Human Causes of Drought

• Deforestation reduces transpiration and reduces the ability for the soil to retain water

  • the soil will dry out -> become parched -> drought
  • therefore the soil will be harder to hydrate again
  • dry soil = more surface run-off, more water lost
  • less transpiration causes less water to be returned to the atmosphere, therefore less precipitation
• Overfarming and overgrazing exposes the soil to wind erosion

  • the soil will have fewer nutrients and minerals
• Excessive irrigation. As more food is needed, more water is taken

  • farmers taking water from the river reduced the river's volume
  • the rivers dry up quicker
  • areas further downstream will receive less water, affecting ecosystems
• Dam building stops water from travelling further downstream

  • natural flow of river is disrupted
  • the ecosystems might dry out
  • less water for animals and civilisations downstream