Deck 14: River Systems and Landforms

Question 1

The general term for clay,silt,and sand deposited by running water is

A)alluvium.
B)debris.
C)soil.
D)mud.
E)colluvium

Answer 1

A

Question 2

Which of the following is correctly matched?

A)rills - large,permanent grooves in the land surface
B)drainage divides - ephemeral ridges that develop in the drainage surface
C)Mackenzie River Basin - contained in one province
D)Danube River - an international stream
E)major drainage basin - one river

Answer 2

D

Question 3

When a dam and reservoir are constructed,the natural response of the river and its channel gradient come under the control of

A)the same base level that existed prior to construction.
B)a local,or temporary,base level.
C)the government.
D)an ultimate base level.
E)a calculated base level based on engineering design.

Answer 3

B

Question 4

Watersheds are defined by

A)continental divides.
B)drainage divides.
C)stream orders.
D)fluvial units.
E)ocean basins.

Question 5

Which of the following is incorrectly matched?

A)endogenic processes - initial landscapes
B)exogenic processes - sequential landscapes
C)Mackin - graded river
D)John Wesley Powel - base level concept
E)fluvial - beach systems

Question 6

Which of the following may act as a base level?

A)a lake that a river flows into
B)a benchmark
C)the upper surface of a waterfall
D)the base of the CN Tower
E)the corner of Portage and Main.

Question 7

The ultimate base level is

A)a drainage divide.
B)a dam.
C)sea level.
D)the base of the Rocky Mountains.
E)a watershed.

Question 8

Most of Saskatchewan,Manitoba,and Ontario are in which major drainage basin?

A)Hudson Bay
B)Arctic
C)Missouri
D)Upper Mississippi
E)Pacific

Question 9

The degradation of a landscape by weathering,erosion,and transportation will ultimately reduce the landscape down to

A)base level.
B)continental shelf.
C)the mountain tops.
D)valley level.
E)sea level.

Question 10

When overland flow becomes concentrated on an interfluve,it creates small grooves called ________,which can enlarge to form ________ if erosion of the slope is not controlled.

A)striations potholes
B)potholes striations
C)rills gullies
D)gullies rills
E)striations gullies

Question 11

In response to the occurrence of a local base level,

A)a stream continues to operate to reduce its landscape to sea level-the ultimate base level.
B)sediments accumulate in response to the loss of flow velocity.
C)sea level changes.
D)this situation never occurs in nature.
E)the stream cuts downward.

Question 12

Stream-related processes are termed

A)hydrological.
B)geomorphological.
C)fluvial.
D)erosion.
E)aeolian.

Question 13

At any one moment,approximately ________ of fresh water flows through Earth's rivers and streams.

A)1250 km³
B)13 000 km³
C)104 000 km³
D)22 percent (an amount equal to that in groundwater)
E)542 000 km³

Question 14

The state of Georgia is principally within which major drainage basin?

A)Tennessee
B)Ohio
C)North Atlantic
D)South Atlantic-Gulf
E)Pacific

Question 15

The greatest flow from rivers in North America,east of the continental divide in the Rockies is into the

A)Pacific drainage.
B)Hudson Bay/Arctic drainage.
C)Atlantic drainage.
D)interior West drainage.
E)Gulf of Mexico drainage.

Question 16

Of the world's largest rivers,which has the greatest discharge?

A)Zaire (Congo)River
B)Amazon River
C)Missouri-Ohio-Mississippi river system
D)Chang Chiang (Yangtze)of Asia
E)Nile

Question 17

The high ground that separates one valley from another is known as ________,and it directs surface water runoff known as ________ toward a stream.

A)the maximum contour elevation alluvial discharge
B)the maximum contour elevation sheet flow
C)an interfluve alluvial discharge
D)an interfluve sheet flow
E)the continental divide overland flow

Question 18

Which of the following lists of processes are in the correct sequence as to their occurrence in nature?

A)deposition,erosion,transport,weathering
B)weathering,erosion,deposition,transport
C)weathering,deposition,erosion,transport
D)weathering,erosion,transport,deposition
E)deposition,weathering,erosion,transport

Question 19

Dam decommissioning and removal

A)allows fish habitat to return to a more natural state in many rivers in North America.
B)will increase hydroelectric production.
C)will prevent flooding along major waterways.
D)allows sediment to be collected for removal from ponds.
E)will increase the water temperature in rivers.

Question 20

John Wesley Powell put forward the idea of base level,which refers to

A)an imagined surface that extends inland from sea level,and is inclined gently upward.
B)a level above which a stream cannot erode its valley.
C)an evolutionary cycle of landscape development.
D)flat plateaus.
E)the top surface of a delta.

Question 21

The glaciated shield regions of Canada and northern Europe have disrupted surface drainage patterns that are called ________ patterns.

