The Water Cycle Flashcards
what type of system is the hydrological cycle
closed
What is a closed system
system where only energy can be exchanged but not matter
What is the hydrological cycle
circulation of water around the earth
Name the 2 sources that power 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.
What are stores
reservoirs where water is held.
Name the 4 main stores
the oceans (largest by far)
glaciers and ice sheets (cryosphere, second largest)
surface runoff- land-based stores, including rivers, lakes, groundwater and the moisture held in soils and vegetation.
the atmosphere
Of the freshwater stores:
The cryosphere is the largest, holding 69% of global freshwater
Groundwater holds 30%
Less than 1% is stored in the biosphere (vegetation and soil moisture)
What are flows
transfers of water from one store to another.
What are fluxes
rates of flow between stores -> greatest fluxes occur over the oceans.
What does the global water budget do
limits water available for human use
What is the main input of the hydrological cycle
precipitation
Name 5 characteryics that effect the drainage cycle
Form: rain, snow or hail. Clearly, with snow, entry of water into the drainage system will be delayed.
Amount: this will affect the amount of water in the drainage basin and the fluxes within it.
Intensity: the greater the intensity, the greater the likelihood of flooding.
Seasonality: this is likely to result in the drainage basin system operating at different flow levels at different times of the year.
Distribution: this is significant in very large drainage basins, such as the Nile and the Ganges, where tributaries start in different climate zones.
Name the 7 different flows important in transferring the precipitation that has fallen on land
-interception
-Infiltration
-percolation; deep tranfer of water into permeable rocks
-throughflow; lateral transfer of water downslope through soil
-groundwater flow; v slow transfer of percolated water through porous rocks
-surface runoff; when water accumulates in soil until water table reaches surface, forcing further rainwater to run off surface
-river or channel flow
What is interception
retention of water by plants and soils -> evaporated/ absorbed by the vegetation.
What is infiltration
the process by which water soaks into, or is absorbed by, the soil.
What is percolation
a deeper transfer of water into permeable rocks.
What is throughflow
lateral transfer of water downslope through the soil
What is groundwater flow
very slow transfer of percolated water through pervious (permeable) or porous rocks.
What is surface runoff
movement of water that is unconfined by a channel across the surface of the ground. A.k.a. overland flow.
What is river/ channel flow
takes over as soon as the water enters a river or stream; the flow is confined within a channel.
Name the 3 output processes
-evaporation
-transpiration
-discharge
What is evaporation
when moisture is lost -> atmosphere from water surfaces, soil and rock.