SCHEME OF WORK AND SECOND TERM NOTE FOR YEAR 10. 2015/2016 ACADEMIC
SESSION
Wk 1 : Oceans
(a) Definition, types, relief and importance (b) salinity of ocean (c) ocean current; types and their
effects on the adjacent coastline
Wkii: The Environment/ Weather and Climate
(a) Meaning, types and importance of the environment (b) definition and differences between weather
and climate (c) elements of weather and climate and their instruments
Wkiii: Weather and Climate Cnt.
(a) Attributes of climate (b) importance of weather (factors affecting weather and climate)
Wkiv: Climate and Nigeria
(a) Climatic regions of the world (b) importance of weather on physical and human activities (c)
Nigeria; location. Position, size and distance
Wk v: Nigeria
(a) Political division (b) physical setting of Nigeria (c) drainage of Nigeria
Wkvi: Nigeria’s Drainage Cnt.
(a) Importance and problems of Nigerian rivers (b) river basin, meaning, types and their uses (c) lakes;
meaning, types, uses and reasons for the shallowness of lake Chad
Wkvii: Nigeria’s Population
(a) Population, meaning, concepts and population distribution (b) population structure (c) population
movement and census
Wkviii: Resources of Nigeria
(a) Mineral resources (b) power resources (c) water resources
Wk ix: Resources of Nigeria Cnt.
(a) Vegetation resources (b) vegetation resources (c) importance of the environment
Wkx: Basic Concepts in Map Reading
(a) Definition, types with examples and uses (b) scale: definition, types and size (c) conversion of
scale
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Wk1: OCEANS
Ocean is the large mass of salt water that occupies a considerable portion of the earth surface. Ocean
basins are large depression on the earth surface, which are filled with a great mass of salt water.
OCEANS OF THE WORLD
There are five major oceans in the world. They include;
 The Pacific Ocean which is the largest ocean,
 The Atlantic Ocean the second largest ocean,
 The Indian Ocean which is the third largest ocean, the Southern or Antarctic Ocean which is the fourth
largest ocean
 The Antarctic ocean
 The Arctic Ocean which is the smallest ocean.
Seas are considerably large bodies of water. They include the Caspian Sea, Mediterranean Sea,
Caribbean Sea, etc. They cover a total of about 25 million Km2 of the earth surface.
S/NO
1.
2.
3.
4.
5.
OCEANS OF
THE
Pacific WORLD
Atlantic
Indian
Arctic
Southern (Antarctic)
AREA IN MILLION KM2
155.557
76.762
68.556
14.056
20.327
Oceanography is the study of oceans. Oceans are studied by oceanographers who find out the chemical
composition of oceans water, its movement, its marine life, landforms, the influence of oceans on the
continents and the importance of oceans to man.
THE OCEAN BASINS AND SEAS OF THE WORLD
There are five main types of ocean in the world: Pacific, Atlantic, Indian, Antarctic and Arctic Ocean
PACIFIC OCEAN:
This is the largest ocean in the world occupying one third of earth surface and is made up of some of the
greatest trenches, some of the trenches extend 5,000fathoms (900metres) deep. Pacific Ocean extends from
the western coast of the Americas to eastern Asia and Australia
ATLANTIC OCEAN:
This is the most important ocean of the world because most of the part which serves some of the most
heavily industrialized nation of the world are along it ridges. It is located between the eastern shore of the
Americas to the western coast of Europe and Africa. It also has an elongated ridge called the mid Atlantic
ridge.
INDIAN OCEAN:
This is the third largest ocean in the world. It stretches more to the southern hemisphere than to the
northern hemisphere. This ocean stretches from the coast of Africa, India and Indo – China and the coast of
Australia, about 60% of its floor form the deep sea plain with a depth ranging from 2000 – 3000fathoms.
ARCTIC OCEAN
It is the smallest ocean in the world and surrounds the whole of the Arctic region. The Northern fringes of
North
THE SEA
The seas of the world cover an area of 25million Sq km and they include the Mediterranean, the Black, the
Dead the Caribbean Sea etc
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THE NATURE OF THE OCEAN FLOOR (OCEAN PROFILE)
The ocean floor is covered with several features that appear similar to those on ground. They include the
continental shelf, continental slope, deep-sea plains, marine ridges and plateatux, ocean deeps, trenches and
ocean islands.
