groundwater

wells

Most groundwater does not flow out of an aquifer as a spring or geyser. So to use the water thats stored in an aquifer people must go after it. How? They dig a well. A well is a hole that is dug or drilled through the ground down to an aquifer. This is illustrated in Figure 13.18. People have depended on water from wells for thousands of years. To bring water to the surface takes energy because the force of gravity must be overcome. Today, many wells use electricity to pump water to the surface. However, in some places, water is still brought to the surface the old-fashioned way with human labor. The well pictured in Figure 13.19 is an example of this type of well. A hand-cranked pulley is used to lift the bucket of water to the surface.

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geysers

Heated groundwater may become trapped in spaces within rocks. Pressure builds up as more water seeps into the spaces. When the pressure becomes great enough, the water bursts out of the ground at a crack or weak spot. This is called a geyser. When the water erupts from the ground, the pressure is released. Then more water collects and the pressure builds up again. This leads to another eruption. Old Faithful is the best-known geyser in the world. You can see a picture of it in Figure 13.17. The geyser erupts faithfully every 90 minutes, day after day. During each eruption, it may release as much as 30,000 liters of water!

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mineral springs and hot springs

Some springs have water that contains minerals. Groundwater dissolves minerals out of the rock as it seeps through the pores. The water in some springs is hot because it is heated by hot magma. Many hot springs are also mineral springs. Thats because hot water can dissolve more minerals than cold water. Grand Prismatic Spring, shown in Figure 13.16, is a hot mineral spring. Dissolved minerals give its water a bright blue color. The edge of the spring is covered with thick orange mats of bacteria. The bacteria use the minerals in the hot water to make food.

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springs and geysers

The top of an aquifer may be high enough in some places to meet the surface of the ground. This often happens on a slope. The water flows out of the ground and creates a spring. A spring may be just a tiny trickle, or it may be a big gush of water. One of the largest springs in the world is Big Spring in Missouri, seen in Figure 13.14. Water flowing out of the ground at a spring may flow downhill and enter a stream. Thats what happens to the water that flows out of Big Spring in Missouri. If the water from a spring cant flow downhill, it may spread out to form a pond or lake instead. Lake George in New York State, which is pictured in Figure 13.15, is a spring-fed lake. The lake basin was carved by a glacier.

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the ogallala aquifer

One of the biggest aquifers in the world is the Ogallala aquifer. As you can see from Figure 13.13, this aquifer lies beneath parts of eight U.S. states. It covers a total area of 451,000 square kilometers (174,000 square miles). In some places, it is less than a meter deep. In other places, it is hundreds of meters deep. The Ogallala aquifer is an important source of freshwater in the American Midwest. This is a major farming area, and much of the water is used to irrigate crops. The water in this aquifer is being used up ten times faster than it is recharged. If this continues, what might happen to the Ogallala aquifer?

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human use of aquifers

Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer.

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aquifer

An underground layer of rock that is saturated with groundwater is called an aquifer. A diagram of an aquifer is shown in Figure 13.12. Aquifers are generally found in porous rock, such as sandstone. Water infiltrates the aquifer from the surface. The water that enters the aquifer is called recharge.

porous and impermeable rock

Water infiltrates the ground because soil and rock are porous. Between the grains are pores, or tiny holes. Since water can move through this rock it is permeable. Eventually, the water reaches a layer of rock that is not porous and so is impermeable. Water stops moving downward when it reaches this layer of rock. Look at the diagram in Figure 13.11. It shows two layers of porous rock. The top layer is not saturated; it is not full of water. The next layer is saturated. The water in this layer has nowhere else to go. It cannot seep any deeper into the ground because the rock below it is impermeable.

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the water table

The top of the saturated rock layer in Figure 13.11 is called the water table. The water table isnt like a real table. It doesnt remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain and lower when the weather is dry.

groundwater

Freshwater below Earths surface is called groundwater. The water infiltrates, or seeps down into, the ground from the surface. How does this happen? And where does the water go?

instructional diagrams

description_image

The picture shows the groundwater and how it moves. Rivers and lakes hold a lot of Earths liquid freshwater. Twenty times more of Earths liquid freshwater is found below the surface than on the surface. Groundwater (or ground water) is the water present beneath Earth's surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from, and eventually flows to, the surface naturally. Natural discharge often occurs at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology.

