THE BRAIN OF GEOGRAPHY OF CJMA
MR. O SOWE
ABOUT A FIFTH OF THE WORLD'S IS MADE UP OF DESERTS, SOME ROCKY, OTHERS STONY AND THE REST
SANDY.
Deserts that are absolutely barren and where nothing grows at all are rare and they are better known
as 'true deserts'.
A desert generally is a barren land with little vegetation and annual rainfall of less than 250mm.
Almost all the hot deserts in the world are confined between latitude 15 to 30°North and South of
the equator.
Nearly all the hot deserts lie in the trade wind belt and are located on the western side of continents
where trade winds are off- shore.
All the hot deserts in the world are washed by the influence of cold currents causing fog instead of
rain in the adjacent coast land of the hot deserts.
Aridity ( dryness) is the key characteristics of the hot deserts.
Such deserts are called Tropical hot deserts or "Trade wind deserts".
A good examples are the great Sahara, Namib, Kalahari, Iranian, Thar deserts etc.
Types of deserts
1. Sandy / Erg desert
2. Rocky desert/ Hamada
3. Stony desert / Reg
4. Badlands
5. Mountain desert
Areas of hot deserts in the world
The Sahara desert( the largest tropical desert in the world located in North Africa).
The Namib and the Kalahari deserts in Southwest Africa.
The Iranian, Arabian and the Thar deserts in the middle- east.
The Atacama desert ( the driest desert in the world located in Chile ).
The Australian desert in Australia
The Mohave deserts in US
Characteristics of hot deserts in the world
located between latitude 15°to 30°North and South of the equator.
Wind action is dominant.
Rainfall is less 250mm per annum.
High rate of evaporation.
Extreme of temperature.
bathed by cold currents.
Low cloud cover.
Absence of thick vegetation.
Low relative humidity.
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THE BRAIN OF GEOGRAPHY OF CJMA
MR. O SOWE
High diurnal range of temperature.
Daily range of temperature is about 17°to 23°C
Reasons for the predominance of wind erosion in arid regions than in humid regions
In humid region their thick vegetation which serve as wind breakers while in arid region there is little
or no vegetation to serve as wind breakers.
In Arid region, the soil is light and can be easily carry by wind compare to humid region.
In humid region, the soil is bind together by moisture while in arid region there is little rainfall to bind
the soil particles.
Processes / Mechanisms of wind erosion in arid regions
1. Deflation
It is the lifting and the blowing away of sand particles by wind.
It results into the lowering of the land.
It leads to the formation of deflation hollow
2.. Abrasion
It is a mechanism of wind erosion.
process whereby sand particles carried by wind blast rock surface and erode them.
Abrasive action of the wind results into the formation of rock pedestal, yardangs, Zeugens and
ventifacts
3. Attrition
Mechanism of wind erosion.
Process whereby sand particles collide with another and break into fine particles as loess.
Mechanisms/ processes of wind transportation
1. Suspension
Movement of the finest sand particles and are suspended into the atmosphere.
Sand particles can travel over thousands of kilometers
2. Saltation
mechanism of wind transportation.
Involves movement of pebbles in series of hope or jump in desert area.
3. Surface creeping ( traction )
mechanism of wind transportation.
processes whereby boulders are rolled along the rock surface
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THE BRAIN OF GEOGRAPHY OF CJMA
MR. O SOWE
Features / landforms produced by erosion in arid regions
Rock pedestal
Yardang.
Zeugen .
Ventifact.
Inselberg.
Deflation hollow.
Mesa and butte
Features/ landforms of. wind deposition
1.Dunes ...two types..Barchan dune and Seif( sword) dune.
2. Loess
Water action in desert
Wadis ( dry Valley).
playa ( temporary salt lake).
Bajada.
Pediments.
Alluvial fan
10 facts about the African continent
1. Africa is the second-largest continent, covering around 30.2 million square kilometers.
2. It is home to over 1.3 billion people, making it the second most populous continent.
3. The Sahara Desert, located in North Africa, is the world's largest hot desert.
4. Africa is known for its diverse ecosystems, including savannas, rainforests, deserts, and mountain ranges.
5. The Nile River, the longest river in the world, flows through northeastern Africa.
6. Africa is rich in mineral resources, including gold, diamonds, and oil.
7. The continent is incredibly linguistically diverse, with over 2,000 languages spoken.
8. Africa has a rich cultural heritage with diverse traditions, art, music, and dance.
9. Mount Kilimanjaro, located in Tanzania, is the highest peak in Africa, standing at 5,895 meters (19,341
feet).
10. The Great Rift Valley, stretching over 7,000 kilometers, is a geological feature that runs through East
Africa, known for its stunning landscapes and unique wildlife.
#kalmax....
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