Deck 13: Freshwater: Streams, Lakes, and Groundwater

Question 1

The competence of a mountain river is ___________ than that of a river on a floodplain because ___________ .

A)lower; the gradient is greater
B)higher; the gradient is greater
C)lower; there are more boulders
D)higher; there is more water

Answer 1

B

Question 2

Why are artificial levees only useful for some flooding events?

A)Levees cannot be built larger than the surrounding floodplain.
B) Flash floods occur too quickly for officials to close the levees.
C) Levees are built in rural areas and will not help for flooding in the city.
D)Large floods can create high pressures and undermine the levee.

Answer 2

D

Question 3

The distinction between a valley and a canyon is

A)nonexistent; the two terms are synonymous.
B)that the sides of a canyon are more steep than those of a valley.
C)that the sides of a valley are more steep than those of a canyon.
D)that valleys are often cut by streams, whereas canyons are eroded by the wind.

Answer 3

B

Question 4

Lakes are bodies of standing water, but not all lakes contain freshwater. Why are some lakes fated to become salt lakes?

A)They have only inlets but no outlets.
B)They have both an inlet and outlet.
C)They have neither an inlet nor an outlet.
D)There are no salt lakes.

Question 5

When one stream captures the flow from another stream it is called

A) stream rejuvenation.
B) stream piracy.
C)antecedent capture.
D)beveled capture.

Question 6

Why do meandering rivers meander (move) across their floodplain?

A)The large amounts of sediments that choke the rivers create point bars that are easily eroded away by additional flow of the rivers.
B)They carry very small amounts of sediment and thus are not slowed down as a result of friction between the sediment and the river bottom.
C)They are curved, which causes erosion on one side of the curve and deposition on the other side of the curve, thus moving the river in the direction of erosion.
D)Sediment is constantly being deposited on the river bottom, which causes the river to overflow its banks and create a new channel.

Question 7

Ephemeral streams

A)consist of a series of intertwined channels that are overloaded with sediment.
B)have flowing water either episodically or during only a portion of the year.
C)have a channel that is highly sinuous (curvy).
D)are those that divert flow from streams they have intersected through stream erosion.

Question 8

The discharge of a river will increase if

A)the water in the river slows down.
B)it rains in the drainage basin area.
C)the area does not receive rain for a while.
D)sediments settle to the bottom of the river.

Question 9

A small mountain stream will have a ___________ competence and a __________ capacity than the Mississippi River.

A)lower; lower
B)lower; greater
C)greater; greater
D)greater; lower

Question 10

The discharge of a river traveling through a temperate region will typically ____________ downstream; the discharge of a river traveling through an arid region will typically ____________ downstream.

A)increase; increase
B)decrease; decrease
C)increase; decrease
D)decrease; increase

Question 11

In uniform sediments with a relatively constant and gentle slope at the surface, a ___________ drainage network is expected.

A)dendritic
B)radial
C)rectangular
D)trellis

Question 12

The base level of a tributary would become ___________ if a dam and a reservoir were constructed where it flowed into a trunk stream.

A)lower
B)slower
C)faster
D)higher

Question 13

Ultimately, the base level of a stream valley can be no lower than the

A)average elevation of the continent on which it is found.
B)average elevation of the sea.
C)average elevation of the local catchment.
D)maximum elevation of the local catchment.

Question 14

Within a meander, where is sediment most likely to be deposited?

A)on the outer banks of the meander
B)on the inner banks of the meander
C)uniformly to either side of themeander
D)directly in the middle of the meander

Question 15

Braided streams

A)consist of a series of intertwined channels that are overloaded with sediment.
B)have flowing water either episodically or during only a portion of the year.
C)have a channel that is highly sinuous (curvy).
D)are those that divert flow from streams they have intersected through stream erosion.

Question 16

Ephemeral streams, as opposed to permanent streams,

A)are subject to erosion of sediment.
B)contain water only during rainfall.
C)can be fed by large drainage basins.
D)occur only in tropical regions.

Question 17

A meander that is cut off to become completely isolated from the main channel but which retains water is a(n)

A)meander neck.
B)cut bank.
C)oxbow lake.
D)thalweg.

Question 18

The figure below shows an example of a ___________ drainage network.

