Hydrology Test Review

What percentage of Earth's surface is covered by water, and how much of that is fresh water?

• 70% covered by water, 3% is fresh

• 50% covered by water, 10% is fresh

• 80% covered by water, 5% is fresh

• 60% covered by water, 2% is fresh

Answer explanation

About 70% of Earth's surface is covered by water, with only 3% of that being fresh water. This makes the first answer choice correct, as the other options underestimate both the total water coverage and the fresh water percentage.

Tags

NGSS.MS-ESS2-4

What is the largest consumer of fresh water?

• Agriculture

• Industry

• Domestic use

• Recreation

Answer explanation

Agriculture is the largest consumer of fresh water, accounting for about 70% of global freshwater use. This is primarily due to irrigation practices needed to grow crops, making it the dominant sector in water consumption.

Tags

NGSS.MS-ESS3-1

What is point source pollution?

• Pollution that can be traced to a specific source

• Pollution that cannot be traced to a specific source

• Pollution from natural sources

• Pollution from agricultural runoff

Answer explanation

Point source pollution refers to contaminants that can be traced back to a specific origin, such as a pipe or a discharge point. This distinguishes it from non-point source pollution, which is diffuse and harder to identify.

Tags

NGSS.MS-ESS3-3

What percentage of Earth's water is fresh water?

• 3%

• 10%

• 20%

• 50%

Answer explanation

Only about 3% of Earth's water is fresh water, while the vast majority, approximately 97%, is salt water found in oceans. Therefore, the correct answer is 3%.

Tags

NGSS.MS-ESS2-4

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

• Rivers

• Lakes

• Icecaps and glaciers

• Swamps

Answer explanation

The majority of Earth's fresh water is found in icecaps and glaciers, which hold about 68.7% of the total fresh water supply. In contrast, rivers, lakes, and swamps contain much smaller proportions.

Tags

NGSS.MS-ESS2-4

NGSS.MS-ESS3-1

Why is it important to conserve fresh water?

• It is the only water humans can safely drink.

• It is abundant and easily accessible.

• It is mostly found in oceans.

• It is not necessary for human survival.

Answer explanation

Conserving fresh water is crucial because it is the only type of water that humans can safely drink. Unlike saltwater found in oceans, fresh water is essential for survival and supports all life forms.

Tags

NGSS.MS-ESS2-4

What is the main reason ocean water is not suitable for drinking?

• It is too cold.

• It contains salt.

• It is too warm.

• It is too shallow.

Answer explanation

Ocean water is not suitable for drinking primarily because it contains salt. High salt content makes it unsafe and unhealthy for human consumption, leading to dehydration and other health issues.

What percentage of Earth's water is not safe to use as drinking water?

• 3%

• 68.7%

• 87%

• 97%

Answer explanation

97% of Earth's water is saltwater or otherwise unsuitable for drinking. Only about 3% is freshwater, and a significant portion of that is trapped in glaciers or underground, making it inaccessible for direct use.

Which city receives its freshwater supply directly from the Hetch Hetchy Aqueduct?

• Fresno

• Los Angeles

• Santa Barbara

• San Francisco

Answer explanation

San Francisco receives its freshwater supply directly from the Hetch Hetchy Aqueduct, which is a key water source for the city, unlike Fresno, Los Angeles, and Santa Barbara.

Water that infiltrates the soil and is stored in the spaces between sediment particles is referred to as:

• water that is evaporated.

• groundwater.

• condensed water.

• water as runoff.

Answer explanation

Water that infiltrates the soil and is stored in the spaces between sediment particles is known as groundwater. This term specifically refers to water found underground, unlike evaporated water or runoff.

Tags

NGSS.MS-ESS2-4