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This diagram depicts how the groundwater is formed. WIth the diagram, we can understand how the groundwater is formed. First, the water is poured down from the cloud to the earth's surface. The water is recharged to the top layer of the earth called piezometric surface. Below the piezometric surface, the layer containing water is called unconfined aquifer. The top level of the unconfined aquifer is called water table level. Under the unconfined aquifer, there is a layer that the water cannot penetrate. We call the layer as impermeable layer. Under the impermeable layer, a thick layer containing water is called confide aquifer. The earth region that supports the confined aquifer is called confining bed. The hole to obtain water in the unconfined aquifer is called artesian bore.

description_image

This diagram shows the structure of groundwater storage in the earth. The top layer of the earth is call unsaturated zone and does not have water stored. The below the unsaturated zone, there is an unconfined aquifer which contains the water closest to the earth surface. The boundary between the unsaturated zone and unconfined aquifer is called water table. The unconfined water layer absorbers the water from the surface and provide the water to the river or to the ground by a pump. The water circulation period in the unconfined aquifer is from days to years. Under the unconfined aquifer, there is a confining bed. Under the confining bed, there is confined aquifer. This is deeper layer than unconfined aquifer and the water returning cycle to the ground is century long. Under the confined aquifer, there is another confining bed. Below the confined aquifer, there is another confined aquifer. The water returning cycle to the ground is millennium long.

questions

Groundwater usually

a. flows rapidly like an underground river

b. flows uphill or downhill depending on the topography

-->  c. flows very slowly between grains of sediment

d. is stationary in an aquifer

What are the two features of a good aquifer?

-->  a. high porosity and high permeability

b. low porosity and high permeability

c. high porosity and low permeability

d. low porosity and low permeability

During very wet times, the water table will

a. stay the same

-->  b. rise

c. fall

d. hard to know; water tables are not affected by surface conditions.

Water replenishes an aquifer from

a. glacial meltwater

b. rainfall

c. snow melt

-->  d. all of these

Geysers erupt because

-->  a. pressure builds until the water breaks through

b. they have much more water than hot springs

c. the water needs to get downhill in a hurry

d. they are above a volcano that is about to erupt

The water table in an area may rise or fall.

-->  a. true

b. false

An aquifer usually forms in a layer of clay.

a. true

-->  b. false

The rock layer below an aquifer always consists of permeable rock.

a. true

-->  b. false

Water in hot springs is heated by hot magma.

-->  a. true

b. false

Very few land areas have aquifers beneath them.

a. true

-->  b. false

Aquifers are generally found at the same depths.

a. true

-->  b. false

It is impossible for an aquifer to ever run dry.

a. true

-->  b. false

The Ogallala aquifer is one of the biggest aquifers in the world.

-->  a. true

b. false

Land use in an area can affect the amount of water that is available to enter groundwater.

-->  a. true

b. false

Much of the water taken from the Ogallala aquifer is used to irrigate crops.

-->  a. true

b. false

A good aquifer has rock in it that is porous and permeable.

-->  a. true

b. false

The bottom layer of an aquifer has impermeable rock.

-->  a. true

b. false

Many hot springs are also mineral springs.

-->  a. true

b. false

The water table keeps water in an aquifer from seeping deeper underground.

a. true

-->  b. false

Water flows out of a well due to gravity.

a. true

-->  b. false

not having tiny holes that water can pass through

a. aquifer

b. groundwater

c. porous

d. water table

e. well

f. recharge

-->  g. impermeable

underground rock layer that is saturated with water

-->  a. aquifer

b. groundwater

c. porous

d. water table

e. well

f. recharge

g. impermeable

having tiny holes that water can pass through

a. aquifer

b. groundwater

-->  c. porous

d. water table

e. well

f. recharge

g. impermeable

top of an underground rock layer that is saturated with water

a. aquifer

b. groundwater

c. porous

-->  d. water table

e. well

f. recharge

g. impermeable

hole dug or drilled into the ground to reach an aquifer

a. aquifer

b. groundwater

c. porous

d. water table

-->  e. well

f. recharge

g. impermeable

fresh water below Earths surface

a. aquifer

-->  b. groundwater

c. porous

d. water table

e. well

f. recharge

g. impermeable

water that enters an aquifer

a. aquifer

b. groundwater

c. porous

d. water table

e. well

-->  f. recharge

g. impermeable

Water infiltrates the ground where rock is

-->  a. permeable.

b. recharged.

c. saturated.

d. shallow.