THE CONTINENTAL SHELF:
This is the continuation of the landmass into the ocean. It is the shallowest part of the ocean.
Characteristics:
 It has a shallow and gentle slope with a gradient
of 1/500
 It is rich in planktons
 It contains minerals
 Sunlight is able to penetrate because its shallow
 It has varying depths
 It the continuation of the coastal plain
 It extends under the sea to about 200m
 It forms 7% of the total area of the ocean.
ECONOMIC IMPORTANCE OF CONTINENTAL SHELF
1. They provide good fishing ground.
2. They facilitate the exploration of crude oil in the area.
3. They facilitate the development of natural harbours.
4. They also bring about development of tourist centers. E g Bar beach in Lagos Nigeria.
THE CONTINENTAL SLOPE:
It is a steep slope with depth up to 1801-5401m.It marks the end of continental shelf and links the
continental shelf with the deep-sea plains or ocean floor. It extends to a depth of about 3000m where the deep
sea plain begins. Along the continental slope, mud and red clay can be found.
THE DEEP SEA PLAIN:
This is made up of fairly undulating or level floor of about 2-3km below sea level and covering 2\3 of the
ocean floor. It is also called abyssal plain.
OCEAN RIDGE:
This takes the form of either a ridge or a plateau, which rises from the deep sea plain. Examples include
Mid-Atlantic ridge, South Pacific plateau etc. Some of the ridges and the plateaux rise above the ocean
surface to form oceanic islands example the Falkland and Canary Islands, etc.
OCEAN DEEPS OR TRENCHES:
These are long, narrow and steep-sided depressions that occur at the deep-sea. The deepest trenche in the
world is Marianas Trench in the Pacific Ocean with a depth of about 11,035m.
Features:
 Depth of about 9000m
 They are often close to the continents especially in the pacific.
 They contain deep trenches
 They contain lots of deposits such as oozes, clay
SEA MOUNT:
These are under water mounts that rise from the ocean floor. They could be about 3000m below the ocean
surface.
MARINE DEPOSITS
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These are materials eroded from the earth and deposited at the ocean bed by rivers. They include;
1. Muds: These are ferruginous deposit derived from land and are usually deposited on the
continental shelves.
2. Oozes: These are pelagic deposit derived from the ocean; they consist of the remains of shelly, skeletal
marine micro organism
3. Clay: These occur mainly as red clays on the deepest parts of the ocean basins and are mostly abundant in
the Pacific.
ECONOMIC IMPORTANCE OF OCEANS TO MAN
 Provision of food like fish, prawn, crabs, crayfish
 Provision of employment e.g. Fishermen, Sailors, Ship builders
 Mean of transportation and communication especially for international trade
 For tourism, beach and coast are centres of tourist attraction
 For development of seaport
 They serve as dumping ground for domestic and industrial waste
 The sea bed of most oceans are associated with minerals like petroleum and natural gas, they also provide
sodium chloride (common salt)
OCEAN ISLANDS
These are mountains that are deep seated in the ocean with their peaks extending above the sea level. They
may be formed by folding or volcanic activity. While some are detached from the continental landmasses
others are part of the continents where the coastlands have been partially submerged e.g. Madagascar is part of
the African continental landmass but Hawaii is not attached to any continental land mass. Marine organisms
whose shells are made of calcium, sometimes stick together to form solid land-like masses which are seen
above the ocean surface. These features are known as Coral Reefs.
SALINITY OF THE OCEAN
Salinity of the ocean refers to the degree of saltiness or concentration of salt solution in oceans and
seas. They are often measured in percentage or parts per thousand. The average salinity of the ocean is
about 35grams for every 1000 grams of water. In maps, a line that joins all oceans with the same degree of
salinity is called Isohaline.
FACTORS INFLUENCING OCEAN SALINITY
1. RATE OF EVAPORATION: The higher the rate of evaporation the higher the level of salinity and vice-visa.
The water bodies in the Middle East have high level of salinity in seas within the area while those in the
temperate regions have low salinity. The Dead Sea for instance, has the highest salinity in the world of about
250 parts of salt per 1000 parts of water. The water body with the highest salinity is Lake Van, which has
about 330 parts of salt per 1000 parts of water.
