Zusammenfassung der Ressource
Introduction-Water Shortage (2)
- over 1 billion ppl in world do
not have clean water to drink
- Occurs when level of water
usage exceeds water supply
available
- 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
- 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