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Sahel

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Year 10 Sahel - Water World

Year 10 Sahel - Water World

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  • 1. SAHEL
  • 2.  
  • 3. Characterised by 10 months without rain but the real challenge is the unpredictability of exactly when the rains will come and more particularly how much rain will fall
  • 4. And because of climate change the situation has deteriorated over the past four decades with rainfall totals below the average for the period
  • 5. Dry parched lands with a very low carrying capacity – very little will grow
  • 6. Overgrazing does not help. Massive herds gather wherever there is a little water but the cattle nibble the grass down to the roots so that it dies back and the dry soil is then open to the elements, and soil erosion further damages the land
  • 7. Here there’s evidence of massive soil erosion. Though the rains come infrequently and irregularly when they do arrive they bring torrential storms that wash away the top soil, rendering the land useless for cultivation
  • 8. Typical scene in the long dry season
  • 9. It wont be long before this watering hole completely dries up
  • 10. Having taken note of what you have just seen and read, study page 58 and then answer the following questions
    • Where is the Sahel? Try to mention 3 different points in your answer (3)
    • Can you name at least 3 countries within the Sahel? (3)
    • How would you sum up the Sahel’s climate? - try to mention 3 different characteristics (3)
    • What change in the pattern of the Sahel’s climate occurred after 1970? (1)
    • What might be the cause of the change? (1)
    • Why are floods not uncommon despite low levels of rainfall across the year? (2)
    • Why did people cope better with the climate in the past than they do now? (2)
    • Why do large herds of cattle add to the deterioration of the land? (2)
    • How does the Sahel’s climate compare with that of South East England? (3)
  • 11. Possible responses
    • Runs through Africa (1) west to east (1) and from coast to coast (1). It is on the southern edge of the Sahara Desert (1).
    • Select from: Gambia, Senegal, Mauritania, Mali, Burkina Faso, Benin, Niger, Chad, Sudan, Ethiopia (also northern Nigeria, `northern Cameroon and northern Central African Republic).
    • Long dry season (1), short wet season (1) and unpredictable (1) (never quite sure when rains will come and how much will fall (1)).
    • Decidedly drier (1) in almost all years since 1970 than the 70 years before it.
    • Global climate change caused by human actions (1) (the enhanced greenhouse effect).
    • When the rains come they come in torrential downpours (1) and the water is unable to infiltrate (1) the land because it has become baked hard after the long dry season (1); it is therefore effectively impermeable (1).
    • In the past they understood the limitations of the land (1) and did not stay for long in one area (nomads) (1). Big commercial farms now grow cotton and peanuts for export and this means an end to nomadic existence (1). (1) Also the population is growing rapidly and putting more pressure on limited water resources (1). The local people are forced to use the worst (marginal) land to grow their food (1).
    • Large herds of cattle gather around the few watering holes (1) that exist and nibble the grass down to the roots (1). The bare soil is then exposed to the elements so that when the rains come the top soil is washed away (1), and in the dry season the winds blow away the dusty soil (1).
    • Rainfall amounts are similar across the year (1) but evaporation rates are much greater (1) than in S E England so that little (if any) of the rain is available for crops (1). In the Sahel there is a clear dry and wet season but in S E England the distinction is not so great (1). It is far less hot here than the Sahel (1).