GROUNDWATER
URL: http:// capp.water.usgs.gov/aquiferBasics/index.html
Chapter 14
Groundwater
14.1: Water in the Ground - Vocabulary
Groundwater:
Porosity:
Permeability:
Water Table:
Spring:
Aquifer:
Artesian Formation:
Geyser:
How does groundwater reach the surface of the earth?
1. Humans can dig into the ground until they reach water, this forms an
ordinary well or they can drill into artesian formations and make
artesian wells
2. Groundwater can flow out as a spring. When cracks occur in the cap
of an artesian formation, artesian or fissure springs can rise up through
the cracks.
3. Groundwater can be heated deep in the Earth or closer to the surface
in areas of recent volcanic activity and can rise to the surface as
boiling hot springs or as a geyser, or in the form of steam in a
fumarole.
Term
Groundwater
Definition
Water that is stored in
the ground
Porosity
The amount of pore
space between the
grains of soil or rock.
The rate at which
liquids pass through the
pore spaces of rock
Permeability
Factors that Affect
Type of rock, soil,
climate topography,
vegetation, land use,
whether land is
saturated.
Particle shape and
sorting
Grain size, whether or
not pores are connected,
presence or absence of
capillary water
Notice in the poorly sorted sediment that there are varying sizes of grains
which make it more difficult for water to be stored in the empty (pore)
spaces. In the well sorted example, the pore spaces are larger and can hold
more water.
The poster is folded into 8.5" x 11" panels; front and back panels can
easily be photocopied.
Permeability
For water to move in an
aquifer, the pores between
rock materials and fractures
in rock must be connected.
If there is a good
connection among pore
spaces and fractures, water
can move freely and we say
that the rock is permeable.
The capacity of rock
material to transmit water is
called permeability. Water
moves through different
materials at different rates faster through gravel,
slower through sand, and
much slower through clay.
Therefore, gravel is more
permeable than sand, which
is more permeable than
clay.
NOTE: The confining cover and confining bed, this means that the top and
bottom of the aquifer are impermeable. In other words, the water is
trapped between the two layers.
THE WATER TABLE
ZONE OF AERATION (ALSO CALLED THE UNSATURATED ZONE)
IS THE AREA ABOVE THE WATER TABLE.
WATER TABLE: THE SURFACE BELOW WHICH THE GROUND IS
SATURATED WITH WATER
ZONE OF SATURATION: THE AREA BELOW THE WATER TABLE
THAT IS SATURATED WITH WATER
Groundwater is stored in the water table
FUMEROLE
14.2 Conserving Ground Water
Vocabulary:
Water Budget:
Recharge:
Surplus:
Usage:
Deficit:
AS WATER IS BEING USED (USAGE), THE
GROUNDWATER SUPPLY GETS LOWER. WHEN THERE IS
NOT ENOUGH RAIN/PRECIPITATION TO RECHARGE
THE WATERTABLE, A DEFICIT OCCURS. WHEN THE
GROUNDWATER IS BEING REPLENISHED OR
RECHARGED, A SURPLUS WILL RESULT.
Subsidence
Subsidence. (See page 306 in your textbook)
Subsidence occurs when groundwater removal causes the ground to become
compacted so much that the ground level drops, or subsides.
14.3 Groundwater and Geology
Vocabulary
Mineral Deposit:
Cavern:
Karst Topography:
karst
topography
Saratoga
Springs, NY
cavern
mineral spring
Mammoth
geyserite
Cave region of
Kentucky
mineral
deposits
stalagmites and
stalactites
1. A region characterized by sinkholes:
karst topography; Mammoth Cave region of Kentucky
2. A spring with a high concentration of mineral matter:
Mineral spring; Saratoga Springs, NY
3. What remains after mineral-containing groundwater
evaporates:
Mineral deposits; geyserite
4. Underground tunnels formed when limestone bedrock
dissolves
Cavern; stalagmites and stalactites
Features of areas with karst topography include: Sinkholes,
sinkhole ponds, lost rivers, underground drainage.
Sinkholes
Sinkholes
Sinkhole in Florida
Sinkhole Ponds
sinkhole pond in the Shenandoah Valley
Lost Rivers
UNDERGROUND DRAINAGE
Mineral Springs
Longmire Mineral Springs
CAVERNS
Natural Bridge Caverns
Luray Caverns
CAVES
Geysers and Gyserites
GEYSER
NOTE: the mineral deposits that have built up at the base of the geyser! That
is the gyserite.
STALACTITES AND STALAGMITES