Chapter 2CSection 1

Fresh water is an essential resource.

Fresh water supports life.

Our bodies are more than ½ water.• Without water in your blood, your

cells would not receive the nutrients you need.

• Skin and tissues hold water in yourbody, but some is lost every day.

• Without water, a person cannot livefor more than a few days.

• Without water, people wouldn’t be able to grow food.

Fresh water on Earth is a limited resource.

• If too much water is taken from aquifers, the supply will eventually run out.

• If the water in rivers and lakes becomes polluted, we can no longer use it.

Most human activities require water.

• Farming• Industry• Transportation and Recreation• Fisheries and Aquiculture• Energy

Farming

• In U.S., about 40% of the water that is used goes to growing crops and raising livestock.

• Irrigation – in drier areas, farmers draw water from aquifers, rivers, or lakes to grow crops

1. Flood irrigation – pours water through canals and waterways so that it flows through the fields

2. Spray irrigation – sprays water onto the fields

Irrigation

• Flood Irrigation • Spray Irrigation

Industry

• Making cars – begins with the mining of minerals and ends with the final washing

• Huge amounts of water are used to cool down machines.

• Coal mine – water is used to separate chunks of coal from other clumps of dirt and rock

• Paper mill – uses 100 to 300 metric tons of water to manufacture one ton of paper

• Factories can clean the water they use and return most of it to lakes and rivers

Industry

Transportation and Recreation

• In the U.S., major rivers and the Great Lakes provide an efficient way to transport goods.

• On the Great Lakes, large ships carry iron ore from Minnesota to cities where it is used to make steel.

Continued…

• Whitewater rafting, canoeing, and kayaking• Along the shores – camp, picnic, swim, and fish

Continued…

• A river may flow too fast or be too shallow for safe travel, so people dig channels called canals that bypass rough spots and connect waterways.

Fisheries and Aquaculture

• Rivers and lakes provide fish for our food and also provide food for frogs, insects, birds, and larger mammals.

• Aquaculture – the science and business of raising and harvesting fish in a controlled situation (provide a cheap, ready source of catfish, trout, and salmon)

• To help maintain the population of fish in rivers and lakes, fish hatcheries are used to raise fish to release into lakes and rivers.

Continued…

Energy

• Dam – a structure that holds back and controls the flow of water in a river or other body of water

• Hydroelectric dam – water rushing through the dam turns machines called turbines, generating electricity

• Many plants us coal or nuclear power to heat water, creating steam that turns the turbines.

• Nuclear power stations also use water to cool the system.

Energy

• http://www.duke-energy.com/about-energy/generating-electricity/nuclear-how.asp

• http://www.duke-energy.com/about-energy/generating-electricity/pumped-storage-how.asp

• http://www.duke-energy.com/about-energy/generating-electricity/coal-fired-how.asp

Dams and other structures alter rivers.

• When a dam is built on a river, the landscape and the shape of a river are greatly changed.

1. Below the dam, the speed and volume of water flow may change, making a new ecosystem.

2. Behind the dam, water may collect and form a lake covering what once had been a river valley.

http://www.learnnc.org/lp/media/uploads/2008/09/three_gorges.jpg

Reservoirs

• A reservoir is a lake that is used to store water.1. Many communities rely on reservoirs for their water

needs.2. They provide opportunities for boating and other

recreational activities.

Locks

• A lock is a section of waterway, closed off by gates, in which the water level is raised or lowered to move ships through.

• They are used in canals and rivers that connect lakes of different elevations.

• They are used in canals that slope upward then downward, such as the Panama Canal.

• The Panama Canal is dug into a strip of land between the Atlantic and Pacific Oceans, allowing ships a handy shortcut.

The Welland Canal

• The Welland Canal was built to connect Lake Ontario and Lake Erie.

• The southern end, on Lake Erie, is 326.5 ft. higher than the northern end on Lake Ontario.

• There are a series of 8 ship locks to raise and lower the ships as they navigate the canal.

• The length is 26 miles, and it takes ships an average of 11 hours to traverse the entire length.

The Welland Canal

Locks– https://www.youtube.com/watch?NR=1&v=U15Fwo9tbJ4&feature=endscreen&safe