The Water Cycle Flashcards
4 global stores of water
oceans
lakes
aquifers
cryosphere
what type of system is the global water cycle
closed
how much freshwater is held in the cryosphere
70%
how much freshwater is held in lakes
20%
how much water is accesible
1.3%
how much water is stored as aquifers
30%
where are aquifers found
in porous and permeable rocks such as limetsone and sandtsone
cryosphere stores
sea ice
permafrost
ice caps
glaciers
what are the 5 subsytems
cryosphere
biosphere
lithosphere
hydrosphere
atmosphere
largest store in the global water cycle
oceans 97%
features of flashy hydrographs
short lag time
higher flood risk
high peak discharge
features of subdued hydrographs
long lag time
le
what is the water balance
the balance between inputs and outputs
what is required for there to be a river
stores can release water
direct precipitation and
overland flow into river
when does evapotranspiration increase
when it is warmer, and atmosphere can hold more water vapour than the amount of water available
soil water budget - winter uk
precipitation is greater than potential evapotranspiration and soil is in a water surplus
soil water budget- spring uk
potential evapotranspirtion exceeds precipitation
soil water budget- summer uk
there is a deficit of soil water. river levels fall
soil water budget-autumn
soil water is fully recharged and precipitation exceeds evapotranspiration
what is river discharge
the amount of water in a river flowing past a particular point expressed as m3s-1 (cumecs)
bankfull
maximum discharge that a river channel is capable of carrying without flooding
lag time
time between peak rainfall and peal discharge
factors which interect with river discharge
water resources
water related structures
flood alleviation schemes
why are storm hydrographs important
they can predict how a river might respond to a rainstorm