(TEST 2) Earth Science, Lecture pt 5 (ch 11)

Question 1

What is groundwater?

Answer 1

The water beneath the ground surface that is
stored within pores and fractures within the substrate

Question 2

What is a major component of the hydrologic cycle?

Answer 2

Groundwater

Question 3

What is a vital resource used for drinking water, agriculture, and industry?

Answer 3

Groundwater

Question 4

Some precipitation enters the subsurface by

Answer 4

Infiltration

Question 5

Infiltration water adds….?

Answer 5

Soil moisture and groundwater

Question 6

Groundwater often resides in

Answer 6

Subsurface pore spaces

Question 7

What are pores?

Answer 7

Open spaces within any sediment or rock

Question 8

What is porosity?

Answer 8

The total volume of open space within sediment or rock

Question 9

What is permeability?

Answer 9

The ease of water flow due to pore interconnectedness

Question 10

What is hydraulic conductivity?

Answer 10

The ability of water to
move through a material

Question 11

What is an aquifer?

Answer 11

A sediment or rock that can store and transmit water easily

Question 12

What is an aquitard?

Answer 12

Impermeable or low permeability sediment or rock that hinders water flow

Question 13

What are the two types of aquifers?

Answer 13

1. Confined
2. Unconfined

Question 14

What is a confined aquifer?

Answer 14

An aquifer beneath an aquitard or an aquifer sandwiched between two impermeable layers

Question 15

What is an unconfined aquifer?

Answer 15

An aquifer that intersects the surface

Question 16

What type of aquifer is more likely to get polluted?

Answer 16

Unconfined aquitard

Question 17

The water table is a subsurface
boundary where:

Answer 17

Pores are mostly filled with air above the water table and pores are filled with water below the water table

Question 18

What is the unsaturated zone?

Answer 18

Where pores are filled with air above the water table

Question 19

What is the saturated zone?

Answer 19

Where pores are filled with water below the water table

Question 20

How does the water table position change with rainfall?

Answer 20

• During seasonally rainy periods, the water table rises
• During prolonged droughts, the water table falls

Question 21

When do ponds/streams dry up?

Answer 21

When the water table falls below the bottom

Question 22

What do lens-shaped aquitards prevent?

Answer 22

They prevent downward infiltration to the regional water table. Additionally, they lead to a perched water table

Question 23

What is the potentiometric surface?

Answer 23

The elevation to which water in a confined aquifer would rise if a well were sunk into it

Question 24

What do artesian wells do?

Answer 24

They tap into confined tilted aquifers. The water rises to the potentiometric surface without having to be pumped

Question 25

Water distribution system mimics.....?

Answer 25

Artesian aquifers. Water is being pumped to an elevated storage tank

Question 26

In an unsaturated zone, flow moves...

Answer 26

Straight downward

Question 27

In a saturated zone, flow is....

Answer 27

Complicated because it's governed by gravity and pressure

Question 28

Groundwater flow rate is governed by several factors, what are they?

Answer 28

1. Permeability of the porous material 2. The effect of friction between water and conduit walls 3. The spatial change in hydraulic head to hydraulic gradient

Question 29

When do springs occur?

Answer 29

When groundwater discharges at the surface

Question 30

Springs can occur in many forms, what are they?

Answer 30

- Discharge along the side of a hill - Discharge from a solution passageway in limestone - Discharge along faults or fractures in the rock

Question 31

Deep springs tend to be

Answer 31

Saline

Question 32

What is a hot spring

Answer 32

Groundwater discharges of hot water

Question 33

Hot springs waters are usually high in

Answer 33

Dissolved minerals

Question 34

What 2 settings do hot springs develop in?

Answer 34

1. Where deep groundwater surfaces along faults 2. In geothermal regions

Question 35

What is the source of heat in hot springs?

Answer 35

The geothermal gradient

Question 36

High geothermal gradients are linked to

Answer 36

Shallow magma

Question 37

What is cone of depression?

Answer 37

An area lacking groundwater due to the rapid withdrawal by a well

Question 38

What can drawdown cones do?

Answer 38

They can can pull contaminants into a well and reduce flow to nearby streams or springs

Question 39

What is the recharge zone?

Answer 39

An area where water infiltrates downward from surface to groundwater

Question 40

What is the discharge zone?

Answer 40

Area where groundwater is removed from an aquifer, such as a spring, well, river, etc.

Question 41

Groundwater mining is

Answer 41

Groundwater is being used at an unsustainable rate. Pumping rate is higher than the recharge rate

Question 42

What does water in pore spaces hold apart?

Answer 42

Grains

Question 43

Subsidence is mostly

Answer 43

Irreversible

Question 44

Intense pumping in coastal communities can lead to

Answer 44

Saltwater intrusion

Question 45

What happens to pore pressures as water is removed?

Answer 45

They decrease

Question 46

What causes compaction in sediments?

Answer 46

Weight from overlying rocks

Question 47

What is desalination?

Answer 47

The removal of mineral extracts from saline water

Question 48

Distillation is also known as

Answer 48

Reverse osmosis

Question 49

What are some alternative sources to freshwater?

Answer 49

- Reclaimed or recycled wastewater - Aquifer storage and recovery - Rainwater harvesting - Conservation - Xeriscaping - Directed irrigation - Drip irrigation

Question 50

Where does most water contamination come from?

Answer 50

They come from the surface

Question 51

What are some sources that contamination comes from?

Answer 51

- Septic systems - industrial activities - roads - parking lots - older sanitary landfills - waste dumps - agriculture