7.8C Impact of Human Activity on Watersheds

7.8C Impact of Human Activity on Watersheds

Multiple Choice

Fertilizers added to crops on farms can collect in runoff and enter the watershed. This problem would be reduced in areas where -

• crops are grown for animals as well as humans.

• farms are situated on the sides of mountains.

• an extended drought leads to little or no rain.

• the growing season of the crops is longer.

Multiple Choice

When fertilizers enter surface water, they cause problems in the watershed by -

• clogging narrow streams and preventing water from flowing properly.

• increasing the amount of nutrients available to fish in lakes and streams.

• causing rapid algal growth that decrease oxygen levels and choke aquatic life.

• raising the water level in nearby rivers to levels leading to flooding.

Multiple Choice

The use of pesticides and fertilizers is carefully monitored because of the effect they can have on the environment. Which of the following is a possible negative effect of the use of these chemical on the environment?

• These chemicals are expensive to produce.

• Runoff carries these chemicals into lakes and streams.

• Storage space for these chemicals is limited.

• Theses chemicals cannot be purchased in large bulk.

Multiple Choice

Pollutants from a factory that enter the water in a watershed will have a negative effect on which of the following?

• Local pond life

• Rainfall rates

• Direction of river flow

• Available space for crops

Multiple Choice

A neighborhood in a small Texas town had to be evacuated because the houses were sinking due to a problem in the aquifer. What is the most likely cause of this problem?

• Heavy rains caused oversaturation of soil foundations.

• Overbuilding in the area polluted the ground water.

• Runoff from fertilized land created a dead zone. Excessive removal of water weakened the ground.

• Excessive removal of water weakened the ground.