Hydrologic Cycle Flashcards
what is the hydrologic cycle?
the movement of water in its various solid, liquid, and gaseous phases between sources and sinks
what are the primary reservoirs of water at the earth’s surface? what are the smaller reservoirs?
the oceans are the primary reservoirs with ice caps and groundwater acting as much smaller reservoirs
what powers the hydrologic cycle?
(energy from) the sun
why are ice caps and groundwater reservoirs important for humans and animals?
they contain freshwater unlike the ocean, the earth’s largest hydrologic reservoir and humans can’t use salt water for agriculture or drinking
how does water travel from the bio/hydrosphere to the atmosphere during the hydrologic cycle?
evaporation and evapotranspiration move water from a liquid on earth to a gas in the atmosphere
what is transpiration?
a process in which plants draw groundwater using their roots to reach their leaves through the exhalation of water vapor through the stomata.
why is evaporation/evapotranspiration called vaporization?
because liquid water becomes water vapor (gas) in the atmosphere
how do plants accomplish transpiration?
they open the stomata on their leaves, allowing water to evaporate into the atmosphere from the leaf
this makes the leaf have a lower water potential than the roots, which draws water up through the roots to replace the evaporated water and even the water potential gradient
what is evapotranspiration?
the amount of water that enters the atmosphere from transpiration and evaporation combined
what are the steps of the hydrologic cycle?
evaporation, transpiration, condensation, precipitation, infiltration, and runoff
what is an aquifer? how is it used?
an underground layer of water-bearing, permeable rock; groundwater from aquifers can be extracted using a water well
how are runoff and infiltration connected?
they are both the step after precipitation in the hydrologic cycle
rain either flows over the earth’s surface into a body of water or trickles through soil down into groundwater aquifers
groundwater/aquifers and surface waters/bodies of waters are important what?
they are important freshwater reservoirs for humans and animals
how does precipitation recharge groundwater?
precipitation recharges groundwater through infiltration but only if the ground is permeable
what is good and bad about runoff in the hydrologic cycle?
runoff recharges surface waters but can also carry pollutants into water sources
