4.1

• water table - The solid layer under ground above groundwater supplies (aquifer)
• • Direct use of water - domestic and personal use of water
• • Indirect uses - industry and agriculture
• worldwide water uses

  • 73% - Agricultural
  • 22% - Industrial
  • 5% - Domestic
  • >1% - Reservoir Losses
• agricultural -

  • 73% of all water used by people is used in agriculture (irrigation)
  • provides food, jobs and products for a country
  • over irrigation can reduce crop growth, and deplete groundwater supplies
• industrial -

  • Industry uses water as a coolant, solvent, for washing & diluting pollutants when releasing them into the environment
  • Government controls industry’s water use through regulations
  • Industry provides jobs, products & services, but also can contribute to pollution and depletion of water
• domestic -

  • Water use in the home
  • Showering, flushing the toilet, cooking, cleaning
• reservior losses - water lost to evaporation, transpiration, and runoff
• dams advantages

  • Recreation
  • Hydroelectricity
  • Flood Protection
  • Irrigation (if low rainfall)
  • Employment
  • Shipping
• dams disadvantages

  • Water flow decreases
  • Salinity increases at river’s mouth
  • Habitat displacement and destruction
  • Migration disrupted
  • Fish need special ladders to swim upstream
  • Sedimentation
  • Sedimets trapped and nutrients aren’t available to plants and animals downstream
• • Power Stations:
  • Discharge warm water into lakes or rivers
  • Can kill organisms or cause excessive plant growth
• • Factories:
  • Might add dangerous chemicals to the water or thermal pollution
  • This can kill organisms, cause mutations or negatively impact organisms reproduction
• • Oil Spills:
  • Harm animals in, or near the water
• • Sewage:
  • contains Large amounts of nitrogen which causes number of microorganisms to increase
• • Runoff (Farms):
  • Fertilizers that cause excessive plant growth
  • May also contain herbicides/pesticides that harm organisms
• • Runoff (City):
  • Large amounts of oil, salt and other chemicals
  • Negatively affect plants and animals