Global hydrological cycle? Flashcards
What percentage of water does freshwater make up of all water on earth?
2.5%
According to NASA, how many times has every drop of water been consumed and why?
Once, because water flows through a closed hyrdrological cycle
What does solar energy cause water to do?
Evaporate from both sea and land, which then returns as precipitation.
Which two processes drive the global hydrological cycle?
Solar energy: In the form of heat
Gravitational potential energy: Causes rivers to flow downhill and precipitation to fall to the ground.
Levels of what increase in the atmosphere as evaporation increases?
Levels of moisture in the atmosphere increase.
What can higher levels of moisture in the atmosphere cause?
Lead to increased condensation as air cools, and therefore greater precipitation. This explains why some places experience increased cloud cover and precipitation as climate changes.
What are the four main stores of water?
The oceans
Glaciers and ice sheets (cryosphere)
Surface runoff
Atmosphere
What is the biggest store of water?
The ocean, followed by the cryosphere
What is surface runoff in the context of the global hydro logical cycle?
Surface runoff is an umbrella term for a number of land-based stores. These are rivers, lakes, groundwater and the moisture held in soils and vegetation.
What does surface runoff consist of?
Rivers and lakes, as well as groundwater.
What is the largest freshwater store?
The cryosphere is the largest
What percentage of the worlds freshwater is held in the cryosphere?
69%
What percentage of the worlds freshwater is held in groundwater?
30%
What percentage of the worlds freshwater is held in the biosphere (vegetation and soil moisture)?
Less than 1%
What are flows?
Flows are the transfers of water from one store to another.
