Chapter 2C Section 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 your body, but some is lost every day. Without water, a person cannot live for 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 IrrigationSpray 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.

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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.

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 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 –