Groundwater Flashcards
is a valuable natural resource that provides about half of our drinking water and is essential to the vitality of agriculture and industry.
Groundwater
the upper limit o saturation zone
Water Table
Some of the water that soaks in does not
travel far, because it is held by molecular
attraction as a surface film on soil particles
Zone of Soil Moisture
Water that is not held as soil moisture will
percolate downward until it reaches a zone
where all of the open spaces in sediment and
rock are completely filled with water.
Zone of Saturation
- the area above the water table where the
soil, sediment, and rock are not saturated
Unsaturated Zone
Streams may gain water from the inflow of
groundwater through the streambed.
Gaining Stream
Streams may lose water to the groundwater system by
outflow through the streambed.
Losing Stream
a stream gains in some sections and loses in others.
Losing Stream (Disconnected)
which is the percentage of the total volume of rock
or sediment that consists of pore spaces.
Porosity
ability to transmit a fluid
Permeability
Impermeable layers that hinder or prevent water
movement
Aquitards
- Permeable rock strata or sediments that transmit
groundwater freely
Aquifer
is a coefficient that takes into account the permeability of the aquifer and the viscosity of the fluid.
Hydraulic Conductivity
When the water table intersects Earth’s surface, a natural outflow of groundwater results
Spring
a localized zone of saturation called a _________
perched watertable
Often when water is withdrawn from a well,
the water table around the well is lowered.
Drawdown
a depression in the water table,
roughly conical in shape
Cone of Depression
if water rises, sometimes overflowing at the surface
Artisan
aquitards, both above and below the aquifer, must be present to prevent the water from escaping. Such an aquifer is called a
Confined Aquifer
is 6 to 9 °C (11 to 16 °F) warmer than the mean annual air temperature for the localities where they occur
Hot Spring
intermittent hot springs or fountains where
columns of water are ejected with great force at
various intervals
Geysers
- When the water contains dissolved silica deposited around the spring
Silica Sinters or Geyserite
When the water contains dissolved calcium
carbonate deposited around the spring
Calcareous Tufa or Travertine
harnessed by tapping natural underground reservoirs of steam and hot water.
Geothermal Energy
The most spectacular results of groundwater’s erosional handiwork
Caverns
The various dripstone features found in caverns
Speleothems
These icicle-like pendants hang from the ceiling of the cavern
Stalactite
Speleothems that form on the floor of a cavern and reach upward toward the ceiling.
Stalagmite
Joining of stalagmite and stalactite
Column
Karst areas typically have irregular terrain punctuated with many depressions
Sinkhole
is appropriate because the landscape consists of a maze of isolated steep-sided hills that rise abruptly from the ground.
Tower
Hydrosphere
Ocean - % Ice Sheets Groundwater Freshwater lakes Saline Lakes and Inland Sea Soil Moisture Atmosphere Stream Channel
- 2%
- 8%
- 62%
- 009%
- 008%
- 005%
- 001%
- 0001%
When precipitation falls on land, it either soaks into the
ground
Infiltration
some of the water that soaks into the ground is absorbed by plants, which later release it into the atmosphere
Transpiration
involve the transfer of water from the surface directly to
the atmosphere
Evapotranspiration
Runoff initially flows in broad, thin sheets across hillslopes
Sheet Flow
This thin, unconfined flow eventually develops threads of current that form tiny channels
Rills
Rills meet to form gullies, which join to form brooks, creeks, or streams—then, when they reach an undefined size
River
Each drainage basin is bounded by an imaginary line
Divide
area of ground that supplies water to a river system, its
is drained by its rivers and tributaries.
Catchment Area or Drainage Basin
the volume of water flowing in a river in a time period
Discharge
when the supplied water and discharge shows moderate variation throughout the year
Perennial
when the drainage area is small and/or seasonal rainfall will cause high variations in terms of discharge
Ephemeral
when the level of water within the channel is below the channel bank
Low Flow Stage
the stream’s potential to do work or the ability of the stream to erode and transport sediments, it is varied throughout the channel due to frictional resistance.
Flow Velocity
when the level of the water is near or at the channel bank.
High Stage Flow or Bank Full Flow
the deepest part of a channel, the highest velocity, formed when the frictional effect caused by the interaction of your water flow to the floor of your channel
Thalweg
the slope of the stream, expressed as the vertical drop of a stream over a specified distance, varied along the course of the a particular stream
Gradient
refers to the amount of flow in contact other channel with the banks and bed of the channel
Wetted Perimeter
- the removal of blocks from the bed of the channel, aided by fracturing and weathering that loosen the blocks sufficiently so they are moveable during times of high flow rates. It is mainly the result of the impact forces exerted by flowing water
Quarrying
is the process by which the bed and banks of a bedrock channel are ceaselessly bombarded by particles carried into the flow.
Abrasion
are created by the abrasive action of particles swirling in fast-moving eddies and with time produces smooth circular depression.
Potholes
formerly called grand base level by Powell
Ultimate Base Level
Sea Level
downward limit to stream erosion
Base Level
- include lakes, resistant layers of rock, and rivers that act as base levels for their tributaries.
