Watersheds

Humans affect watersheds and wetlands by :

• polluting
• destroying
• overbuilding
• all of the above

A ___________________ is the area of land that collects runoff and channels it into a main river.

• rill
• gully
• stream channel
• watershed

Where is water most likely to become contaminated?

• forest
• near a cattle farm
• near a dam
• at the bottom of the ocean

Which of the following is an example of how humans can reduce the rate of natural erosion?

• plow cropland
• clear land of trees to build
• plant trees
• logging

What is erosion?

• When rocks and sand are moved by water
• When water gets contaminated
• When plants grow next to a river
• When rocks are broken apart by water

Which of the following can pollute water?

• Moss
• Pesticides
• Seaweed
• Fish

The use of pesticides and fertilizers must be 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 chemicals on the environment?

• Runoff carries these chemicals into lakes and streams.
• Theses chemicals cannot be purchased in large bulk.
• 
  These chemicals are expensive to produce.
  
• Storage space for these chemicals is limited.

The illustration provided shows a river and four cities on that river. When the water from the river was sampled at location X, it was determined to be polluted with various chemicals. What would be the most likely source for this pollution?

• City 1 and City 2
• City 2 and City 3
• City 3 and City 4
• City 1 and City 4

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

• 
  Available space for crops
• Local pond life
• Rainfall rates
• Direction of river flow

Waste from animals can contaminate water.

• True
• False