The water in an aquifer is more likely to be polluted if the aquifer

-->  a. is close to the surface.

b. does not have a water table.

c. lies below a layer of impermeable rock.

d. is recharged as quickly as water is remove

The Ogallala aquifer is an important source of water in the American

a. Southwest.

b. Northeast.

c. Southeast.

-->  d. Midwest.

Water in a spring comes from a

a. river or stream.

b. lake or pond.

-->  c. layer of rock.

d. none of the above

The majority of Earths liquid fresh water is found in

-->  a. rocks.

b. lakes.

c. rivers.

d. springs.

An aquifer is recharged by

a. a well.

-->  b. surface water.

c. the water table.

d. a spring or geyser.

Rock that holds as much water as possible is said to be

a. recharged.

-->  b. saturated.

c. impermeable.

d. infiltrate

diagram questions

question_image

By what letter is the ASR borehole represented in the diagram?

a. U

b. R

-->  c. P

d. T

question_image

Which Letter represents the injection bubble?

a. F

b. A

c. R

-->  d. W

question_image

Identify M

-->  a. WELL CONTAMINATED WITH SEA WATER

b. MAJOR IRRIGATION WELL

c. NORMAL WATER TABLE

d. LOW WATER TABLE

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Which letter represents the Normal interface?

a. F

b. Y

-->  c. K

d. R

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Which label represents a well contaminated with sea water?

a. J

-->  b. M

c. H

d. X

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What is represented by label N?

a. PERVIOUS STRATA

b. IMPERVIOUS STRATA

-->  c. SATURATION LEVEL

d. ARTESIAN WELL

question_image

Which label shows the Artesian Well?

a. L

-->  b. D

c. K

d. N

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The top of an artesian well is located below which level?

-->  a. N

b. L

c. K

d. D

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Which label represents water?

a. K

-->  b. L

c. D

d. N

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What is the part of the diagram represented with the letter F?

a. CONFINED AQUIFER

b. WATER TABLE WELL

-->  c. FLOWING ARTESIAN WELL

d. UNCONFINED AQUIFER

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Which label shows the artesian well?

a. T

b. K

-->  c. P

d. F

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How is the sun labeled in the diagram?

a. T

b. C

c. U

-->  d. X

question_image

Identify the source of energy in this picture.

a. E

b. R

-->  c. T

d. C

question_image

The process when water infiltrates the ground because soil and rock are porous is called?

a. Evapotranspiration

b. Spring

-->  c. Recharge

d. Discharge

question_image

What comes after evapotranspiration?

a. Watertable

b. Water

c. Spring

-->  d. Rain

question_image

What is the lowest level of the earth depicted?

a. Aquitard

b. Spring

c. Rain

-->  d. Basement

question_image

Which label is used to describe the water that enters the aquifer?

a. confined aquifier

b. watertable

-->  c. recharge

d. unconfined aquifier

question_image

How many actions are labeled?

a. 9

-->  b. 11

c. 7

d. 8

question_image

How many types of aquifiers are there?

a. 1

b. 3

c. 4

-->  d. 2

question_image

Explain how water enters an aquifer.

a. Aquifers are formed by water draining from a lake/wetland.

b. Aquifers are formed by evapotranspiration.

-->  c. Rain falls and the water enters the ground as recharge. It then saturates an underground layer of rock to form an aquifer.

d. Water enters the ground through the watertable to become an aquifer.

question_image

What is a solid rock underlying loose deposits such as soil or alluvium?

a. Shale

b. Rock

c. Seabed

-->  d. Bedrock

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What layer is over the bedrock?

a. Unjoined limestone

-->  b. Shale

c. Sandstone

d. Lake

question_image

How many types of aquifers are present in the diagram?

a. 3

-->  b. 2

c. 1

d. 4

question_image

What happens to the water table during long periods of dry weather?

a. The water table overflows.

