6.1 Water Resource and Uses (ground water and aquifers (aquifers: An…
6.1 Water Resource and Uses
freshwater use and availability
0.93(saline ground water) 0.07(saline lakes
1.3 % surface water and other fresh water
other (atmospheric water, soil moisture, rivers,swamps)
ice and snow 73.1
68.6 glaciers and ice caps
only 0.024% readily available as liquid freshwater
hydrolic cycle, purified, reused etc.
ground water and aquifers
ground water is our biggest source of drinkable water
aquifers: An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt). Groundwater can be extracted using a water well.
aquifers are like large elongated sponges, they prevent water from further sinking into the earth.
Most aquifers are naturally recharged by rainfall or other surface water that infiltrates into the ground
confined: Confined aquifers are those in which an impermeable dirt/rock layer exists that prevents water from seeping into the aquifer from the ground surface located directly above.
unconfined: Unconfined aquifers are those into which water seeps from the ground surface directly above the aquifer
Artesian well, well from which water flows under natural pressure without pumping.
pollution last decades or centuries
sinking of land
useful for drinking and irrigation
freshwater is being used unsastinably
using it faster than it can replenish
overload with pollutants
this causes environmental and economical problems
poses a threat to food production
virtual water makes up a large part of our water footprints, especially in developed nations
freshwater is decreasing also due to climate change
solutions to ground water depletion
subsidize water conservation
stop growing water intensive crops in dry areas
use water more efficently
tax water pumped from wells
build rain gardens in urban areas
increase freshwater availability