Lowlands

  1. Plains, especially level ones, are suitable for human habitation and settlement.
  2. Some plains are rich sources of minerals like petroleum and coal.
  3. Depositional plains are fertile for agriculture.
  4. Level plains favor communication infrastructure like roads, railways, and airports.
  5. Rivers and plains (basin) provide job opportunities, e.g., fishing.
  6. Rearing of animals is better done on level grounds.
  7. Some plains have rivers that provide water for various purposes.

 

Disadvantages Of Plains

  1. Delta areas may experience flooding, posing environmental hazards.
  2. Some plains may create communication barriers, especially in flooded areas.

 

Highlands

Highlands are areas above 300m above sea level. Highlands in Nigeria include:

  1. The North-Central highlands
  2. The Western highlands
  3. The Eastern highlands
  4. The Eastern scarp land

 

Rocks Associated With Highlands

  1. North-central plateau, Western highland, Mandara Mountain, Shebshi, Alantika, Obudu, and Oban hills are made up of basement complex rocks (a combination of igneous and metamorphic rocks).
  2. Jos plateau is made up of volcanic rocks.
  3. Udi hills are made up of Carboniferous sedimentary rock.

 

Importance Of Highlands

  1. Sources of minerals.
  2. Formation of rainfall, especially orographic rainfall.
  3. Used for defense in times of war.
  4. Serve as windbreaks.
  5. Good sources of rivers.
  6. Rivers provide sites for the construction of Hydro-Electric Power (HEP).
  7. Provide tourist centers.
  8. Used for transhumance.

 

Disadvantages Of Mountains

  1. Barriers to communication.
  2. Promote soil erosion.
  3. Occupy land that could be used for other purposes.
  4. Prevent human habitation.
  5. Mountainous soils are poor in nutrients and not suitable for agriculture.

 

Nigeria: Drainage

Drainage refers to water bodies like rivers and lakes.

 

Rivers In Nigeria

Nigeria is drained by two main rivers: River Niger and River Benue. River Niger is the largest river in Nigeria, originating from the Guinea highlands in Guinea, passing through Mali and Niger Republic to Nigeria, and emptying into the Atlantic Ocean. River Benue has its source from the eastern highlands and joins River Niger at Lokoja.

 

Characteristics Of Nigerian Rivers

  1. The volume changes with seasons.
  2. Presence of rapids and cataracts impedes inland navigation.
  3. Presence of debris like dead leaves, mud, wood, etc.
  4. Short courses with high speed.
  5. Specific direction of flow, with southern rivers flowing north-south and northern rivers flowing radially.
  6. Shallowness.
  7. Color changes with the season.
  8. Seasonality, with most rivers flowing during the rainy season.

 

Importance Of Nigeria Rivers

  1. Medium of transportation.
  2. Generation of Hydro-Electric Power (H.E.P).
  3. Irrigation purposes.
  4. Domestic uses.
  5. Industrial uses.
  6. Provision of employment.
  7. Recreation/Tourism.
  8. Source of food supply (fishes, etc).

 

River Basin

River basin refers to the area generally drained by a river. In Nigeria, there are five major river basins: The Niger basin, The Benue basin, The Chad basin, The Cross River basin, and The South Atlantic basin.

 

Importance Of River Basin

  1. Good site for settlement.
  2. Provision of suitable lands for agricultural purposes.
  3. Medium of communication due to the presence of rivers.
  4. Presence of some mineral deposits.
  5. Provision of water.
  6. Provision of sites for fishing.

 

Lakes In Nigeria

A lake is a body of water surrounded by land. Lakes in Nigeria are grouped into two major types: Man-made or artificial lakes and Natural lakes. Examples include Lake Kainji (man-made) on River Niger and Lake Chad (natural).

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Location, Position And Size Of Nigeria

Map Distances

Map Reading

Components Of Geographic Information System (GIS)

Weather And Climate

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