human factors effecting hydrological cycle

• irrigation -

  • taking water from store reduces river flow = lower water table and increased evaporation
• afforestation -

  • trees = increased interception = less surface water
  • roots = infiltration = less surface water
  • more leaf cover enables transpiration
• mining -

  • less vegetation = more run off
  • silt in rivers = less storage
• deforestation -

  • less trees = less interception = more surface run off as less water stored
  • decreased transpiration
• dams + reservoirs -

  • less water going underground = more surface water = more evaporation and clouds
• urbanisation -

  • vegetation replaced by impermeable surface = faster overland flow + less infiltration
  • less water returning to storage = reduced water table
  • drains straight to rivers = increased flooding