Presentation on theme: "Challenges in hot deserts L.O -To be able to describe the causes and effects of a hot desert challenge. Key Words CausesDeforestation EffectsGrazing Desertification."— Presentation transcript:
Challenges in hot deserts L.O -To be able to describe the causes and effects of a hot desert challenge. Key Words CausesDeforestation EffectsGrazing Desertification
Video http://www.youtube.com/watch?v=zLBYfyp 24Xc&feature=PlayList&p=7E8D6303C82 23522&playnext=1&playnext_from=PL&in dex=41http://www.youtube.com/watch?v=zLBYfyp 24Xc&feature=PlayList&p=7E8D6303C82 23522&playnext=1&playnext_from=PL&in dex=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 Africa Sahel: 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? DESERTIFICATION Increase in population Increase in cattle Deforestation for fire wood Grassland grazed more intensively Roots no longer hold soil togetherRoots may be eaten as well as grass Leaves no longer protect soil from weather Less 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