Hydrology

Which is most likely the largest contributor to a decrease in North Carolina’s water availability?

• evaporation
• global warming
• increase in population
• expansion of agricultural areas

Which would a scientist expect to find in a lake that experienced a sudden increase in nitrate levels?

• an increase in temperature
• an increased number of fish
• an increase in dissolved oxygen
• an increased amount of algae and aquatic plants

The Water Quality Act of 1965 directs each state to adopt its own water quality standards. The Clean Water Act of 1972 established standards that applied to all bodies of water in the United States. Which of the following describes as advantage of a nationwide approach to water protection? 

• both state and federal agencies would be needed to enforce standards
• some states would be required to enforce standards lower than their own
• states would be less involved in deciding the levels of chemicals to allow in water
• companies operating in different states would need to meet only one set of standards

Justin is a farmer who wants to improve the quality of the local streams on his farm. Which action will have the most impact?

• growing cotton instead of corn
• using a tractor with smaller wheels
• increasing the amount of fertilizer used on the crops
• planting a vegetative buffer strip along the perimeter of the field

Which best explains why water may be treated differently in different communities?

• some communities avoid using groundwater
• groundwater requires more expensive treatments
• environmental factors vary between communities
• because the communities make a vote

Where is most of Earth’s water found?

• lakes
• oceans
• streams
• aquifers

Which best explains why so little of the water on Earth is available for human use?

• 97% of total water on Earth is freshwater, and most of the remaining 3% is salt water in the ocean basins.
• 97% of total water on Earth is salt water, and most of the remaining 3% is freshwater frozen in ice caps and glaciers.
• 97% of total water on Earth is freshwater, and most of the remaining 3% is salt water found in underground aquifers.
• 97% of total water on Earth is salt water, and most of the remaining 3% is freshwater found in lakes, rivers, and ponds.

Which best explains why freshwater is in such short supply?

• Most of the freshwater is frozen in ice sheets.
• Most of the freshwater is trapped underground.
• Most of the freshwater is cycling in the atmosphere.
• Most of the freshwater is in the bodies of plants and animals.

Which would best demonstrate water movement within the water cycle?

• lakes
• streams
• river basins
• oceans

Why is freshwater in short supply on Earth? 

• Most of it is frozen.
• Most of it is polluted.
• Most of it is in the atmosphere.
• Most of it is trapped underground.