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