EARTH SCIENCE
GROUNDWATER
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
An unconfined aquifer:it is not surrounded by impermeable material
|
|
|
An unconfined aquifer:it is surrounded by impermeable material
|
|
|
A confined aquifer:it is surrounded by impermeable material
|
|
|
Both an unconfined and a confined aquifer:both aquifers are collections of water
|
Detailed explanation-1: -Groundwater is fresh water (from rain or melting ice and snow) that soaks into the soil and is stored in the tiny spaces (pores) between rocks and particles of soil. Groundwater accounts for nearly 95 percent of the nation’s fresh water resources.
Detailed explanation-2: -Unconfined aquifers are recharged primarily from precipitation percolating, or infiltrating, down from ground surface. Confined aquifers are generally recharged where the aquifer materials are exposed at the surface (outcrop).
Detailed explanation-3: -Unconfined aquifers are where the rock is directly open at the surface of the ground and groundwater is directly recharged, for example by rainfall or snow melt. Confined aquifers are where thick deposits overly the aquifer and confine it from the Earth’s surface or other rocks.
Detailed explanation-4: -An aquifer is called an unconfined or phreatic aquifer if its upper surface (water level) is accessible to the atmosphere through permeable material. In contrast to a confined aquifer, the groundwater level in an unconfined aquifer does not have a superimposed impermeable rock layer to separate it from the atmosphere.