2. AMOUNT OF FRESH WATER ADDED BY PRECIPITATION, STREAMS AND ICE BERGS:
Salinity is lower than average of 35 per thousand in equatorial waters because of the heavy daily
rainfall and high relative humidity, when these oceans becomes diluted with fresh water, their salinity
decreases.
3. THE DEGREE OF WATER MIXING BY CURRENTS: In wholly or partially enclosed seas such as
the Caspian sea where the water does not mix freely with water from other oceans, salinity is high. Where
there is free mixing of high salinity ocean water with low salinity ocean water, the waters are diluted to bring
about variation in their various levels of salinity.
OCEAN CURRENTS
Ocean currents are large masses of ocean surface water circulating in regular patterns around the oceans.
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There are two types of ocean currents, namely Warm and Cold Ocean currents.
THE WARM CURRENTS: They flow from hot equatorial regions towards the cold Polar Regions
and have a relatively high surface temperature; as such they flow on the surface and thus flow on top of cold
current.
THE COLD CURRENTS: They flow from the cold Polar Regions towards the hot equatorial regions and
have relatively low surface temperature. They are much heavier and denser and thus flow beneath the warm
currents.
FACTORS INFLUENCING OCEAN CURRENT
1 PLANETARY WINDS: Planetary winds are the major factor that influences the direction of flow of
ocean currents. This is evident in the north Indian Ocean where the direction of the current changes
completely with the direction of the monsoon winds, which come from northeast in winter and southwest in
summer.
Within the tropics, the trade winds move equatorial waters pole wards and Westwards and warm the
eastern coasts of the continents example the north-east trade winds move the north equatorial current, the
Florida current and the Gulf Stream drift to warm the southern and eastern coast of USA.
2. TEMPERATURE: Water temperatures are not the same at the equator and at the poles. Warm water is
lighter and rises while cold water is heavier and denser, warm equatorial waters move slowly along the surface
polewards while cold denser waters from the poles move slowly along the bottom of the ocean towards the
equator.
3 SALINITY: Generally, water of high salinity is denser than water of low salinity. Hence waters of low
salinity flow on the surface of water of high salinity. Example that of water of opens Atlantic and those of
partially closed Mediterranean Sea.
4 ROTATION OF THE EARTH: Earth‟s rotation deflects freely moving objects including ocean currents to
the right in the northern hemisphere and to the left in the southern hemisphere.
5 THE SHAPE OF THE LANDMASS: The landmass towards which an ocean current moves causes the
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current to be deflected. Current flowing westwards pile up against the coast towards which they flow are
being deflected northwards or southwards. The current may be divided into a number of branches. Example
the south equatorial current divides on reaching Madagascar and the East Africa coast.
DISTRIBUTION OF OCEAN CURRENT ACCORDING TO OCEANS AND THEIR
HEMISPHERE NORTHERN HEMISPHERE:
OCEAN
WARM CURRENT
COLD CURRENT
Atlantic Ocean
North Atlantic Drift current, Florida
current, Gulf Stream current,
cayenne current, Guinea current.
Labrador current, canaries current,
Irminger current
Pacific Ocean
Kuro siwo current, North Pacific
Drift current, Oyashio current.
California current, Okhotsk current.
CURRENT IN THE SOUTHERN HEMISPHERE:
OCEAN
Pacific Ocean
WARM CURRENT
East Australia current, South
pacific Drift current.
COLD CURRENT
Peruvian current.
Atlantic Ocean
South Atlantic drifts current,
Brazilian current.
Falkland current, Benguela current.
Indian Ocean
Mozambique current, N.E
West Australian current, West Wind
Monsoon current, south
Drift.
equatorial current, S.W Monsoon
current, Agulhas
current
EFFECTS OF OCEAN CURRENTS ON THE ADJACENT COASTLANDS
1. On temperature: warm currents rises the temperature of adjacent coastlands while cold currents lowers it.
2. On precipitation: Winds blowing onshore over warm ocean current bring much rainfall to the
adjacent coastlands whereas, cold currents bring dryness.
3. On the formation of fog: fogs are formed when cold and warm currents meet. The cold current cools the
warm moist current which results in condensation to form mist and fog.