A)erratic
B)parallel
C)annular
D)deranged
E)trellis

Question 22

Which of the following is correctly matched?

A)abrasion - a hydraulic squeeze-and-release action
B)competence - a stream's ability to move particles of a specific size
C)capacity - the total possible volume of water that a stream can transport
D)fine particles physically held aloft in a stream - dissolved load
E)particles rolled and bounced along a stream bed - suspended load

Question 23

What happens to the flow velocity and erosive power of a stream during a high discharge event if levees have been created to confine flow to the channel? (Remember Q = wdv)

A)velocity increases because the width does not increase,and the erosive power increases.
B)velocity increases because depth does not increase,and the erosive power increases.
C)velocity decreases because the depth of the channel is significantly greater,and the erosive power increases.
D)velocity decreases because the depth of the channel is significantly greater,and the erosive power decreases.
E)there is no change to flow velocity and erosive power as the river is still the same water body.

Question 24

Steep slopes and some relief generally produce which drainage pattern?

A)dendritic
B)deranged
C)parallel
D)annular
E)trellis

Question 25

Stream capture refers to

A)the legal process by which a government secures rights to the waters of a river basin.
B)the merging of two streams flowing in the same valley.
C)the process by which one channel erodes through a drainage divide and captures the headwater regions of another stream.
D)the illegal withdrawal of water from a river.
E)the ponding of water in a river basin after dam construction.

Question 26

The area north of Ottawa on the Canadian Shield in Quebec is characterized by which drainage pattern?

A)deranged
B)trellis
C)parallel
D)rectangular
E)dendritic

Question 27

Stream drainage patterns are determined by which of the following?

A)slope and type of rock
B)volume of water
C)wind speeds in the drainage basin
D)frequency of severe storms
E)average annual temperature

Question 28

As the discharge of a stream increases,which of the following also happens?

A)stream channels narrow,become shallower,and lose velocity.
B)the rate of flow decreases.
C)channel width increases but channel depth decreases.
D)width,depth,and velocity all increase.
E)width and depth increase,but velocity decreases.

Question 29

Sometimes a river will flow through a structural and topographic high,such as a dome.In order for this to occur,what had to happen?

A)people must have created a channel through the feature by blasting,drilling,or tunneling.
B)the river once flowed underground in a cave,but the roof of the cave collapsed and created a surface channel.
C)the river was flowing through the area prior to uplift and the river was able to erode down through the feature as uplift occurred.
D)rivers began flowing from the top of the feature-but on opposite sides.Through time,the rivers eventually joined together as a result of headward erosion,and thereby cut through the structure.
E)a dam was constructed allowing more water to remain in the channel and the river was able to flow over the topography.

Question 30

Rectangular drainage patterns form primarily as a result of

A)differential resistance to erosion.
B)domal uplift.
C)flow through anticlinal and synclinal topography.
D)flow through a faulted landscape.
E)glacial disruption of the landscape.

Question 31

Which of the following channel characteristics adjusts in response to changes in energy of flow and sediment load in the channel?

A)slope,width and depth
B)length,slope and density
C)density,width and sinuosity
D)sinuosity,depth and length
E)density,sinuosity and length

Question 32

Consider the equation Q = wdv.According to the equation,if Q (discharge)remains constant,but w and d decrease (as when a channel becomes more narrow and shallow),the velocity will

A)increase.
B)decrease.
C)remain constant.

Question 33

Which of the following landforms is incorrectly matched with a drainage pattern?

A)volcano - radial
B)folded mountain belt - trellis
C)eroded dome - annular
D)topographically disrupted areas - parallel
E)glaciated topography - rectangular

Question 34

Which drainage pattern is produced by folded topography?

A)radial
B)dendritic
C)deranged
D)trellis
E)parallel

Question 35

Which of the following stream channel types is likely to develop on gently sloping surfaces composed of rocks or sediments with approximately the same resistance to erosion? (Also assume that there are no structural controls on the pattern's development. )

A)radial
B)annular
C)deranged
D)dendritic
E)parallel

Question 36

A squeeze-and-release action works to loosen and lift rocks in a stream channel.This is an example of

A)deposition.
B)hydraulic action.
C)abrasion.
D)suspension.
E)saltation.

Question 37

The flood on the San Juan River in 1941 resulted in

A)erosion followed by redeposition.
B)the river bed falling,then gradually accreting.
C)deposition followed by scouring.
D)changes in water velocity,but no change to the bed.
E)changes in the discharge,but no change to the bed.

Question 38

A central peak,such as a volcanic mountain,generally produces a ________ drainage pattern.

A)radial
B)trellis
C)parallel
D)annular
E)rectangular

Question 39

The lengths of the individual channels in a dendritic drainage pattern are ________ and this increases energy ________.

