Explain the importance of groundwater as a source of freshwater

Groundwater is an important source of freshwater, partly because it accounts for approximately 30% of the Earth's freshwater. Groundwater is an important source of freshwater for areas that do not have access to other sources of freshwater, such as areas that are experiencing droughts.

What approximate percentage of the Earth's freshwater is groundwater?
a.
10%
b.
20%
c.
30%
d.
40%

c. 30%

Explain how groundwater overdraft occurs and its likely consequences.

Groundwater overdraft occurs when the groundwater resources are used up more quickly than they are replenished. Groundwater overdraft can occur for a period of time without noticeable consequences, but eventually the aquifer will not be able to keep up with the rate of use as its water storage is depleted. This leads to unproductive or even dried up wells.

Groundwater overdraft occurs when _______.
a.
the location of the water table changes due to season
b.
aquifers become polluted
c.
the rate of use exceeds the rate of replenishment
d.
trees are planted

c. the rate of use exceeds the rate of replenishment

Why has groundwater use increased over time?

The principal reason for the increase of groundwater use is the increasing population. Urbanization and pollution have both contributed to an increase in the use of groundwater. Polluted rivers, lakes, and springs are no longer viable sources of groundwater. Urbanization has concentrated large populations in areas that might not have direct access to surface water or that might have a larger demand for freshwater than surface water can supply.

Which of the following is not a source of groundwater pollution?
a.
landfills
b.
septic tanks
c.
smoke stacks
d.
fertilizer

c. smoke stacks

Compare the use of groundwater in preindustrial times to industrial times.

Groundwater was used in preindustrial times, but was less widely used than in industrial times. With urbanization and increasing populations, the use of groundwater increased in industrial times to meet the increased demands for freshwater. People in preindustrial times were more likely to settle near sources of surface water.

Aquifers are _______.
a.
located below the water table
b.
important sources of freshwater
c.
located in the saturated zone
d.
all of the above

d. all of the above

What are some ways that groundwater is used in the United States currently?

Groundwater is used for drinking, irrigation, mining, industry, and recreation.

Human use of groundwater has _______ over time.
a.
increased
b.
decreased
c.
decreased and then increased
d.
remained the same

a. increased