4. On storm formation: violent storm is formed when cols and warm current meet because of differences in
their temperature.
WK2 WEATHER AND CLIMATE
Weather refers to the condition of the atmosphere of a particular place at a particular time.
Climate refers to the average weather condition of a place arrived at after taking weather record for a period
between 30-35yrs.
Difference between Weather and Climate
1. Weather refers to daily change while climate refers to average change over a long period of time between
30-35yrs
2. Weather affects only small area while climate affects a whole region
ELEMENTS OF WEATHER AND CLIMATE WITH INSTRUMENTS OF MEASUREMENT
1 Temperature: The degree of hotness or coldness of a place. It is measured in degree centigrade (0 C)
or degree Fahrenheit (0F). Thermometer is the instrument for recording temperature. (0F -32) ÷ 1.8 is used to
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convert from degree Fahrenheit to Centigrade, while (0C X 1.8) + 32 is used to convert from degree
Centigrade to Fahrenheit. Temperature decreases with increasing altitude by 6.5 per 1000m ascent (lapse rate)
2 Rainfall: The water that falls from the atmosphere. It is measured by a Rain-gauge in mm, cm or inches.
3 Pressure: The weight of air at a particular place. It is measured by Barometer in Millibar. Pressure
decreases with increasing altitude.
4 Humidity: The dampness or degree of water vapour in the air. The amount of water vapour that the air
can actually hold at any given time is termed absolute humidity, while the ratio of the amount of water in the
atmosphere to the maximum amount of water vapour that the air can hold is relative humidity. It is measured
with a wet and dry bulb thermometer called Hygrometer in percentage (%).
5 Sunshine: The number of hours during the day which the sun shines. It is also called insolation, the
visible part of the solar energy which is useful to plants and animal. Sunshine duration is measured with sun
dial, while is measure by sun rose.
6 Wind: It refers to air in motion. The direction of wind is measure with a Wind Vane using the
four/eighth cardinal points, while its speed with Anemometer in km/ hour.
7 Cloud: They are particles of water droplets in the upper atmosphere suspended in the air. It reduces
visibility and disperses insolation
NOTE:
 Lines joining places with equal pressure is termed Isobar
 Lines joining places with equal rainfall is termed Isohyets
 Lines joining places with equal temperature is termed Isotherm
 Lines joining places with equal sunshine duration is termed Isohels
 Lines joining places with equal salinity is termed Isohaline
 Lines joining places with equal cloud is termed Isoneph
 Lines joining places with equal elevation is termed Isoline
WK3 : ATTRIBUTE OF CLIMATE
IMPORTANCE OF WEATHER AND CLIMATE
1 There is a strong relationship between weather and culture because it determines what people eat, their
clothes the type of house they build
2 Knowledge of weather and climate is useful in the aviation industry for safety of flights
3 It is useful in the agricultural sector as it determine the types of crop cultivated in the area. Onset of rain
also determines planting time.
4 It affect mental alertness, hot weather is not conducive for mental activity,
5 They determine the health status of an individual. The tropical and hot humid conditions promotes the
easy spread of diseases thus, malaria is common during the raining season
6 It determines the culture of the people like new yam festival, winter sports
7 Knowledge of weather and climate is useful to man against the incidence of rain, flood, typhoon, and
drought etc.
FACTORS THAT AFFECT WEATHER AND CLIMATE
1 Latitude: The position of a place in relation to the equator. Temperature generally decreases from the
Equatorial toward the Polar Regions
2 Altitude: The height of a place above sea level. Temperature decreases with increasing elevation
(Environmental Lapse Rate) at a rate of 6.5 per 1000m ascent or 0.65 per 100m ascent (If the temperature
of a station X at sea level, is 800 (26.70C). What would be the temperature of Y 1300ft (400m) above sea
level where both stations are in the same latitude)
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3 Distance from the Sea (Continentality): Places closer to the sea and equatorial regions experience more
rainfall and longer rainy season than places far inland due to marine influence.
4 Ocean Currents: Warm ocean currents raise the temperature of the adjacent coastlands and cause much
rainfall while the cold currents lower temperature and causes dryness.
