1.B - the water cycle as a system Flashcards
what are the main stores of water?
- oceans
- polar ice and glaciers
- groundwater/aquifers
- lakes
- soils
- atmosphere
- rivers
- biosphere
how much water do the oceans store?
- 137,000 thousand cubic kilometers
- 97% globally
how much water does the land store?
- 39,000 thousand cubic kilometers
- 0.7% globally
what is worrying about the amount of water stored in polar ice and glaciers?
- as they melt due to global warming this will greatly increase the volume of water in oceans = SL rise = flooding
what challenges are there with most of the water being stored in oceans?
- 97% of water stored in our oceans
- salt water = toxic to most crops and also can’t be drunk by humans
- desalinisation is very expensive and quite inefficient
what are aquifers?
water bearing bands of porous/permeable rock
what are ice sheets?
floating sheets of ice permanently attached to a land mass
what are the flows in the water cycle system?
- evapotranspiration
- precipitation
- ablation
- infiltration
- run off
- groundwater flow
define evapotranspiration
combined loss of water at the surface through evaporation and transpiration by plants
define precipitation
moisture (rain, snow, hail) falling from clouds towards the ground
define ablation
the loss of ice and snow, especially from a glacier, though melting, evaporation and sublimation
define infiltration
the vertical movement of rainwater through the soil
define run-off
the movement of water across the land surface
define ground-water flow
the horizontal movement of water w/in aquifers
what does condensation refer to?
- condensation refers to the change of state from water vapour into liquid water.
- clouds form as a result of condensation in the atmosphere.
- this will happen when air is cooled so that it reaches its dew point.
in what ways does air reach the dew point?
- it can occur when air rises upwards due to being warmer than surrounding air (convection). As the air rises, its pressure drops and it expands and cools until its dew point (adiabatic expansion)
- air can be forced to rise over mountain barriers and so again it cools by aidiabatic expansion as it rises
- air may also be forced to rise as it meets colder air at a front
- finally if a mass of air will cool if it moves across a relatively cooler surface (advection). this may happen as air moves from sea to land in the winter
what is a cumuliform cloud?
- flat bases and considerable vertical development
- form when air is heated locally through contact w/ the Earth surface
- this causes heated air parcels to rise freely through the atmosphere (convection), expand (due to the fall in pressure w/ altitude) and cool
- as cooling reaches the dew point, condensation begins and clouds form
how do cumuliform clouds form?
- form when air is heated locally through contact w/ the Earth surface
- this causes heated air parcels to rise freely through the atmosphere (convection), expand (due to the fall in pressure w/ altitude) and cool
- as cooling reaches the dew point, condensation begins and clouds form