Local or Temporary Base Level
stream’s gradient is steep and the channel is well above base level, down cutting is the dominant activity. Abrasion caused by bed load sliding and rolling along
the bottom and the hydraulic power of fast moving water slowly lower the stream bed
Valley Deepening
graded condition, down cutting becomes less dominant and at this point the stream’s channel takes on a meandering pattern, and more of its energy is directed from side to side
Valley Widening
when rivers have meandering channels that
flow in steep, narrow, bedrock valleys
Incised Meanders
are remnants of a former floodplain are sometimes
present as relatively flat surfaces
Stream Terraces
mineral-rich water dispersed throughout the flow, formed from groundwater percolated through the bedrock and dissolve soluble rocks.
Dissolved Load
load is carried in suspension and is indicated by a muddy appearance as it usually carries fine sand, silt and clay size particles.
Suspended Load
is defined as the speed at which a particle falls through a still fluid
Settling Velocity
carries coarser sediments like coarse sand and gravel size sediments along the surface of the bed by rolling, sliding or saltation.
Bed Load
is the maximum load of solid particles a stream can transport per unit time
Capacity
is a measure of a stream’s ability to transport particles based on size rather than quantity
Competence
form where sediment-charged streams enter the relatively still waters of a lake, an inland sea, or the ocean
Delta
is the general term for sediment deposited by streams
Alluvium
smaller channels that flow away from the main channel when river seeks shorter, higher-gradient routes to base level
Distributaries
meandering rivers tend to build levees parallel to channels, built by years of successive floods
Natural Levees
the region of undrained water behind the natural levee
Back Swamp
streams that often flow kilometers in the back swamp before finding an area to enter the main stream
Yazoo Tributary
fan-shaped deposits that accumulate along steep mountain fronts
Alluvial Fans
are cut into the underlying strata and typically form in the headwaters of river systems where streams
have steep slopes
Bedrock Channel
form in sediment that was previously deposited in the valley
Alluvial Channel
are any stream whose course is controlled by the initial slope of a land surface
Consequent Stream
are not dependent on the original topography. They develop their valleys along an outcrop of less-resistant rocks or a regional fault or joint pattern, at right angles to the drainage consequent upon the slope of the land
Subsequent Stream
develop their valleys on flat-lying sedimentary rocks, or on massive rocks like granite which have no structural features
Insequent Stream
are flows in the same direction as that of the initial consequent stream, but which develops in response to a new base level
Resequent Stream
are streams flowing in the opposite direction of the consequent drainage.
Obsequent Stream
are the result of braided rivers repeatedly change position on the alluvial plain, a broad, extensive region of gravelly bar deposits many times wider than the river
channel
Braid Plains
flow in relatively deep, smooth channels and primarily transport mud (silt and clay), sand, and occasionally fine gravel
Meandering River
at high flow stage, where water may take a short-cut over the top of a point bar and may be recognized in the deposits of a meandering river as a scour that cuts through lateral accretion surfaces
Chute Channel
forms when an abandoned meander loop becomes isolated and the still water will either be filled with deposits through flooding or choked with vegetation
Oxbow lake
- is the process in which the river changes
its position in some way, either by shifting sideways,
as above, or if the channel changes position on the
floodplain
Avulsion
is commonly used for a river or stream in a
desert with ephemeral flow
Wadi
are cones of detritus that form at a break in slope at the edge of an alluvial plain
Alluvial Fan
- larger deposits formed by the lateral migration of a river to produce a cone of detritus
Megafan
Sediment bodies that consist of a mixture of talus deposits and debris-flow deposits, common in subpolar regions where gravity processes are augmented by wet mass flows of debris
Colluvial Fan
funnels the drainage to the basin margin: at this point the valley opens out and there is a change in gradient allowing water and sediment to spread out
Feeder Canyon
is the highest, most proximal point adjacent to the feeder canyon from which the fan form radiates
Fan Apex
is a relatively steep depositional surface and there is a distinct break in slope at the fan toe and may be incised into the fan surface near the apex
Fan-Head Canyon
is the limit of the deposition of coarse detritus at the edge of the alluvial fan
Fan Toe
a viscous slurry of material that spreads out on the fan surface as a lobe It does not travel far and a small, relatively steep, alluvial fan cone is built up if this is the dominant process.
Debris Flow Fan
a rapid, supercritical, turbulent flow that occurs on slopes of about 3 to 5 degrees
Sheetflood Fan
– channelised, in large extent (>4km), with moderate gradient. It resembles fluvial deposits but has
radial variation in clast size and dispersal pattern
Stream Channel Fan
- inland bodies of water, aka inland seas
lake
- forms if the lake is filled to the spill point and there is
a balance of water supply into and out of the
basin. There is a constant supply of water.
Hydrologically Open lake
are perennial, supplied by rivers containing dissolved ions weathered from bedrock and in a climatic setting where there are relatively high rates of evaporation
Saline Lake
is one where the fluvial input is approximately balanced by the loss through evaporation
Balanced Filled
- form if the rate of evaporation exceeds or balances
the rate of water supply there is no outflow
from the lake
Hydrologically Closed Lake
deposits are characterized by accumulation both at the margins, where sediment is supplied to deltas and beaches, and in the deep water from suspension and turbidity currents
Overfilled
are climate dependent on which they can be like freshwater lakes exhibiting thermal stratification on wet and cooler conditions while show sequence of evaporitic depositions in an arid environment
Underfilled
are algae belonging to the Chlorophyta which are seen in many ancient lacustrine sediments in the form of calcareous encrusted stems and spherical
reproductive bodies.
Charophytes
are bright white cherty beds made up of silica
from diatom phytoplankton , deposited cold mountainous or polar environment and are abundant in glacial lakes
Diatomites
