3.2.2 The Hydrosphere Flashcards
What is the hydrosphere?
The hydrosphere includes all the water on Earth, including oceans, rivers, lakes, and water in the atmosphere.
What is the global hydrological cycle?
The global hydrological cycle is the continuous movement of water through the oceans, atmosphere, and continents, maintaining dynamic equilibrium.
What is the main process by which water moves from oceans to the atmosphere?
Evaporation from the oceans.
How much water evaporates from the oceans annually in the global hydrological cycle?
413 units
What term describes water movement from continents to oceans through rivers?
Channel runoff
What are the two forms of water transfer from continents to the atmosphere?
Evaporation and transpiration.
What is “dynamic equilibrium” in the context of the global hydrological cycle
It refers to the balance maintained in the water cycle, where inputs and outputs remain relatively constant over time.
How much water is transported from the oceans to the atmosphere above the sea?
373 units
How much water is transported from the oceans to the atmosphere above land?
40 units
How much water precipitates onto land from the atmosphere?
113 units
How much water is transferred to the atmosphere from land through evaporation and transpiration?
73 units
How much water is transported from land to oceans via channel runoff (rivers)?
40 units
What is transpiration
Plants adsorb soil moisture via their roots & give off water vapour through pores on their leaf surfaces
What is evapotranspiration
Flux of water from the earth’s surface to the atmosphere via the process of evaporation and transpiration
What percentage of the Earth’s water is in the oceans (saltwater)?
97.5%
What percentage of the Earth’s water is freshwater?
2.5%
What percentage of freshwater is stored in the cryosphere?
68.7%
What percentage of freshwater is stored as groundwater?
30.1%
What percentage of accessible surface freshwater is in lakes?
52%
What percentage of accessible surface freshwater is in soil moisture?
38%
What percentage of accessible surface freshwater is in rivers?
1%
What is the residence time of water in oceans?
3,600 years
What is the residence time of water in the cryosphere?
15,000 years
What is the residence time of water in groundwater?
10,000years
What is the residence time of water in rivers and lakes?
2 weeks to 50 weeks
What is the residence time of water in rivers and lakes?
2 weeks to 50 weeks
What is the residence time of water in soil moisture?
2 weeks to 10 years
What is the residence time of water in the atmosphere?
7 years
What is the residence time of water in the biosphere?
10 days
What is “residence time” in the context of the hydrological cycle?
The average time a water molecule spends in a store.
What percentage of all water falls as precipitation each year and where does most water remain
0.035%.
Most water remains in the stores, unavailable for use
What can releasing more water from storage cause and why
Increases yearly budget because if it has a long residence time its is exploiting a non-renewable resource
Explain the global water distribution
Although water is a renewable resource, it’s unevenly distributed around the world. Precipitation isn’t consistent throughout the year
Give ways how humans may try to solve problems of inconsistent supply over a year
Storing water
Abstracting water from aquifers
Abstracting water from rivers and lakes
Transforming water from one place to another
Desalinating water
Why is demand for water rising
Global population rise
Increased irrigation (70% of global water supply is used in farming)
Industrialisation
Increased per-capita use