5 Slope and Aspect: Sun-facing slopes are warmer than sheltered slopes. Also, slopes facing the direction
of on-shore and moisture laden wind (windward side) experience more rainfall than the leeward side.
6 Cloud Cover: Clouds have a cooling effect during the day and at night, serve as a blanket which traps the
long wave radiation thereby preventing the earth from getting too cool.
SPACE FOR DIAGRAMS
ASSIGNMENT: Explain the following: Harmattan wind (Tropical Continental Air mass), Tropical Monsoon
(Tropical Maritime Air mass), Tropical cyclone.
WK IV CLIMATE AND NIGERIA
Climatic regions are also called Natural Regions. The world is divided into four climatic zones.
 The Hot Climates (Tropical Climates): Found around the equator 300 N & S.
 The Warm Temperate Climates: the region is not really hot but just warm, it is found between 300 – 450 N
& S of the equator.
 The Cool Temperate Climates: A cool zone found between Lat. 450 - 650 N & S of the equator.
 The Cold Climates: found in the polar regions between Lat. 650 - 900 N & S
Space for Diagram
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Climate is the critical factor factor in classifying natural regions. An important element of climate is rainfall.
Climate strong affect vegetation distribution that is why the vegetation belts follow closely after the climatic
regions. Different species of plants adapt to climatic conditions. Such Temperate Forest Tress as Pines, Birch,
Larch, Beach and Oak are absent in the Tropical Forest Rather such trees as Iroko, Mahogany, Obeche, are
present.
The amount and distribution of rainfall is the most important factor affecting vegetation in each zone.
MAJOR TYPE
SUB-TYPES
a) Equatorial Climate
HOT CLIMATES
b) Tropical Continental (Sudan) Climate
c) Tropical Monsoon Climate
d) Tropical (Hot) Desert Climate
a)
Warm Temperate Climate Western Margin (Mediterranean type)
WARM TEMPERATES
b) Warm Temperate Climate Eastern Margin (China type)
CLIMATES
c) Warm Temperate Climate interior climate (steppe)
COOL TEMPERATE CLIMATES a) Cool Temperate Climate Western Margin (British type)
b) Cool Temperate Climate Eastern Margin (Laurentian type)
c) Cool Temperate Climate interior climate (Sub- Arctic/ Siberia
type)
a) Tundra
COLD CLIMATE
b) Cold Desert/ Ice cap
Nigeria: The most populous country in West Africa with independence in 1960 and became a republic in
1963. Location: Nigeria is located between Lat. 40 – 140 North of the Equator and Long. 30- 150 East of the
Greenwich Meridian.
Position: Nigeria is surrounded by francophone countries except at the south where she shares boundary with
the Atlantic Ocean. She shares boundary at the North with Niger republic, at the South with the Atlantic
Ocean, the East with Cameroon Republic and the West with Benin Republic
Size: Nigeria has a landmass/area of 923, 700 sq km. it the fourth largest country in Africa, occupies 1/7th of
the mainland of West Africa, 4 times larger than Ghana, 13 times the size of Sierra Leone, 86 times the size
of Gambia
Distance: The distance of Nigeria from the north to the south is 1,100 km and from east to west is 1,300 km.
the latitudinal extent of Nigeria is 100 and the longitudinal extent is 120
SPACE FOR DIAGRAM
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WK V NIGERIA
Political Division: Presently, Nigeria has 36 states and the Federal Capital Territory Abuja.
Assignment: Draw an outline map of Nigeria showing the 36 states and capital with Abuja
Physical Setting of Nigeria: This refers to the relief of Nigeria which means the surface features of places
above sea level in Nigeria.
The relief of Nigeria is divided into two, namely,
 The high lands regions (300- 900m ASL are found in the areas of basement complex rocks in the southwestern and north central region, while the highest region are on the Jos Plateau and the Eastern
boarderlands)
 The low land regions (below 300m ASL)
The high lands regions. There are four high land regions in Nigeria namely;
 The North Central Highland
 The Eastern Highland
 The Western Upland
 The Eastern Scarpland
THE NORTH CENTRAL HIGHLAND: It is made up of the plain of Hausaland (750m) and the Jos
plateau (1500-1800m). The following rivers take their source from here: River, Kaduna, Sokoto, Hadeija. The
rainfall here is single maximum
THE WESTERN UPLAND: Found to the West of River Niger around Osun, Oyo, Ondo, Edo, Kwara, Ekiti
states. The elevation is between 300-600m ASL. Prominent hills here are; Idanre (950m), Apata hills (400700m ASL), Kukuruku hills, Epeme hill (350-600m ASL) and Amoye inselgerg. Rivers Osun,Ogun,Osse
take their source from this place.