-->  b. The water level becomes low.

c. The water level rises.

d. The water level stays the same.

question_image

What layer appears below the shale?

a. Lake

b. Water

c. Glacial

-->  d. Bedrock

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What is the top of a saturated rock layer?

a. Confining bed

b. Unconfined aquifer

c. Confining bed

-->  d. Water table

question_image

What is an aquifer?

-->  a. An underground layer of rock that is saturated with groundwater.

b. An underground layer of rock that is dry

c. a porous layer of sand or rock

d. the top of a saturated rock layer

question_image

What separates all layers of water?

a. Unconfined aquifer

-->  b. Confining bed

c. Water table

d. Confined aquifer

question_image

How many confined aquifers are there?

a. 1

b. 4

-->  c. 2

d. 3

question_image

How many types of area are shown in the picture?

a. 3

b. 7

c. 6

-->  d. 2

question_image

How much more of Earth's freshwater is under the ground rather than above it?

a. ten times

b. thirty times

c. fourty times

-->  d. twenty times

question_image

What is a body of distinctly less permeable material that is located above or below one or more aquifers?

a. Discharge Area

b. Recharge Area

-->  c. Confining Bed

d. Pumped Well

question_image

What is called the level of rock where water is injected for its storage?

a. Injection bubble

b. Supply works

-->  c. Aquifer

d. ASR borehole

question_image

Where is treated water pumped in?

a. lakes

-->  b. supply works

c. storage

d. ground

question_image

How many types of aquifer can be seen in the diagram?

-->  a. 2

b. 5

c. 3

d. 6

question_image

How much aquifiers are depicted in the image?

-->  a. 3

b. 2

c. 1

d. 4

question_image

What is the role of gault clay?

-->  a. Prevents flow between lower greensand and chalk

b. increases flow between lower greensand and chalk

c. supplies water

d. decreases flow between lower greensand and chalk

question_image

Where on the diagram is the aquifer?

a. Major irrigation well

b. Low Water Table

-->  c. Fresh ground aquifer

d. Normal Interface

question_image

Where does the major irrigation well connected to?

a. Sea water

b. Normal Water Table

c. water table

-->  d. Fresh Ground Water

question_image

Where does water go after normal water table?

-->  a. low water table

b. normal interface

c. sea water

d. sea level

question_image

How many parts are there in the diagram?

a. Five

-->  b. Nine

c. Three

d. Eight

question_image

Where is the major irrigation well?

a. in the sea

-->  b. on land

c. beneath water table

d. underground

question_image

Where does the water come from out of the major irrigation well?

-->  a. Fresh ground aquifer

b. Normal Water Table

c. Low Water Table

d. Normal Interface

question_image

Where is the recharge on the graph?

a. aquifer

b. spring

-->  c. the cloud

d. water table

question_image

How many boreholes are there?

a. Four

b. Three

-->  c. Two

d. One

question_image

How many clouds are depicted in the image?

-->  a. 1

b. 3

c. 2

d. 4

question_image

What layer is underneath the aquifer?

a. Unconfined Aquifer

b. Confined Aquifer

c. Water Table

-->  d. Confining Bed

question_image

What does the green layer represent?

a. ground water

-->  b. confining layer

c. artesian well

d. water table

question_image

Where does an aquifer get its water source?

a. Confining Layer

b. Surface Water

-->  c. Aquifer

d. Ground Water

question_image

How many layers are there?

a. Three

-->  b. Five

c. Six

d. Two

question_image

How many trees are shown in the picture?

a. 4

b. 5

-->  c. 2

d. 3

question_image

Where does the water that comes out of the Artesian Well come from?

a. Confining Layer

b. Surface Water

-->  c. Aquifer

d. Ground Water

question_image

Where are the low permeability rocks?

a. Land surface

b. Saturated zone

-->  c. In the ground water

d. Unsaturaded zone

question_image

How many impervious strata are below the artesian well?

a. 4

-->  b. 1

c. 7

d. 5

question_image

How many layers of Pervious Strata are there?

