Earth: The Water Planet
What percent of the water on
Earth is good enough to drink?
Water on Earth
• 97% = Salt Water, Oceans, Seas, some
lakes and groundwater
• 2.4% = Glaciers and Ice Caps
• ≈ 0.6% = Fresh water that is unavailable,
Too far underground or polluted
• 0.03% = Water To Drink
The Hydrologic Cycle
AKA: The Water Cycle
Aquifer
Places Water is stored
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Reservoirs
Aquifer
Rivers, Streams
Lakes
Oceans
Glaciers & Ice Caps
Plants and Animals
Aquifer
• Water stored in the ground
• Ground water
Glaciers and Ice Caps
• Glaciers and Ice Caps hold (or held) about
80% of all fresh water on Earth.
• However they are shrinking fast due to
global warming.
How Water Moves
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Precipitation
Evaporation
Condensation
Percolation
Transpiration
Irrigation
Ground water pumping (Wells)
Run Off
Percolation
When water moves downward
between spaces in the soil and
bedrock.
Permeable
• Something that water can pass though
Impermeable
• Something water can not pass through
Transpiration
• The movement of water by plants as they
breath. Water is drawn up from the soil by
roots and “exhaled” through leaves as the
plant breaths.
Irrigation
To supply water to crops and such
by pumping or diverting it from a
river or other body of water
Run Off
• When water travels over the surface of the
ground (after a hard rain)
• Water can collect contaminates like oil and
gasoline from roads and animal wastes
from yards and farms. (this is an example
of non-point pollution)
Non-point Pollution
Pollutants from a source that is difficult to
pinpoint. They include chemicals from lawns
and fields, trash, oil, and animal and human
wastes. Typically, water running off of streets,
parking lots, yards, construction sites and
agricultural lands sweep these pollutants into
bodies of water when it rains. About 70
percent of pollution in the nation's waters
come from nonpoint sources.
www.lcra.org/water/glossary.html
Point Pollution
• Pollution that can be traced to a single
source or point, such as a sewage
treatment plant, outfall, or other discharge
pipe.