THE EASTERN SCARPLAND: Found to the South of River Benue around Eungu and Nsukka (UdiNsukka platuea and Orlu uplands). The everage elevation is between 300-400m ASL. The area is made up of
carboniferous sedimentary rocks. Rivers Anambra, Imo and Cross river take their source from here.
THE NORTH-EASTERN HIGHLANDS: Found to the North and South of River Benue at the eastern
boader between Nigeria and Cameroon. They include; Mandara Mt (1200-1500m), Bui Platuea (800-1000m),
Adamawa Mt. (1800-2400m), Atlantica and Shebshi hills (1600-2000m), Obudu and Oban hills (1200m).
Rivers Yedseram, Gana and Ngoda take their source from here.
ECONOMIC IMPORTANCE OF HIGHLANDS TO THE ECONOMY OF NIGERIA
1. Sources of minerals resources
2. Good site for communication ,mast
3. Sources of rivers
4. Hydrological centres
5. Act as wind breaker
6. They cause orographic rainfall at the windward side
7. For agricultural actitivities eg. Transhumane, Apple growing
8. Tourist centres
9. They moderate the climate of the area
10. Sources of valuable building material eg, Granite.
THE LOWLAND REGIONS OF NIGERIA INCLUDE;
 The Sokoto Plain (100-300m): Made up of sedimentary rocks with single maximum rainfall at the North9
westen corner of Nigeria.
 The Chad Basin: At the extreme North-eastern part of Nigeria around Lake Chad, Borno and Yobe state
with elevation of 45-60m ASL. Rivers Yedseram, Hadeija Yobe and Komadugu Gana drain the area into
Lake Chad an inland drainage basin.
 The Niger- Benue Trough: Wrapping around the North Central Plateau and following the valley of River
Niger and Benue with elevation between 100-150M ASL. The area has alluvial soil. Sugar cane is cultivated
here.
 The Southern Coastlands: found around Lagos, Ondo, and also in Akwa-Ibom States with elevation
between 20-50m ASL. The rock here is sedimentary with double maxima rainfall.
 The Cross-River plains: it a low lying region between Udi hills and the eastern boarderlands. It is a vast
area measuring 100km East-West and 300km North-South with an Average Elevation of 120-18-m ASL.
SPACE FOR DIAGRAM
ASSIGNMENT in your Geo. Notebook: Write on the geographical regions of Nigeria under the following
heading;
People and population, resources and economic activities, transportation, problems and solutions.
DRAINAGE OF NIGERIA.
This refers to the surface rivers and lakes in Nigeria. All the rivers in Nigeria take their source from one
highlands.
The major rivers in Nigeria are River Niger and Benue. Other rivers include, River Sokoto, Kaduna, Imo,
Anambra, Osse, Ogun, Osun. Gongola, Katsina-Ala, Hadeija, Gana, Yobe.
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3
4
5
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CHARACTERISTICS OF NIGERIAN RIVERS.
They are short flowing rivers with high speed
Presence of rapids and cataracts
They contain water weeds
They are shallow and full of silt
Seasonal fluctuation in the volume of river water
Seasonal change in the colour of the river ware
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They all have specific direction of flow from North to South
They are seasonal in flowing
WK VI NIGERIAN’S DRAINAGE
IMPORTANCE OF NIGERIAN RIVERS
1 For generating Hydro-electricity eg Kainji Dam
2 For irrigation agriculture in areas with low rainfall and during dry season
3 For transportation of people and goods in riverine communities
4 For tourism and entertainment eg. River Sokoto Argungu Fishing Festival in Kebbi State.
5 Provide water for domestic use eg. Bathing, washing clothes,
6 Provide water for industrial use especially in beverage industries, construction companies etc.
7 Provide food such as fish, Cray fish, crabs etc. which are source of protein
8 Source of livelihood eg canoe carving, fishing
PROBLEMS OF NIGERIAN RIVERS.
