Science Watershed

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.

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

• increasing the amount of nutrients available to fish in lakes and streams.
• 
  clogging narrow streams and preventing water from flowing properly.
• raising the water level in nearby rivers to levels leading to flooding.
• causing rapid algal growth that decrease oxygen levels and choke aquatic life.

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

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.

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?

• 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.

A paper company wants to build a paper mill in the watershed where a village exists. In order to minimize potential pollution to the village, which of the following
locations is the best to build the mill?

• Nearest to the main street of the village
• Closest to a freshwater stream or river
• Downstream from the village
• At the highest point in the watershed

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

Subsidence, or the sinking of the ground because of
weakened underground rock layers, is often the result of
humans -

• fertilizing crops with strong chemicals.
• building dams to change the direction rivers flow.
• excessively pumping water from aquifers.
• 
  constructing highways through natural habitats.

Overflow during a heavy rainstorm from a wastewater treatment plant would result in -

• 
  over-treated drinking water.
• 
  flooding in the local aquifer.
• polluted runoff into nearby ponds.
• weakened housing foundations.

Runoff from agricultural land carries chemicals from fertilizers that collect in a lake. The buildup of chemicals can eventually cause -

• rainfall levels to drop causing drought and a shorter growing season.
• river tributaries to reroute, changing the flow of natural waterways.
• 
  aquatic life, such as fish and turtles, to die from a lack of oxygen.
• excess water to fill the aquifer, resulting in pore shrinkage and subsidence.