Water Cycle Flashcards
what is a system made up of
- inputs
- outputs
- stores
- flows
- boundaries
what is an open system
where both energy or matter can enter and leave
what is an example of an open system
a drainage basin
what is a closed system
matter can’t enter and leave it cycles between stores, energy can enter or leave
what is an example of a closed system
the carbon cycle
what is equilibrium
when the inputs and outputs are balanced
what is dynamic equilibrium
when there are small changes in the inputs and outputs but they still remain balanced
what is a positive feedback cycle
when a change in the input amplifies the output
what is an example of a positive feedback cycle
when temperature rises
sea ice melts
the surface albedo decreases
so the ocean absorbs more heat
temperatures rise
what is a negative feedback cycle
when an input counteracts / nullifies the output
what is an example of a negative feedback cycle
more precipitation means more water for plants to grow
more plant growth leads to more evapotranspiration
this decreases the amount of water for surface run off
what are the earths subsystems
cryosphere - parts of the earth where it is cold enough to freeze
lithosphere - above the mantle
biosphere - living organisms
hydrosphere - water
atmosphere - layer of gas
what % of water is stored as fresh water
3
where is freshwater found and their %
69 = frozen in cryosphere
30 = groundwater
0.3 = lakes, rivers etc
0.4 = water vapour
what are the 2 cryospheric processes
accumulation (adding) and abrasion (taking away)
how do the cryospheric processes affect the water cycle
during cold periods inputs are greater than outputs - water surplus
during warmer periods outputs are greater than inputs - water deficit
what is a drainage basin
the area surrounding the river
what is the water balance
worked out from inputs and outputs
what happens to the water balance during wet seasons
precipitation exceeds evapotranspiration - water surplus
what happens to the water balance during dry seasons
evapotranspiration exceeds precipitation - water deficit
what happens to the water table during winter and spring
more water In the soil percolates down causing the water table to rise
what happens to the water table during summer
the soil moisture is used by plants therefore if there is also little rain there could be a water deficit causing the water table to drop
what are the 3 water cycle transfers
- evaporation
- condensation
- cloud formation and precipitation
what are the 3 types of rain
- frontal rain
- relief rain
- convectional rain
