Opportunities for Development and Challenges in hot arid and semi-arid areas

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Opportunities for Development and Challenges in
hot arid and semi-arid areas ..and the
impacts
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• Some general ideas
• See pupils book pages 155 - 157

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Agriculture

• Traditional
• Varies from region to region

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Australia

• Aborigines
• Hunter- gatherers

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Middle- East and North -Africa

• Nomadism
• Herding of goats, camels, sheep and cattle
  looking for scarce water and good grazing

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Tuareg of North Africa
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Irrigated agriculture

• Oases such as Douz in Tunisia
• Dates from the multi-purpose date palm
• and olives, figs and oranges in their shade

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On banks of exogenous rivers such as the Nile

• Barley, wheat, beans, rice, cotton,etc grown in
  irrigated areas

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Recent changes

• Construction of Dams
• E.g. Aswan in Egypt
• Has provided all year round water supply,
  formerly seasonal with Nile floods
• Hydroponics practised in oil rich countries
• Desalination plants have provided water for
  agriculture in countries such as Kuwait

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Challenges to agriculture

• Cultivation of marginal land in Sahel has caused
  desertification

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Desertification

• A combination of factors have been responsible
• Human factors (due to population increase)
• over-grazing
• Ploughing up unsuitable lands
• Deforestation for firewood
• Lack of a fallow period
• Climatic factors
• Drought

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Salinisation

• Where high temperatures cause saline waters to be
  drawn to the surface
• Salt is left behind as water evaporates
• Salt crust stops root penetration and stops
  infiltration
• Many crops will not grow
• This can be because of irrigation not properly
  controlled

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Also caused by.

• Salinisation can also be caused when an aquifer
  is over-pumped in coastal areas and salt water
  then pollutes it.

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Further Research

• Read and make notes on TWO examples of
  Agriculture in Arid regions
• E.g. Page 160 Agriculture in the Thar desert
• Geofile 446 Drought and desertification in India
  and Pakistan
• Water management in Tunisia- geog review sept
  2001
• Draa Valley in Morocco, page Raw