5.1 The global hydrological cycle is of enormous importance to life on earth Flashcards
Store -
Reservoirs where water is held like the ocean
The hydrological cycle is classed as open or closed?
Closed - fixed amount of water in the earth atmosphere system.
Fluxes -
Measure the rate of the flow between the store
Processes -
Physical mechanisms which drive the fluxes between the stores
The hydrological cycle is driven by what two types of energy?
Solar and gravitational potential.
Importance and size of water stores - Cryosphere
Last ice age more water was held within the cryosphere (area which are frozen or snow). Contain on average 1.9% global water
Ocean stores -water storage
Vast majority stored in liquid from holds around 97% of the global water.
Atmosphere - water storage
Water largely exists as water vapour in the atmosphere (its carrying capacity directly links to temperature) holds 0.001%
Biosphere - water storage
On the land water stores are in rivers, streams and lakes. This is blue water the visible areas of water. Water can also be stored in vegetation through interception this is known as green water. In the biosphere it contains 0.2% of water.
The water budgets limit use for humans this is based from the idea water stores have different?
Residence times - average time the water molecules spend in each store.
Some waters are non-renewable like fossil water
Groundwater which is deep seated and not available for human use is deemed fossil water like under the Sahara desert.
How much water is ground deep and unaccessible?
30%
How residence time affect accessible stores?
Soil moisture, small lakes and rivers have a shorter residence time and is spread very thinly across the earths surface it is easily lost to other stores by evaporation and transpiration.
How much freshwater is locked up in ice?
69% this water is largely inaccessible for human use but some use the meltwater for the greater good. (Glacier case studies)
