Hot Deserts Archives - Free ZIMSEC & Cambridge Revision Notes

Wind Action in Deserts: Wind Transport and Deposition

By garikaib|2025-02-12T09:38:25+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Wind transportation methods. Image credit apod.com ZIMSEC O Level Geography Notes: Wind Action in Deserts: Wind Transport

Wind is able to transport (move) sand and dust particles depending on its speed and flow.
The effectiveness of wind erosion and transport depend on a number of factors:
Aeolian […]

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Deflation Hollows

By garikaib|2025-02-12T09:40:09+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Deflation Hollow. Image via Imgkid ZIMSEC O Level Geography Notes: Deflation Hollows

Are also known as closed hollows or blowouts.
These are enclosed depressions caused by wind erosion.
In deserts the wind erodes loose material from flat areas which have, uncemented sediments such as those occurring in […]

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Sand Dunes and Ripples

By garikaib|2025-02-12T09:42:27+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Seif dunes. Image credit 7-themes.com ZIMSEC O Level Geography Notes: Sand Dunes

As soon as wind velocity drops wind deposition occurs.
The heaviest material is deposited first while the finer material and dust is carried further before being dropped.
As a result loess (which consists of fine particles) is sometimes […]

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Yardangs, Zeugens and Rock Pedestals

By garikaib|2025-02-12T08:56:37+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Zeugens. Image credit Revisionworld.com ZIMSEC O Level Geography Notes: Hot Deserts: Yardangs

Zeugens

Pictured in the diagram above.
Zeugens are the ridges in “ridge and furrow” landscapes found in deserts.
These ridge and furrow landscapes sculpted found in hot deserts are a result of wind erosion.
Wind abrasion turns a desert surface […]

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Inselbergs

By garikaib|2025-02-12T09:00:10+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

An inselberg in the Namib Desert. Image credit MediaWiki. ZIMSEC O Level Geography Notes: Hot Deserts: Inselbergs

These are round topped mounds of rock found in deserts as a result of persistant wind erosion over long periods of time.
In some deserts such […]

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Water Action in Deserts

By garikaib|2025-02-12T09:02:10+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Rain falling in a desert. Image credit Snipview.

In most deserts rain does not fall for several years.
When it does it comes in the form of unexpected and infrequent downpours.
Therefore despite the low rainfall totals (about 250mm per annum), water is […]

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Water in Hot Deserts

By garikaib|2025-02-12T09:03:51+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Flash floods in a desert. Image credit Backroadswest.com ZIMSEC O Level Geography Notes: Water in Hot Deserts

Water action in deserts can be divided into three:
freak storms or rain that falls sometimes in semi-arid regions,
dew which plays formed as a result of temperatures […]

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Wadis,Bahadas and the Desert Piedmont zone

By garikaib|2025-02-12T09:05:01+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Alluvial fan/Bajada/Bahada. Image credit MediaWiki ZIMSEC O Level Geography Notes: Wadis and Bahadas

Wadis/Canyons

As already pointed out freak storms occur in deserts characterised by excessive precipitation over short periods of time.
Due to infiltration excess flow and even saturation excess flow there is significant run off in the […]

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Mesa and Butte

By garikaib|2025-02-12T09:06:32+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

Messa (left) and Butte (right). Image credit channingchurch.com ZIMSEC O Level Geography Notes: Mesa and Butte

Mesas and buttes are flat topped uplands with steep sides and often capped by hard resistant rocks.
Mesas and buttes are desert features created primarily by river erosion […]

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Playas

By garikaib|2025-02-12T09:07:39+02:00February 12th, 2025|Hot Deserts, Notes, O Level Geography, Ordinary Level Notes|

A playa. Image credit bergoiata.com ZIMSEC O Level Geography Notes: Playas

These are sometimes known as inland drainage basins.
Due to the fact that there are no permanent drainage patterns in deserts any rain that falls either evaporates or infiltrates into the soil or runs off and […]

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February 2025