1 Presence of water weeds eg water hyacinth
2 Presence of rapids and cataracts obstruct the flow of water
3 The seasonal change in the volume of water limit their use for transportation and irrigation
4 The silting up of the mouth of the rivers makes entering of large ships difficult
5 They are shallow river because of the silt nature
6 They are narrow rivers
7 They are often polluted by refuse from households and industries
SPACE FOR DIAGRAM
RIVER BASINS
Meaning: This refers to an area generally drained by a river and its tributaries.
Major River Basins in Nigeria
1 Niger Basin
2 Benue Basin
3 Chad Basin
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4 Cross-river Basin
5 The South Atlantic Basin
The river in this basin are grouped into three categories
1. Long flowing rivers eg River Niger and Benue
2. Short flowing rivers eg. River Osun, Ogun, Osse, Imo etc
3. Rivers in basin of inland drainage. Eg Rivers Yedseram, Yobe, Gana and Hadeija.
Niger Basin : The area is drained by River Niger which takes it source from the Foulta D jallon highland in
Guinea and enters into Nigeria through the western corner. It is the longest river in Nigeria with a length of
about1200km. It has four major tributaries; River Benue, Kaduna, Sokoto, and Anambra.
Benue Basin: The area is drained by River Benue which takes it source from the Cameroon highlands and
flow into Nigeria at the eastern corner. It is the major tributary of River Niger. It joins River Niger at Lokoja
where it forms a Confluence. It tributaries are River Katsina-Ala, Gongola and Danga.
Chad Basin: This basin has five principal rivers that drain into Lake Chad: River Hadeija, Yobe, Yedseram,
Ngaoda and Gana. It is an inland drainage basin because these rivers flow into it and don’t flow out. It covers
an area of about 10,000-13,000 sqkm with an average depth of 2.5m. it a is a structural natural depression.
The South Atlantic Drainage Basin: The area is drained by rivers Ogun, Osun, Imo, Otamiri.
The Cross-River Basin: The basin lies east of the Udi Hills in southeastern Nigeria and drained by cross
river with its tributaries. It enters the Atlantic Ocean through an estuary just below Calabar.
LAKE: A body of water surrounded by land.
Types:
1 Natural Lake: Natural depression surrounded by land, eg Lake Chad
2 Artificial Lake: Depression made by man for several purposes. Eg kainji Dam, Jebba Dam.
REASONS FOR THE SHALLOWNESS OF LAKE CHAD
1 The location of the lake: The Lake is located in the Sahara desert where evaporation is high leading to
low volume of water.
2 Nature of the rivers flowing into the lake: most of the rivers flowing into it have lost their water to
evaporation and infiltration before reaching it because they flow through the semi-desert
3 It is suspected that the lake has an underground leakage into a nearby Oasis
4 The sag which the lake occupies is itself shallow.
NOTE: The uses of lake is synonymous with the uses of rivers
WK VII POPULATION OF NIGERIA
Population refers to the total number of people living together in a defined geographical territory.
Population concepts
 Population size: the number of people in a place
 Population quality: refers to the level of education, health and technological development of the
population
 Population structure: the age and sex composition of the population
 Over-Population: A situation where the human population is considered too large compared to the
available resources for the people to enjoy the highest standard of living. Thus, there is population than its
physical human resources can support with adequate living standard.
 Optimum Population: a situation where the number of people can be supported by the available resources
so as to achieve the highest standard of living
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
Under-Population: a situation where the available resources exceed the number of human such that there
is abundance of resources. Thus with the highest living standard
 Population Density: Number of people per unit area of land expressed as total population/ total land area
in km2.
Types of Density
Crude density is calculated using total land area irrespective of the fact that some parts are uninhabited
Ecological density is calculated using only the portion of land inhabited
NOTE: Calculate the population density if Nigeria in your notebook.
