Water Cycle - Global Distribution Flashcards
Explain water distribution type
97% saline water in oceans
- 5% fresh water (69% ice and glacier, 30% ground water, 1% river and lakes)
- 5% brackish water
Explain the 4 stores of water
Lithosphere - land based storage (freshwater) small. Eg rivers, streams, puddles, ponds etc
Hydrosphere- liquid water - large - eg oceans - Pacific
Atmosphere - air and clouds, small. 90% all moisture in air from evap. (Warm air holds more water vapour than cold air) 10% from transpiration
Cryosphere- frozen water - snow and ice (large first big mostly medium)
FW- permafrost- 100s m down - sun top melt
FW- glaciers- 100s m snow compacted - ice. Glacier
FW- ice caps/sheets - glaciers but bigger
S- sea ice
Distribution of worlds oceans
Pacific Ocean - 70% of earths surface and largest body of water
Taking up 1/3 of planets surface
Distribution of worlds lake
No pattern
A lot of lakes situated in North America/ Canada/Africa
Eg Lake Chad Central Africa
Issues: drying up —> dec in quantity of water - provides water and livelihoods for 30 mill people in surrounding countries eg Libya, Nigeria - water supply running out. Climate change, inc pop and unplanned irrigation since 1960s
This is as: population, irrigation strategies intercepting/diverting water onto their farms etc inc temp = inc evap, construction of damns reduces amount of water transferred to lake
Global distribution of stores
Aquifers
Aquifers: water stores in permeable rock eg chalk, limestone.
Fossil aquifer: ancient groundwater stored in permeable rock
30% fresh water stored in ground water - can get water from it
Aquifers everywhere
FA in Africa.
Aquifers important in droughts and uncontaminated
Aquifers are where lots of permeable rock and high rainfall
Problem with extracted = lead to sea water filling gaps - saline- contaminate
FA will run out of take out
Fluctuations in water table (issue if goes above borehole)
Major aquifers: Nubian sandstone (FA) and North West Sahara aquifer system —>
Fossil aquifers in deserts of African, Middle East and Australia formed 1000s yrs ago - in ice age - not much rain now
Global distribution of stores
Ice sheets and caps
Himalayas- colder part of world - snow - compresses glacier = ice cap [many = ice sheet]
Largest store of water
Ocean
Freshwater types
Groundwater
Rivers
Lakes
Etc
Drinking water types
Aquifers
Groundwater
Rivers
Lakes
Global warming does what to water stores
More evap - less in lake etc - more in ocean as ice caps melt.
Why did atmosphere small amount of water
Transit
Problem with unequal distribution of water, ice etc
Some country water supply drying up - lower
FA- not sustainable
Some don’t have access to any freshwater - expensive to transport
