Life in the Sahara and the Sahel: Adapting to a Desert Region - PowerPoint PPT Presentation

Loading...

PPT – Life in the Sahara and the Sahel: Adapting to a Desert Region PowerPoint presentation | free to download - id: 3d83e9-Mzg0Y



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Life in the Sahara and the Sahel: Adapting to a Desert Region

Description:

Life in the Sahara and the Sahel: Adapting to a Desert Region Chapter 20 I. Geoterms A. Desertification: the process by which land becomes more and more dry until it ... – PowerPoint PPT presentation

Number of Views:718
Avg rating:5.0/5.0
Slides: 46
Provided by: gohs1Tvu5
Learn more at: http://gohs1.tvusd.k12.ca.us
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Life in the Sahara and the Sahel: Adapting to a Desert Region


1
Life in the Sahara and the Sahel Adapting to a
Desert Region
  • Chapter 20

2
I. Geoterms
  • A. Desertification the process by which land
    becomes more and more dry until it turns into
    desert. This may be caused by climate change,
    human activities, or both.
  • B. Drought an unusually long period in which
    little or no rain falls
  • C. Marginal Land land that is not well suited
    for growing crops
  • D. Pastoral Nomads groups of herders who move
    with their animals from place to place in search
    of pasture and water.

3
II. The Geographic Setting
  • A. The Worlds Largest Desert
  • 1. 3.5 million square miles (size of USA)
  • 2. Daytime temperature is 136F.
  • 3. About 6,000 years ago climate started to
    change creating a desert
  • 4. Trade winds from the north eliminated any
    moisture
  • 5. Most plants, animals, people that live here,
    live near oases.

4
Worlds Largest Desert
5
  • B. The Sahel On the Saharas Edge
  • 1. Sahel is on the southern edge of the Sahara
  • 2. Sahel receives more rain than the Sahara but
    often has long droughts
  • 3. Sahel is marginal land which is not good for
    farming (subsistence farming)
  • 4. People living here are pastoral nomads (people
    moving from place to place looking for water and
    grazing land for their animals
  • 5. Desertification is causing the Sahara to expand

6
Sahel
7
Nomadic Herdsmen in the Sahel
8
III. The Desert Environment
  • A. The Desert Landscape More Than Just Sand
  • 1. Three landforms
  • A. Ergs great seas of sand with tall sand dunes
    over 400 feet high
  • B. Regs gravel-covered plains
  • C. Hammadas high rock-covered flatlands
  • D. Nile and Niger rivers with sources in
    mountains beyond the desert
  • E. Wadis dry riverbeds that can turn into raging
    rivers after a rain and then quickly dry up again

9
Ergs and Regs
10
Hammadas
11
Wadi in the Sahara
12
  • B. The Harsh Desert Climate
  • 1. Temperatures daytime 100 degrees, night time
    may drop below freezing
  • 2. Sandstorms can reduce visibility to nothing
  • 3. Rain is unpredictable with flash floods
    occurring
  • 4. Plants adapt to climate
  • A. deep roots to anchor it and get moisture
  • B. Small waxy leaves that retain moisture

13
Sandstorm in Sahara
14
Plants of the Sahara
15
  • Transparency 20B
  • Answer questions (20.3) page 150

16
IV. Adaptations to Life in the Desert
  • A. The Wandering Tuareg
  • 1. Nomadic Tuareg raise camels, goats, cattle, or
    sheep
  • 2. They move about in search of grazing areas
    (caravans)
  • 3. Known as Blue Men of the Desert because they
    wear long blue robes that project them from sun
    and sand

17
Nomadic Tuaregs
18
  • 4. Live in family groups of lt100 people
  • 5. Can pack all possessions on just one camel
  • 6. They trade (meat, cheese, milk) at oases
  • 7. They often travel at night by reading the
    stars and it is cooler

19
Tuareg Family
20
  • B. Technology Makes Life Easier
  • 1. Use lightweight plastic and metal containers
  • 2. Some use satellite phones to talk to customers
  • 3. Drilling machines create new oases by drilling
    through rock to underground water sources
  • 4. Trucks and planes being used to transport
    people and goods

21
Modern Technology in the Sahara
22
  • Answer question (20.4) on page 150

23
V. The Oasis environment
  • A. Islands of Water Surrounded by Desert
  • 1. Natural oasis springs bubble up to surface
    from underground or low spots where land dips to
    underground stream
  • 2. Human made hand dug wells or machine drilled

24
Rain Catchers vs Drilling
25
  • B. Large and Small Centers of Life
  • 1. Sahara has about 90 large oases that can
    support a village and many small ones that can
    only support a family
  • 2. Many different plants and animals
  • A. Acacia and Baobab trees and shrubs
  • B. Gazelles, butterflies, and insects
  • C. Date Palms (most important) for fruit,
    building materials, rope, and animal feed

26
Oases
27
  • Transparency 20C
  • Answer questions (20.5) on page 151

28
VI. Adaptations to Life in the Oases
  • A. The Traditional Ways of Oasis Settlers
  • 1. Trading and farming is the major economic
    activity of an oasis
  • 2. Most people are subsistence farmers
  • 3. Some grow cash crops (dates, wheat, barley,
    and vegetables)
  • 4. People stop here to trade and get water
  • 5. Homes made of mud brick to keep out heat

29
Farming an Oases
30
People Living on an Oases
31
  • 6. Most work is done in cooler part of the day
  • 7. Windbreaks planted to protect from wind and
    sand
  • B. Water Problems Limit the Growth of Oasis Towns
  • 1. As oases grow, water must be brought in by
    truck
  • 2. If too much water is used for either people or
    crops, it will run out.

32
Water at an Oases
33
  • Answer question 20.6 on page 151.

34
VII. The Sahel Environment
  • A. A Landscape Threatened by Drought and
    Desertification
  • 1. Sahels vegetation is mix of acacia trees,
    baobab trees and small shrubs
  • A. North of this is desert lack of rain
  • B. South is greater variety of plants due to more
    rain

35
Drought in the Sahel
36
  • 2. Droughts lasting gtsix years
  • 3. Desertification
  • A. Winds take away soil
  • B. Sahara desert is expanding

37
  • B. Over grazing by cattle is a major cause of
    desertification in the Sahel (causes destruction
    of cover plants, allowing wind or water to erode
    the soil)

38
  • Transparency 20D
  • Answer questions 20.7 on page 151

39
VIII. Adaptations to Life in the Sahel
  • A. Plant crops that require little water (grains
    like millet and sorghum)
  • B. Shifting Agriculture farmers plant on field
    for 1-2 years and then change fields
  • C. Human Causes of Desertification
  • 1. Farmers plant crops (peanuts) that deplete
    soil faster, then soil blows away
  • 2. Herders expanding herds and animals overgraze,
    turning land into desert
  • 3. Deforestation people cutting down trees so
    erosion occurs

40
Millet
41
(No Transcript)
42
  • D. Agencies trying to correct this problem
  • 1. Get people to burn coal rather than trees
  • 2. Plant windbreaks
  • 3. Conserve water
  • 4. Improved farming methods

43
Improving Farming Methods
44
IX. Globally Desertification Happening Around
Other Deserts of the World
  • Transparency 20E
  • A. China
  • B. Baja California
  • C. Peru
  • D. Kazakhstan
  • E. Australia

45
X. Global Connections
  • A. Are the worlds deserts growing or shrinking?
  • B. What human activities contribute to
    desertification?
  • C. How might people adapt to living in areas
    threatened by desertification?
About PowerShow.com