Population distribution in Nigeria
The population of Nigeria is unevenly distributed; some places are densely, moderately while others are
sparsely populated
Densely Populated Areas (Areas with 200 persons per sq km2)
 The south-western part of the country (the Yoruba land)
 The south-eastern part of Nigeria (ibo land)
 The area around Kano region
Reasons for high population density
 Presence of industries
 Employment opportunities
 Presence of industries and commercial activities
 Presence of mineral resources
Why are these places densely populated? Write it in your notebook
Moderately populated area (Areas with density between 50-200 persons per sq km2)
 The jos plateau
 The bui plateau
 The sokoto region
 Edo-delta region with exception of the southern swampy region
 The guinea savanna zone in Kogi and Kwara States
Sparsely populated regions (Areas with density between 20-50 persons per sq km2)
 The sahelian region in the north-east
 The swampy region of the niger delta and coastlands
 The middle belt region
 The eastern boarderlands
Reasons for low population density
 Absence of mineral resources and industries
 Problems of tse-tse fly and Black flies associated with sleeping sickness
 Problem of trans-Sahara trade
 Absence of social amenities
What factors are responsible for their distribution?
Population Structure: The age and sex composition of the population. In Nigeria the structure is a
pyramid with two parameters with the male on the left and the female on the right. The age composition
determines the dependency ratio. Population structure determines the following: The material need of the
people and the pattern of development of resources, industries and commerce, the labour force is influenced
by the age and sex composition of the population, the healthcare requirements is determined b the age of the
population.
SPACE FOR DIAGRAM
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POPULATION MOVEMENT
Rural-urban movement: from village to city centre in search of job or good living standard eg from Ankpa
to Abuja
Urban to rural movement: From the city to the village eg on retirement
Rural-rural movement: From one village to another for agriculture
Urban-urban movement: From one city centre to another eg job transfer
Seasonal movement: Movement at a particular season eg raining season for agriculture, summer holiday
International movement: Movement from one country to another eg from Nigeria to U.S.A
Population Census: Also called Enumeration is the per head count of people living in a defined geographical
territory irrespective of the age, sex, racial and religious background. Enumerators are those involved in the
work.
WK VIII BASIC CONCEPTS IN MAP
Definition: A map is a pictorial representation of the earth or part of the earth on a flat piece of material such
as paper, cloths, board or wall. Maps are drawn by cartographers to scale.
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TYPES
Atlas Map: A map that covers a country, a continent or the whole world. It is a small scale map that covers a
large land size.
Topographical Maps: they use contour lines to show elevation or shape of an area. Lines that are close
together show a steep terrain, while those with lines wide apart show a flat or gentle terrain. It’s usually a
large scale map.
Statistical Maps: A map where climatic and statistical data are represented in charts or graph.
Climate Maps: Show information about climate and precipitation
Economic or Resource Map: They show the location of natural resources or economic activities in a country
or region.
Physical Maps: They illustrate the physical features of an area eg Mountains, Valley, Rivers using colours.
Yellow colour is used to show highlands, green for lower elevations, blue for rivers.
Political Maps: They depict national, state and local government boundaries with major capital cities. A
capital city is usually shown with a star within a circle.
Road Maps: they show major, secondary, minor roads and high way, airports, railways.
Uses of map
They are used to plan a trip to both known and unknown places
They are use to locate useful features/ treasures in an area.
SCALE: The ratio between measurement on land and the actual distance on the ground (the real world). All
maps are drawn to scale because there is no paper of flat piece of material as large as any part of the earth. In
drawing a scale, there should be a balance between the scale and the amount of information on the ground.
Types of Scale
 Large scale: It covers a small area and gives detail information about the features in the area. They
show schools, settlements, roads, villages.
 Small scale: It covers a large area with little information about the features in the area. They show
maps of countries, continents and the world.
Kinds of scale
1 Statement Scale: Words are used to describe the ratio between the distance on the map and the actual
distance on ground. Eg. 1cm rep 2km. 2cm to 1km. The first part of the scale rep distance on the map
while the other rep distance on ground.
2 Representative Fraction/ Ratio Scale: Fractions or ratio are used to show the distance between
distance on map and the actual distance on ground. Eg 1/ 50,000 or 1: 50,000, 1/200,000 or 1: 200,000
3 Linear Scale: The use of line to represent a scale. It is divided into two section, primary and
secondary division. The division on the line rep distance on the map while the difference between the
figure in km or meter rep ground distance.
CONVERSION OF SCALE:
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