The document discusses the Earth's freshwater hydrosphere and freshwater resources. It describes how only 3% of the Earth's water is freshwater, with most as ice (76%) or underground (23%). Less than 1% is available as surface water. It also outlines the water cycle powered by the sun and discusses different types of surface water like rivers, icebergs, and glaciers as well as groundwater stored underground in aquifers. Wetlands are also described as important habitats. Freshwater resources are then discussed, including drinking water supply and protection, as well as pollution sources like point and nonpoint pollution.

1. The Earth’s Freshwater Hydrosphere
Fresh water
I. water on earth
a. remains fairly constant
b. 97% is salt, 3% is fresh (not salty)
c. of the 3% fresh, 76% - ice; 23% is underground
d. less than 1% of the 3% - available surface water
II. water cycle
a. powered by the sun
b. evaporation – from liquid to gas – increased heat energy
c. condensation – from gas to liquid – cooling/decreased heat energy
d. precipitation – falls back to Earth - gravity
e. transpiration – water vapor given off by plants – a form of evaporation
III. water on the surface (surface water)
a. river systems (river and all of its tributaries)
b. icebergs and glaciers - most of the earth’s fresh water
IV. underground water (groundwater)
a. aquifer – underground rock layer that stores water
b. water table – upper boundary of saturated zone
c. permeable – pores (spaces) allow water to pass through
d. impermeable – does not allow water to pass - bedrock
e. saturated – filled with water
V. Wetlands -land covered part of the year by shallow water – protected; they are important
habitats during the life cycle of many species. Two of the largest wetlands in the USA are the
Everglades in Florida and the Okefenokee Swamp in GA.
Chapter 12 Freshwater Resources
I. water supply - drinking quality must be protected
a. water shortage - too little water or too great a demand in an area (or both)
b. our water source - Lake Lanier
c. water conservation - protecting water supply (use less, use more efficiently)
II. freshwater pollution
a. water pollution - any addition of a substance that has a negative impact on the water supply
b. sources of water pollution
i. point source pollution – coming from a specific and identifiable place or pipe
ii. nonpoint source pollution – problem is from a wide area and cannot be traced back to
one place