A)minimized efficiency
B)minimized inefficiency
C)maximized efficiency
D)maximized inefficiency

Question 40

Drainage density refers to

A)the thickness of the water in the stream.
B)the number of channels in an area.
C)a measure determined by dividing the length of all the channels by the area of its drainage basin.
D)the arrangement of channels in a given area.
E)the volume of water in the drainage basin.

Question 41

As a stream's velocity decreases,which of the following sizes of sediments will be deposited last?

A)cobble
B)gravel
C)sand
D)silt
E)clay

Question 42

If you followed a river from its headwaters downstream to the ocean,you would observe the water clarity decrease because

A)the saltation load would increase.
B)the amount of clay due to weathering increases as does the load and influx of sediment into the river.
C)there is little bed load transport in the mountains.
D)suspended and solution load are greatest in the mountains and decrease as the river enters less steep territory.
E)all material settles out of the flow toward the river mouth and biotic activity increases,increasing the water clarity.

Question 43

A low-velocity flow over a smooth stream bed produces a

A)turbulent flow.
B)churning action.
C)laminar flow of individual particles.
D)extreme traction.
E)stream erosion.

Question 44

An increase in turbulence

A)results in deposition of sediment.
B)results in aggradation.
C)causes terraces to form.
D)increases the river's erosive power.
E)decreases the size of the particles the stream is able to move.

Question 45

Which of the following rock types is most affected by fluvial solution?

A)granite
B)sandstone
C)rhyolite
D)limestone
E)marble

Question 46

If the capacity of a stream is exceeded,________ will occur.

A)downcutting
B)erosion of valley walls
C)aggradation
D)channel switching
E)abrasion

Question 47

The construction of a dam across a river is likely to cause ________ upstream and ________ downstream.

A)erosion aggradation
B)erosion erosion
C)aggradation erosion
D)aggradation aggradation

Question 48

Bed load is moved by

A)saltation and traction
B)traction and suspension.
C)suspension and solution.
D)traction and solution.
E)saltation only.

Question 49

Which of the following tends to occur when an area experiences tectonic uplift in its headwater region?

A)the stream will begin to deposit more of its load.
B)the amount of turbulence will decrease.
C)the channel will begin to erode downward at a faster rate.
D)the channel will begin to aggrade.
E)a braided stream will develop.

Question 50

Which of the following stream channel forms is likely to develop when aggradation greatly exceeds erosion?

A)V-shaped valleys
B)braided channels
C)meandering channels
D)straight,steep-walled channels
E)deeply incised canyons

Question 51

The total possible load a stream can transport is its ________,whereas a stream's ability to move particles of specific size is its ________.

A)capacity competence
B)competence capacity
C)discharge competence
D)bed load sediment load
E)competence turbulence

Question 52

The downstream portion of a river

A)generally becomes more sluggish.
B)generally is of higher velocity,although it is masked by reduced turbulence.
C)features greater hydraulic action than do upstream portions.
D)has lower discharges than do upstream portions.
E)meanders as a result of the system operating to expend the most effort.

Question 53

Braided streams are characterized by

A)sediment deposition in the channel resulting in the formation of sand and gravel bars and numerous small "channels."
B)a small load in relation to its discharge.
C)severe erosion of the channel bed.
D)ice blocks and very cold water.
E)an abundance of vegetation.

Question 54

As you journey from the headwaters of the Mackenzie to the Beaufort Sea,you would observe the load decrease in size from boulders to sand and silt due to the process of

A)solution.
B)abrasion.
C)hydraulic action.
D)suspension.
E)frost action

Question 55

The suspended load of a stream consists of particles that are

A)rolled and bounced along the stream bed.
B)held aloft in the stream flow.
C)dragged along the stream bed.
D)dissolved in solution.
E)attached to the bed.

Question 56

As base level is approached by a stream,the ability of a stream to erode its bed

A)increases.
B)decreases.
C)remains constant.

Question 57

Increased velocity and a rough channel can produce a

A)turbulent flow.
B)laminar flow.
C)maximum velocity.
D)decreased capacity.
E)extreme traction.

Question 58

Which of the following terms is used for a type of stream transport?

A)saltation.
B)discharge.
C)abrasion.
D)sheet flow.
E)overland flow.

Question 59

Braided streams,such as the Brahmaputra River,are found in areas

A)where the load is lower than the capacity.
B)where the bed and suspended loads are low.
C)that are subject to new sediment from glaciers or landslides.
D)subject to sediment erosion from the river bed.
E)with solid rock or resistant channel walls.

Question 60

The largest material that can be carried by a stream is carried as

A)bed load.
B)suspended load.
C)dissolved load.
D)truck load.
E)volumetric load.

