Drought

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Drought

  1. 1. Climatic hazards: Drought & Desertification
  2. 2. Starter: Watch the following video clip carefully and identify the issues associated with a lack of rainfall. What is the pattern of freshwater across the world? Why do some places enjoy a surplus while others suffer deficit?
  3. 3. World without water • YouTube clip
  4. 4. Describe the pattern of the distribution of freshwater across the world.
  5. 5. What is a drought? • A drought occurs when there is not enough rainfall to support people or crops • There are various causes, human and natural • Drought is hard to prevent & can cause crop failure, famine, death, fires & desertification • It is a weather hazard that can develop slowly
  6. 6. Deaths as a consequence of drought Of all drought-related disasters from 1975-2000, 98% of deaths occur in just three countries: Ethiopia, Sudan & Mozambique 1975-2000: +560’000 deaths worldwide from drought disasters
  7. 7. Causes of drought Natural / Physical causes: - Weather: increased amount of anticyclone weather (hot + dry) means air holds less moisture so you get less rain - Global warming: weather patterns change (e.g. Sahel is becoming hotter + drier) - Hotter weather = more evaporation than precipitation - El Nino: random weather event that reverses normal weather patterns (e.g. Australia has years of drought + then years of flood) Human causes: - Overpopulation: too many people living in an area using too much water - Overcultivation: planting too many crops which use up too much water - Overextraction: removing too much water from wells so they dry up - Deforestation: cutting down trees which otherwise store water + hold soil together - Politics: fighting over water, or companies being greedy + taking too much water to then sell on
  8. 8. Explore the news • Barcelona drought news • Australia drought • Australia drought 2
  9. 9. Case Studies • LEDC = Ethiopia (Sahel region) 1985-2006 • MEDC = Australia 2005-2008
  10. 10. Ethiopia drought
  11. 11. Ethiopia drought 2006 • Sahel region, drought conditions since 1985 • (Drought of 1984-1985 = 1million deaths) • Causes = natural climatic causes (low precipitation), human causes (deforestation, desertification, overpopulation, overcultivation) • GDP per capita $110, life expectancy 43yrs • 2006 = affected 2.7million people • UNICEF donated $50million to water aid projects • Consequences = famine, migration, disease, 46% of cattle died, debt
  12. 12. Australia drought
  13. 13. Australia drought • 2006 • Extremely low rainfall season (lowest rain since 1900) across southern Australia • River Murray dried up in places • Triggered by ‘El Nino’ weather event – causes excessively low rainfall • Human causes = poor use of water resources • Consequences: 6million sheep died in 2years, temporary migrations, improvements to water resource use, eventual floods!
  14. 14. Causes, effects, case studies, management? • Use the textbook and the photocopies to explore the causes & consequences of drought • Include human & physical causes, the effects & how they are managed • Consider patterns of rainfall & how the land is managed • CASE STUDIES: CAUSES, EFFECTS, RESPONSES
  15. 15. How can drought and desertification be managed?
  16. 16. Watch the slide show from http://www.guardian.co.uk/environment/gallery/2009/may/18/desertifica tion-china?picture=347540416 Mindmap the ways that people are affected by desertification
  17. 17. What is desertification?
  18. 18. How can it be managed? • Afforestation? • Terracing? • Magic stones?
  19. 19. Exam Qs • Describe & explain the causes of drought. [4marks] • What are the patterns associated with droughts? [2marks] • With reference to a case study, describe the effects of and responses to drought. [6marks]

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