challenges in hot deserts l.o -to be able to describe the causes and effects of a hot desert...
TRANSCRIPT
Challenges in hot deserts
L.O- To be able to describe the causes
and effects of a hot desert challenge.
Key Words
Causes Deforestation
Effects Grazing
Desertification
Video
• http://www.youtube.com/watch?v=zLBYfyp24Xc&feature=PlayList&p=7E8D6303C8223522&playnext=1&playnext_from=PL&index=41
Answer these 5 questions
1)Where does desertification happen?
2)What is desertification?
3)How is it caused?
4)What are the effects?
5)What are the solutions?
Sahelian AfricaSahel: A semiarid region of north-central
Africa south of the Sahara Desert
The Sahel regions are areas which experience
desertification.
Desertification is when a desert gradually spreads, turning land into desert.
Why does the Sahel suffer from desertification?Why does the Sahel suffer from desertification?
DESERTIFICATION
Increase in population Increase in cattle
Deforestation for fire wood Grassland grazed more intensively
Roots no longer hold soil together Roots may be eaten as well as grass
Leaves no longer protect soil from weatherLess vegetation means less protection from weather
Loose top soil blown away by wind
(Soil Erosion)
=
Loose top soil blown away by wind
(Soil Erosion)
=DESERTIFICATION
Since the 1960s the Sahel has been afflicted by prolonged periods of extensive drought.
The above plots are June through October averages of the Sahel rainfall series. The averages are standardized such that the mean and standard deviation of the series are 0 and 1, respectively, for the periods identified in each plot. Sahel rainfall is characterized by year to year and decadal time scale variability, with extended wet periods in 1905-09 and 1950-69, and extended dry periods in 1910-14 and 1970-1997.
Diamond 9 – Causes
Most Important
Least Important
Population Increase
Climate Change
More Cattle
Deforestation
Over Grazing
Top Soil Blown Away
Roots no longer hold soil together
Drought
Ground is exposed to suns heat
Effects
Homework Questions
1. Outline how and why desertification occurs (6 marks).
1. Explain why desertification is a disaster for humans and the natural environment (6 marks).
Plenary
• Key word Pictionary