Question 61

Which of the following is likely to occur if the gradient of a stream increases? (Assume that the discharge and sediment load remain unchanged. )

A)the stream will begin to deposit more of its load.
B)the amount of aggradation in the channel will increase.
C)the amount of bed load transport will decrease.
D)the stream will begin to erode its channel and/or its banks.
E)the stream will stabilize.

Question 62

Which of the following is true of the longitudinal profile of most rivers?

A)it always changes at a constant rate from the headwater region to the sea.
B)it is convex in shape.
C)it is concave in shape.
D)it is gentle upstream and steep downstream.
E)it has a length to width ratio of 5:1

Question 63

Which is typical of a rejuvenated system?

A)entrenched meanders and terraces
B)oxbow lakes and downcutting
C)decreased downcutting
D)terraces and point bars
E)point bars and meander scars

Question 64

Which of the following is correctly matched?

A)cut bank - inner portion of a stream meander
B)point bar - area of substantial erosion
C)aggradation - sediment accumulation in the stream channel
D)braided stream - single,sinuous channel
E)pool - shallowest part of the channel

Question 65

Which of the following refers to the time frame in which equilibrium conditions exist?

A)geologic
B)graded
C)steady
D)equi-time
E)chaotic

Question 66

If you wanted to build a structure on a river bank-especially one that flows through unconsolidated sediments-you should build the structure ________ to maximize its lifetime.

A)along the cutbank
B)above the point bar
C)in a delta
D)next to a pool
E)downstream from the riffle

Question 67

A cutoff on a meandering stream results in the formation of

A)an oxbow lake.
B)a levee.
C)a point bar.
D)a terrace.
E)a braided stream.

Question 68

A tributary that is physically unable to join the main channel on a floodplain is called a

A)alluvial stream.
B)yazoo tributary.
C)levee tributary.
D)meandering tributary.
E)offset stream

Question 69

Entrenchment of a channel occurs because

A)a decrease in stream gradient occurs.
B)a change in the bed load size-distribution occurs.
C)the river flows from consolidated rock into a region composed of loose sediments.
D)rejuvenation occurs due to uplift.
E)isostatic downwarping of the crust occurs.

Question 70

Which of the following is true of floodplains?

A)they rarely occur in a fluvial landscape.
B)they are erosional landforms.
C)they often evolve after a stream has ceased downcutting at a significant rate.
D)they are the areas of a stream where terraces are present.
E)they interrupt the stream profile.

Question 71

A meandering stream is one that is

A)completely stable.
B)completely unstable.
C)delicately balanced between equilibrium and chaos.
D)closed in terms of energy and matter input.
E)closed in terms of energy,but open with respect to matter input.

Question 72

A stream becomes graded when

A)erosion and deposition are in equilibrium.
B)a local base level controls the stream.
C)a river achieves a longitudinal stream profile of a steeper upstream portion.
D)its basin becomes rejuvenated.
E)water supply is diminished.

Question 73

Floodplains

A)are erosional features located within a depositional feature.
B)are associated with surface erosion.
C)are generally filled with layers of alluvium.
D)are covered by a surface layer of coarse material including cobbles and gravel.
E)prevent aggradation of the river.

Question 74

Which of the following is correct regarding floodplains?

A)they are formed by a flood in the area adjacent to the stream.
B)natural levees on either side of a stream are formed during times when the stream is at flood stage and overflows the bank.
C)they are generally high elevation areas.
D)they are characterized by rapids and low waterfalls.
E)they interrupt the stream profile

Question 75

Which of the following is a feature of a rejuvenated landscape?

A)entrenched meanders
B)the Mississippi River delta
C)a broad,nearly level floodplain
D)point bars and cut banks
E)pools and riffles

Question 76

Natural levees are created

A)during floods.
B)during normal flow conditions.
C)during low flow conditions.
D)as the river discharge decreases.
E)when the carrying capacity of the stream is limited.

Question 77

Maximum velocity in a stream is found

A)near the bottom.
B)near the inside of a meander.
C)at the center and near the surface,corresponding with the deepest parts of the stream channel.
D)at the center and near the surface,corresponding with the shallowest parts of the stream channel.
E)in the geometric centre of the channel.

Question 78

The average size of sediment in a natural levee is ________ that found in the surrounding floodplain.

A)larger than
B)smaller than
C)the same size as

Question 79

An interruption in a stream's graded profile of equilibrium is called a

A)gradation.
B)longitudinal interruption.
C)base level.
D)nickpoint.
E)riffle

Question 80

If a stream has just the gradient and discharge to transport its sediment load,it is said to be

A)"fit."
B)competent.
C)graded.
D)in a nonequilibrium state.
E)chaotic