Water Resources Flashcards
The majority (97.5%) of Earth’s water resides in…
oceans and is too salty to drink or use for irrigation.
Only _____ is of Earth’s water is considered fresh water.
2.5%
fresh water
water relatively pure and free from salts
surface water
located atop Earth’s surface (i.e. river/lake)
groundwater
water beneath surface that reside within pores in soil or rock
Water that does not evaporate, flow into waterways, or get taken up by organisms will…
infiltrate the groundwater.
Groundwater can remain underground for…
1000s of years.
aquifers
porous, spongelike formations of rock and sand
Groundwater is contained within…
aquifers.
water table
upper border or layer completely filled with water
recharge zone
any area where water can infiltrate through surface and reach the aquiferCon
What is the difference between confined and unconfined aquifers?
Confined aquifers are trapped between impermeable clay; Unconfined aquifers are not.
Ogallala Aquifer
largest known aquifer located under Great Plains of the US
Water of the Ogallala Aquifer is being withdrawn…
much faster than it can be recharged, resulting in reductions in volume in many places.
The area of land drained by a river system and all of its tributaries makes up…
that river’s watershed.
wetlands
systems where soil is saturated with water often containing standing shallow water
Wetlands provide water-related ecosystems services including…
(1) slowing runoff
(2) reducing flooding
(3) recharging aquifers
(4) filtering pollutants
Wetlands have been heavily impacted by human activities including…
(1) draining and filling for agriculture
(2) withdrawing water for irrigation
(3) construction of dams
Fresh water and human populations are…
unevenly distributed around Earth.
Climate differences and other factors have created…
varying amounts of groundwater, surface water, and precipitation across Earth.
In US, agriculture comprises of _____ of fresh water use.
41%
In US, domestic and municipal comprises of ____ of fresh water use.
10%
In US, energy production comprises of _____ of fresh water use.
38%
Increased demand for irrigation has led to…
consumptive use of aquifers and surface waters.
consumptive use
removing water for use, but do not return it
nonconsumptive use
does not remove or only temporarily removes water from source for use (i.e. hydroelectric dams)
water mining
withdrawal of water faster than it can be replenished
Aquifer depletion occurs when…
water withdrawals exceed recharge rates.