A)dendritic
B)radial
C)rectangular
D)trellis

Question 19

What physical property of the underlying rock would lead to the formation of a cliff over which a waterfall may form?

A)a high resistance to erosion
B)high porosity
C)large permeability
D)very fine grain sizes

Question 20

One way to mitigate flooding is to build ___________ , which are areas that are intended to flood and as such are not zoned for buildings.

A) floodways
B) floodplains
C)peneplains
D)artificial levees

Question 21

Land subsidence is likely when

A)groundwater recharge occurs.
B)the calcium content of groundwater increases.
C)the water table rises.
D)discharge lowers the water table.

Question 22

Ultimately geysers erupt because of the

A)periodic opening and closing of a fracture.
B)mixing of hot and cold water to form steam.
C)decrease in pressure as water rises.
D)increase in pressure from the hot water.

Question 23

Recharge areas for artesian wells and springs are generally in the

A)desert.
B)mountains.
C)ocean.
D)flatlands.

Question 24

For a well to function properly, it must be drilled below the water table and into a(n)

A)aquifer.
B)aquitard.
C)spring.
D)geyser.

Question 25

The elevation of the water table

A)is a constant for a given area so long as the topography remains the same.
B)may rise during times of drought and sink during rainy periods.
C)may rise during rainy periods and sink during droughts.
D)is completely unpredictable.

Question 26

During a particularly cold winter in Florida, the temperatures remained below freezing for several weeks. To avoid freeze damage to the crops, farmers used well water to continuously spray the crops and maintain a protective coating of ice around the crops. Shortly after this long cold snap, sinkholes began forming throughout the region. Were these events linked?

A)No; watering crops does not cause the formation of sinkholes.
B)No; sinkholes form in a karst landscape, on which farmers cannot farm.
C)Yes; the farmers removed too much water from the aquifers and induced subsidence.
D)Yes; the farmers added too much weight to the surface and induced subsidence.

Question 27

A relatively impermeable layer of rock or sediment is termed a(n) ___________ in hydrogeologic contexts.

A)aquitard
B)confined aquifer
C)unconfined aquifer
D)unsaturated zone

Question 28

How do geologists distinguish between a natural lake and a reservoir?

A)Reservoirs can become a natural lake over time.
B)Natural lakes can provide areas on recreational activities but a reservoir cannot.
C)Natural lakes are where Earth's surface is relatively higher and can provide surface runoff.
D)Reservoirs are lakes that have been trapped by the construction of a dam or retaining wall.

Question 29

A periodic explosive eruption of steam and water from within the ground up through the surface is termed a(n)

A) artesian well.
B) geyser.
C)spring.
D)recharge area.

Question 30

A person is digging a hole, when the hole suddenly starts to fill with water. What have they found?

A)the capillary zone
B)the vadose zone
C)the water table
D)an aquitard

Question 31

What does it mean if the water table of a potential spring does NOT reach above the ground surface?

A)The aquifer does not have any recharge into it and thus is dry.
B)There will never be any artesian wells or springs associated with the aquifer.
C)It will not be possible to pull water out of the aquifer from any type of well.
D)The aquifer does not have a high enough permeability to produce water.

Question 32

Where would you expect to find geysers?

A)Iceland
B)England
C)Antarctica
D)Greenland

Question 33

When one stream captures the flow from another stream, it is called

A)stream rejuvenation.
B)stream piracy.
C)antecedent capture.
D)beveled capture.

Question 34

Pumping vast quantities of water locally

A)raises the local water table.
B)lowers the local water table, forming a cone-shaped depression.
C)lowers the local water table, forming a cylindrical depression.
D)does not affect the water table.

Question 35

Lakes can form

A)when soil becomes supersaturated.
B)during hurricane activity.
C)because of a collapsed volcanic caldera or subsidence caused by rifting.
D)as a result of the deposition of valley walls or subsidence caused by convergence.

Question 36

Permeable rock or sediment between the water table and the land surface represents a(n)

A) aquitard.
B) confined aquifer.
C)unconfined aquifer.
D)unsaturated zone.

Question 37

A person is drilling and finds water. They would know they have found a perched aquifer if the water

A)table is too high.
B)table is too low.
C)is saltier.
D)is contaminated

Question 38

A flowing artesian well is one that

A)discharges groundwater at the ground surface without pumping.
B) has its intake sited within the vadose zone of an unconfined aquifer.
C) has its intake sited within the unsaturated zone of an unconfined aquifer.
D)has its recharge area at an elevation below sea level.

