Chapter 14 Quiz - Groundwater
A perched water table develops when ________.
a horizontal aquitard above the regional water table lies below an aquifer
An aquifer is ________.
a permeable rock unit that possesses a saturated zone
An unconfined water table is the ________.
boundary between the unsaturated zone above and saturated zone below
Which of the following describes the configuration of an unconfined water table around a pumping well?
cone of depression
The most useful aquifers for obtaining abundant groundwater possess _____.
high porosity and high permeability
The unsaturated zone of an aquifer ________.
lies above the water table
Which of the following geologic materials would have the highest groundwater velocities and be least effective in removing unwanted pollutants from the water?
limestone; numerous solution channels and fractures widened by dissolution
________ describes the ease of fluid transmission through rock.
permeability
Which of the following can possibly contaminate an aquifer?
pesticides. industrial chemicals. sewage.
________ is the percentage of a rock or unconsolidated sediment that consists of empty space.
porosity
A ________ is the icicle-like speleothem that grows down from the roof of a cavern.
stalactite
Excessive groundwater withdrawals can cause ________.
the water table to fall
In areas underlain by unconsolidated or weakly consolidated strata, lowering of the water table can cause the land to subside.
true
In areas with humid climate, the water table of an unconfined aquifer generally slopes downward towards stream valleys.
true
In general, contaminated groundwater will be naturally cleaned faster by circulation through porous and permeable sands than by circulation through fractured, crystalline igneous and metamorphic rocks.
true
Most caves and caverns originate by dissolution of limestone.
true
The water table is a surface separating the saturated and unsaturated zones.
true
Water-saturated muds have low permeabilities but can have greater porosities than well-cemented sandstone.
true
An artesian well is one in which ________.
water rises above the top of the aquifer without any pumping
Which of the following best describes how geysers erupt?
with a slight reduction in pressure, water in a saturated, natural conduit suddenly boils, sending a plume of steam and hot water into the air above the vent
