6.9 - Hydroelectricity

Which three countries are the top producers of hydroelectricity?

• Russia, India, and China

• China, Brazil, and the United States

• Canada, Germany, and Brazil

• Norway, Australia, and Mexico

What is the term for storing water behind a dam to generate electricity?

• Reservoir evaporation

• Water impoundment

• Tidal backing

• Hydrological storage

What is one major advantage of water impoundment (dam) systems?

• Requires no land use

• Produces energy only during floods

• Allows control of electricity production rates

• Does not affect ecosystems

What environmental issue is caused by sediment build-up behind dams?

• Acid rain

• Eutrophication

• Sedimentation

• Saltwater intrusion

How does a "run of river" hydroelectric system differ from a dam?

• It uses wind to push turbines

• It involves a large reservior

• It uses the river's natural current with less flooding

• It can only be used in oceans

Why does damming a river reduce biodiversity in the surrounding ecosystem?

• It increases oxygen in the water

• Creates deeper water with fewer nutrients

• Prevents fish from spawning upstream and changes water temperature

• Increases habitat range for land species

What is a fish ladder used for?

• Measuring fish size before harvesting

• Allowing fish to bypass a dam and migrate upstream

• Feeding fish to control population

• Keeping fish from entering turbines

What is a benefit of hydroelectric dams?

• Increases acidification of nearby water bodies

• Emits high levels of CO2 during electricity generation

• Creates reliable and affordable energy without air pollution

• Reduces jobs in local communities