The Water Cycle Flashcards
Is the world a closed or an open system?
Closed system driven by solar and gravitational potential energy
What is a closed system?
A system that has no external inputs or outputs
What two powers drive the hydrological cycle?
Solar energy: in the form of heat
Gravitational potential energy: causes rivers to flow downhill and precipitation to fall to the ground
What is a store?
Stores are reservoirs where water is held
What are the four main stores?
Oceans
Glaciers and ice sheets
Surface runoff (rivers, lakes, groundwater)
The atmosphere
How much water does the worlds Cryosphere hold?
69% of the worlds freshwater
How much water is held in groundwater?
30%
How much water is held in the biosphere?
Less than 1%
What is the global water budget?
The global water budget takes into account all the water that is held in stores and flows
What is a residence time?
The average time a molecule of water will spend in stores
What two water stores are un renewable?
Fossil water
Cryosphere
What is fossil water?
Ancient, deep groundwater made from wetter periods in the geological past
What is the Cryosphere?
Made up of snow and ice
Why is the Cryosphere non-renewable?
Because we have to wait for another Ice age
How much of the worlds water budget is accessible to humans?
1%
How much of the worlds water is in the oceans?
97.5%
How much of the worlds water is fresh water?
2.5%
How much of the worlds fresh water is in ice caps and glaciers?
69%
How much of the worlds fresh water is in groundwater?
30%
How much accessible surface water is in lakes?
52%
How much accessible surface water is soil moisture
38%
How much accessible surface water is in atmospheric water vapour?
8%
How much accessible surface water is in rivers?
1%
How much accessible surface water is in plants?
1%