AP Environmental Science : Water Resources

Study concepts, example questions & explanations for AP Environmental Science

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Example Questions

Example Question #1 : Water Resources

What percent of the Earth's water is readily available for drinking and agriculture?

Possible Answers:

1%

5%

50%

25%

3%

Correct answer:

1%

Explanation:

97% of the Earth's water is saltwater and unusable for drinking or farming. of the 3% that is actually freshwater, 2% is frozen in glaciers, leaving humans with 1% of all water on earth to use for farming. 

Example Question #2 : Water Resources

All of the following characteristics apply to the riparian zone except __________.

Possible Answers:

biofilters

wildlife corridors

high species diversity

high sun exposure

Correct answer:

high sun exposure

Explanation:

Shade provided by the riparian zone is crucial to stream temperature regulation.

The riparian zone is the edge of a river or stream, therefore it has high biodiversity due to edge effects. Biofilters in the riparian zone protect the aquatic environment it surrounds. Also, because the riparian zone spans distances of an aquatic environment's edge, it serves as a corridor for wildlife.

Example Question #2 : Water Resources

The Great Lakes of North America represent the largest source of freshwater on the planet. Approximately how many years ago did the Great Lakes form?

Possible Answers:

10,000,000 years ago

100,000,000 years ago

10,000 years ago

100,000 years ago

Correct answer:

10,000 years ago

Explanation:

The correct response was 10,000 years ago. The Great Lakes formed during glacial recession of the most recent glaciation. This most recent glacial recession occurred between 10-15 thousands years ago. As the glaciers receded northward across North America, melting glacial waters drained and formed what is now known as the Great Lakes. 

Example Question #3 : Water Resources

About 2% of the Earth's water supply is suitable for human and plant consumption. 98% of Earth's water is found in the oceans and is too salty for human or plant consumption. 

Where is a majority of Earth's fresh water found?

Possible Answers:

Aquifers 

Polar ice caps/glacial ice

Rivers

Lakes

Ground water

Correct answer:

Polar ice caps/glacial ice

Explanation:

Lakes, streams, rivers and ground water account for about a half a percent of the fresh water found on Earth. 

Example Question #3 : Freshwater

Freshwater is a necessary resource for human survival. Approximately what percent of the Earth's water supply is found in freshwater resources that are groundwater deposits (i.e. rivers, lakes, and streams)?

Possible Answers:

2.0%

0.02%

20%

0.2%

Correct answer:

0.02%

Explanation:

The correct response is 0.02%. The rest of the water resources are either too salty, too deep, or too cold in frozen icecaps. 

Example Question #2 : Water Resources

Desalinization plants are becoming popular in the Middle East and heavily proposed in drought states like California to satisfy the public's use of fresh water. What is the dominant issue with establishing desalinization facilities?

Possible Answers:

Most of our planet's oceans are heavily polluted and desalinating sea water will remove the salt, but harmful pollutants and toxins that affect human health can remain present. 

The National Environmental Policy Act (NEPA) requires environmental impact statements be conducted for any federally-funded project, and involves too much red tape for a desalinization plant to be economically feasible. 

Desalinization requires a lot of heat energy to create freshwater vapor, and is generally a very expensive process. 

Desalinization removes most of the salt content, but not all of it, posing a serious risk of dehydration or heart problems when consumed by humans. 

Building desalinization facilities offshore is legally difficult due to international regulations on ocean management. 

Correct answer:

Desalinization requires a lot of heat energy to create freshwater vapor, and is generally a very expensive process. 

Explanation:

Desalinization involves heating seawater to a boil, resulting in pure, distilled water vapor with no impurities. While any ferally-funded project is subject to environmental assesments, the major roadblock for these facilities is the heat energy required to distill the seawater. 

Example Question #3 : Water Resources

In sea water, carbon is mostly found in the form of __________.

Possible Answers:

phosphoric acid

glucose

carbon monoxide

bicarbonate ions

methane gas

Correct answer:

bicarbonate ions

Explanation:

When atmospheric carbon dioxide reacts with ocean water, they combine to product the bicarbonate iron, or . This ion acts as a buffer in the sea water, allowing the pH to remain relatively stable. While neither methane, glucose, nor carbon monoxide occur in large enough quantities in salt water, phosphoric acid actually contains no carbon.

Example Question #2 : Water Resources

Aquifers provide water for millions of people. But when aquifers are used at faster rate than they can replenished a deficit occurs which causes a number of problems. 

What is it called when aquifers in coastal areas start to fill with ocean water?

Possible Answers:

Groundwater

Confined

Artesian

Depletion

Saltwater instusion

Correct answer:

Saltwater instusion

Explanation:

Aquifers are part of groundwater. Saltwater intrusion occurs because of aquifer depletion. The empty space can then be filled with sea water. Confined and artesian are types of aquifers. 

Example Question #1 : Water Resources

Which of the following is not a reason that plants transpire?

Possible Answers:

To promote gas exchange with the environment

To allow uptake of CO2 from the atmosphere

To prevent leaves from overheating

To conserve water

To carry soil minerals into the leaves

Correct answer:

To conserve water

Explanation:

Transpiration invovles the opening of the stomata pores on the surface of the plant's leaves. When the pores are open, water is able to evaporate and be released from the plant. The result is a negative pressure differential that helps pull water upwards via capillary action through the xylem. Water is lost during transpiration, not conserved.

Example Question #1 : Water Resources

Approximately what percent of fresh water is readily available in bodies of above-ground water?

Possible Answers:

Correct answer:

Explanation:

Fresh, above-ground water (rivers, lakes, reservoirs, etc.) compose roughly 0.5% of all fresh water on earth.

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