Question 39

Rates of groundwater flow are ___________ than stream flow because the water __________

A)higher; can flow through large caverns
B)higher; does not have any obstacles to overcome
C)lower; contains dissolved ions that slow it down
D)lower; must make its way through tiny pore spaces

Question 40

Hot groundwater is mineralized because

A)minerals cannot precipitate in hot water.
B)the hot water dissolves minerals.
C)cold water cannot dissolve minerals.
D)it runs through layers containing salts.

Question 41

Urbanization causes an increase in the volume of water entering a stream because of the abundance of ___________ surfaces in cities and towns.

A)permeable
B)impermeable
C)porous
D)potable

Question 42

Consider a water well that can be drilled in either a shallow, unconfined aquifer or a deep, confined aquifer. Drilling deeper will cost more money; however, the choice is made to drill into the confined aquifer. This is because the confined aquifer will

A)most likely have a higher water quality.
B)most likely have a higher permeability.
C)not be subject to overpumping.
D)contain more water.

Question 43

Building dams on rivers traps sediment behind the dams. This sediment would normally have traveled all the way down the river and out into the ocean. How might this sediment starvation affect the coastal beaches?

Question 44

What will happen to a stream if the local base level is increased, for example, by adding a dam to the river?

Question 45

Topography dominated by depressions formed by the collapse of caves is termed a

A)valley and ridge province.
B)karst landscape.
C)horst and graben landscape.
D)speleothem formation.

Question 46

Karst terrain forms in areas that are covered in which type of rock?

A)basalt
B)sandstone
C)limestone
D)mudstone

Question 47

What are porosity and permeability, and how do they affect the rate of groundwater flow?

Question 48

If a dam is built on a river, what effects might be felt downstream?

A)increase in the fish population
B)decrease in sediment supply
C)increase in the sediment load
D)increase in flood potential

Question 49

The groundwater quality of an aquifer is tested and found to have high amounts of arsenic. It is likely that the arsenic

A)comes from the dissolved minerals in the aquifer rock.
B)comes from the reaction of the water with the testing supplies.
C)is being poured into the groundwater to poison the town.
D)is not actually there; it does not show up in groundwater.

Question 50

List and describe one possible effect from overpumping.

Question 51

What is a stream? How is it similar to and different from a river or a creek?

Question 52

In many areas with karst terrain, people use sinkholes as places to dump garbage. What effect might this practice have on the groundwater supply?

A)None; sinkholes are not connected to groundwater sources.
B)It clogs the sinkholes so that water cannot percolate into the groundwater.
C)It could block the groundwater discharge from unconfined aquifers only.
D)It could contaminate the groundwater in any or all aquifers in the area.

Question 53

The images below are of two different geologic scenarios in which springs could form. Describe the similarities and differences between these two scenarios.
A

Question 54

Label the three zones that water moves through as it percolates into Earth on the image below. Also indicate the location of the water table.

Question 55

Extra sediment can be released into rivers by ____________ , whereas ___________ cause(s) a decrease in the sediment supply downriver.

A)dams; urbanization
B)farms; urbanization
C)dams; farms
D)farms; dams

Question 56

If a large airport, complete with paved runways, parking lots, and many new structures, is built next to a river, what might the effect be?

A)The fish population will decrease.
B)The nutrient supply for fish will be diminished.
C)There will be an increased likelihood of flooding.
D) Overuse of water will dry out the river.

Question 57

A geologist is trying to determine the discharge of a river. The stream is semicircular in shape with a width of 10 m. They measure the velocity of the river to be 0.2 m/s. What is the discharge of the river? Show your work.

Question 58

Name and describe two methods to mitigate flood hazards.

Question 59

If someone were to dump chemicals into a dry river, such as the one shown below, those chemicals would

A)evaporate into the atmosphere and no longer be a danger.
B)remain in the soil but would not make it into the groundwater.
C)seep into the groundwater but flow away from the city's wells.
D)end up flowing with the groundwater toward the city's wells.

Question 60

Explain how caves are formed, making sure to include the name of the acid involved and how it forms.