-->  a. One

b. Four

c. Two

d. Five

question_image

What do the trees do to the aquifer?

-->  a. Use the water and discharge it to the atmosphere

b. Take water from the atmosphere and feed it into the aquifer

c. Stabilise the aquifer

d. Confine the water in the aquifer to a particular site

question_image

What separates confined and unconfined aquifers?

a. Very Low hydraulic-conductivity confining bedrock

-->  b. Low hydraulic-conductivity confining unit

c. Unsaturated zone

d. High hydraulic-conductivity confining aquifer

question_image

What is the water below Earths surface?

a. Soft water

-->  b. Groundwater

c. Salt water

d. Distilled water

question_image

What separates a confined and unconfined aquifer?

-->  a. Confining layer

b. Artesian well

c. Water table well

d. Potentiometric surface

question_image

How many wells are there in this image?

a. 5

b. 4

c. 2

-->  d. 3

question_image

What would happen in a drought?

a. The water table level would not change

b. The land would flood

-->  c. The water table level would fall.

d. The water table level would rise

question_image

What is the water that passed through the aquifer called?

a. Precipitation

b. Running water

c. Ground water

-->  d. Recharge

question_image

Between which earth layers would you find groundwater?

a. Basement

b. Soil

c. River

-->  d. Unconfined aquifer, aquitaro, and confined aquifer

question_image

The pump receives water directly from:

a. Basement

b. Soil

c. River

-->  d. Unconfined and confined aquifers

question_image

How many layers does rain water go through before reaching the confined aquifer?

a. 5

b. 4

c. 2

-->  d. 3

question_image

What will happen if there is a steady increase in the amount of rainwater and ground water recharge?

a. The basement will decrease in level

b. The well will dry up

-->  c. The water table will rise

d. The river will dry up

question_image

What is the deepest layer that the artesian wells reach?

-->  a. Aquifer

b. Impermeable bed

c. Impermable cover

d. Spring

question_image

How may clouds are depicted in the image?

a. 3

b. 2

-->  c. 1

d. 4

question_image

What is it called if the water reaches the ground surface under the natural pressure of the aquifer?

-->  a. Artesian Well

b. Spring

c. Impermeable Cover

d. Water-Table

question_image

What does precipitation do for the aquifer?

a. Drains the aquifer

b. Discharges liquid from the aquifer

c. Floods the aquifer

-->  d. Recharges the aquifer

question_image

Where does precipitation lead to in the diagram?

-->  a. River

b. Borehole

c. Sea

d. Bedrock

question_image

How many sources of energy are there?

a. ten

b. two

-->  c. one

d. three

question_image

Where does the energy come from during this process?

-->  a. The Sun

b. Precipitation

c. Weather Station

d. Bedrock

question_image

What happens on heavy rains?

-->  a. Groundwater levels rise

b. Groundwater levels decrease

c. Groundwater levels don't change at all

d. water seeps through saturated ground

question_image

When there's rain, why do the groundwater levels rise?

-->  a. Because water seeps through saturated ground

b. Because the water is absorbed

c. Because water floods to the city

d. The groundwater levels do not rise

question_image

How many stages are there in this groundwater image?

a. 5

-->  b. 4

c. 3

d. 2

question_image

Which layer of the aquifer does the well receive water from?

-->  a. Unconfined Aquifer

b. Clay

c. Confined Aquifer

d. Water Table

question_image

How many aquifers lie beneath the water table?

a. 1

b. 4

c. 2

-->  d. 3

question_image

How many layers of aquifer are there?

-->  a. Three

b. Five

c. Two

d. One

question_image

What happens if there isn't recharge?

a. wells dry up

-->  b. The water table decreases

c. ground water decreases

d. water table stays the same

question_image

Where does the artesian well receive its water?

a. surface water

b. Confining Layer

c. ground water

-->  d. aquifer

question_image

What is the impermeable cover made of?

a. shrubs

-->  b. clay

c. Water

d. rock