# AP Environmental Science : General Water Usage

## Example Questions

### Example Question #25 : Water Resources

Approximately what percentage of people in the United States rely on groundwater for their water supplies?

25%

80%

95%

50%

10%

50%

Explanation:

It is estimated that roughly 50% of individuals in the United States rely on groundwater for their water supplies. In some countries this percentage approaches 100%.

### Example Question #2 : General Water Usage

What percent of the world's fresh water use is for agriculture?

Explanation:

Agriculture is by far the largest consumer of the usable fresh water on earth, using up roughly 70% of water consumed by humans.

### Example Question #3 : General Water Usage

Which of the following irrigation methods is most efficient in terms of maximizing water absorbed by plants and minimizing water lost to the system?

Furrow irrigation

Hydroponic irrigation

Flood irrigation

Spray irrigation

Drip irrigation

Hydroponic irrigation

Explanation:

In hydroponics, plants are grown in nutrient-rich water and there is no soil involved in the process. Some water is lost through evaporation, but since it is a closed system, very little water is lost.

### Example Question #26 : Water Resources

Which of the following household activities consumes the most water?

Flushing the toilet

Cooking/Kitchen use

Drinking water

Showering/Bathing

Laundry

Flushing the toilet

Explanation:

Flushing the toilet is the largest contributor to household water consumption, averaging about three gallons of water per flush.

### Example Question #5 : General Water Usage

___________ percent of the Earth's surface is covered by water and the oceans currently contain __________ percent of the Earth's water.

Seventy-five. . . ninety-seven

Seventy-five. . . eighty

Ninety-seven. . . seventy-five

Seventy. . . eighty-five

Seventy-five. . . ninety-seven

Explanation:

Seventy-five percent of Earth's surface is water, and the oceans contain ninety-seven percent of Earth’s water. This means that roughly three percent of the Earth's water resides in rivers, lakes, glaciers, and water vapor.

### Example Question #27 : Water Resources

Curtis owns a cottage on a freshwater lake in the Upper Peninsula. When he goes swimming in the lake, he sticks close to the shallow waters along the shore. In which layer of the lake is Curtis swimming?

Profundal

None of these

Limnetic

Littoral

Benthic

Littoral

Explanation:

The correct response is littoral. The littoral layer is the layer in a freshwater lake along the shoreline with shallow water. The limnetic layer represent "open water", so this layer is off the coastline and in the middle of the freshwater lake. The benthic layer is along the bottom of the lake (i.e. benthic = bottom). And the profundal layer is the layer at the bottom of deep lakes where the light can't reach the bottom.

### Example Question #1 : General Water Usage

Many rivers along the coast will move water from the terrestrial ecosystem into the oceans. What is the region where the river meets the ocean?

Wetlands

Delta

Groundwater

Watershed

Benthic zone

Delta

Explanation:

The correct response is delta. This is the region where a river meets another body of water. It is a transition zone. Important ecological and biological processes occur in delta regions. One good example of a delta is the Nile Delta where the Nile River meets the Mediterranean Sea.

### Example Question #2 : General Water Usage

What is the region where water collects and drains within the landscape?

Delta

Estuary

Watershed

Wetland

Groundwater

Watershed

Explanation:

The correct response is watershed. A watershed is the drainage basin for a particular region. It’s where water collects or drains. It's functions like a funnel. The other answer choices deal with different aspects of water. Estuaries are transition zones between marine and freshwater systems. Deltas are also transition zones where a river dumps sediment into a body of water. And groundwater is not specific to a region - it's just water that is found underneath the soil surface.

### Example Question #3 : General Water Usage

Water is one of the most important resources necessary for sustaining life on Earth. How much of our water by volume is found in the oceans?

97%

75%

99.9%

85%