Introduction-Water Shortage (2)

Introduction-Water Shortage (2)

1. over 1 billion ppl in world do not have clean water to drink

2. Occurs when level of water usage exceeds water supply available

3. Distribution of water on earth

   • Of all water on the earth, 97.2% is ocean water (undrinkable)
     • Only 2.8% is freshwater
       • 68.6% of that is locked up in ice caps and glaciers
         • Ice cap is a thick, continuous mass of ice that covers large areas of land
           • Major ice caps and glaciers: Greenland,Antartica
             • Others: China, South and North America
         • Glacier is a body of ice that moves down a slope due to gravity
       • 1.3% is surface water (rivers, lakes)
         • A river is a natural stream of fresh water flowing along a definite course into another water body
           • Possible sources: lake,spring,melting glacier
           • Smaller streams that add to the flow are called tributaries
           • The end of a river is called a mouth
             • Mouth usually empties to a lake or ocean
             • Largest river drainage basins: Mississippi, Amazon, Nile, Yangtze, Yenisey, Congo, Mackenzie
       • 30.1% is groundwater (wells)
         • Stored underground in soil and underlying rocks
           • When rain falls, some water infiltrates the ground. These are known as groundwater
         • Most abundant supply: South America and Africa
         • Many countries use groundwater for irrigation
           • Largest areas irrigated with groundwater: India, China, US
       • Lake is a body of water occupying a hollow in the earth's surface
         • Lake Huron, Lake Superior, Lake Ontorio, Lake Michigan, Lake Baykal, Lake Victoria, Lake Erie

4. Locations in the world facing water shortage

   • Fresh water availability: Country's total water resources divided by total population
     • Water scarcity and water stress: most of Africa
   • Northern Africa facing water scarcity (natural)
     • One of the driest areas in the world- low rainfall
   • Aral Sea in Middle East (once the 4th largest lake in world) - caused by human activities
     • People use water for large-scale irrigation projects for crops
       • Aral Sea began to shrink drastically

Images and files in the map