(Vocabulary located at bottom of page)
Water Supply
Water
Distribution-
Drinkable
freshwater is not distributed evenly around the globe. There are larger
and smaller quantities at different locations around the world. Freshwater
is most concentrated in surface water sources such as lakes and rivers.
It can be found as groundwater just the same.
Surface
Water-
85% of the total water on earth is from the 28 largest lakes. Lots of these
lakes are found in North America and Asia. 25% of the total volume of the
world's lake water is found in Lake Baikal located in Russia.
The distribution of runoff, extra freshwater that flows out of rivers,
is also concentrated in the places it's found. In South America and Asia
near 56% of the world's runoff occurs. Australia only contains 1% of the
world's runoff, Europe 7%.
*Groundwater-
It is harder to measure amounts of groundwater than water from lakes and
rivers though it is a good source of water. In many places the rate of
water pumped from the aquifers override the rate that the aquifers
are replenished by water sources such as rain, floods, etc. In areas with
that problem the water table decreasing because of overuse. Saudi
Arabia's aquifers, for example, are so overused that it is more expensive
in that country to pump out water from their aquifers than it is to remove
salt from sea water.
Vocabulary-
*Acid
Rain--Rain that is slightly acidic due to the chemicals, such as exhaust
from cars, etc.. that has been mixed with water vapor and precipitated
as acid rain.
*Aquifers--A
formation of rock that is deep underground that has water within it.
*Water
Table--The ground flat land underneath the ground where groundwater is
found.
