Deck 15: River Systems

Question 1

Stream drainage patterns are determined by which of the following?

A)Regional steepness and relief.
B)Variations in rock resistance.
C)Climate.
D)Climate,regional steepness and relief,and variations in rock resistance

Answer 1

D

Question 2

Which determines drainage density?

A)Dividing the number of streams in a basin by the basin area.
B)Dividing the actual path length of a stream by the shortest path length of the stream.
C)Averaging the discharge values across a drainage basin.
D)Dividing the total length of all stream channels in the basin by the area of the basin.

Answer 2

D

Question 3

Which is a drainage divide that separates drainage basins that empty into different bodies of water surrounding a continent?

A)Catchments.
B)Deltas.
C)Continental divides.
D)Interfluves.

Answer 3

C

Question 4

By which are watersheds defined?

A)Continental divides.
B)Drainage divides.
C)Stream orders.
D)Fluvial units.

Question 5

Which is a drainage system that maintains its original course and pattern as it erodes into underlying horizontal beds of different structure than that in which the system evolved?

A)Deranged pattern.
B)Discordant streams.
C)Annular patterns.
D)Superposed stream.

Question 6

A central peak,such as a volcanic mountain,generally produces which drainage pattern?

A)Radial.
B)Trellis.
C)Parallel.
D)Annular.

Question 7

Which primarily results in rectangular drainage patterns?

A)Differential resistance to erosion.
B)Domal uplift.
C)Flow through anticlinal and synclinal topography.
D)Flow through a faulted landscape.

Question 8

Which is known as the science of water and its global circulation,distribution,and properties?

A)Geomorphology.
B)Climatology.
C)Lithology.
D)Hydrology.

Question 9

Steep slopes and some relief generally produce which drainage pattern?

A)Dendritic.
B)Deranged.
C)Parallel.
D)Annular.

Question 10

Drainage basins are which type of systems?

A)Open.
B)Closed.
C)Open in terms of energy,closed in terms of matter.
D)Closed in terms of energy,open in terms of matter.

Question 11

Which is the high ground that separates one valley from another and directs sheetflow?

A)The maximum contour elevation.
B)Drainage divide.
C)An interfluve.
D)The continental divide.

Question 12

Which are processes that are related expressly to streams and rivers?

A)Fluvial.
B)Geomorphic.
C)Lemnetic.
D)Lotic.

Question 13

Which refers to drainage density?

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.

Question 14

Which is the general term for channelized water flow,regardless of size?

A)River.
B)Gully.
C)Stream.
D)Rill.

Question 15

Which is the area of land from which all water drains into the same place?

A)Interfluve.
B)Watershed.
C)Drainage divide.
D)Fluvial units.

Question 16

Which are the small,ephemeral grooves into which overland flow can concentrate?

A)Striations.
B)Potholes.
C)Rills.
D)Gullies.

Question 17

Which is the tree-like drainage pattern that efficiently moves water and sediment through its system due to minimization of the total length of each branch?

A)Dendritic.
B)Trellis.
C)Radial.
D)Deranged.

Question 18

Which is defined as a basin in which water leaves via evapotranspiration or subsurface gravitational flow instead of reaching the ocean?

A)A disappearing stream.
B)Sheetflow.
C)A closed system.
D)Internal drainage.

Question 19

What is the drainage density of a 100 km2 drainage basin with 25 km of stream,running through three rivers?

A)3)
B)33.333.
C)4 km • km-2.
D)0)25 km • km-2.

Question 20

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

A)Zaire (Congo)River.
B)Amazon River.
C)Saint Lawrence River.
D)Chang Chiang (Yangtze)of Asia.

Question 21

Which is the drop in stream elevation per unit distance?

A)Discharge.
B)Base level.
C)Gradient.
D)Aspect.

Question 22

Which is the drainage pattern that is associated with steep slopes?

A)Parallel.
B)Dendritic.
C)Trellis.
D)Deranged.

Question 23

Which is a tributary that is physically unable to join the main channel on a floodplain due to natural levees?

A)Alluvial stream.
B)Yazoo tributary.
C)Levee tributary.
D)Meandering tributary.

Question 24

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

A)Volcano - annular.
B)Folded mountain belt - trellis.
C)Eroded dome - radial.
D)Topographically disrupted areas - parallel.

Question 25

Which is the drainage pattern associated with faulted and jointed landscapes that direct stream courses in patterns of right-angle turns?

A)Radial.
B)Rectangular.
C)Trellis.
D)Dendritic.

Question 26

Which is the drainage pattern that results when streams flow off a central peak or dome?

A)Annular.
B)Trellis.
C)Radial.
D)Rectangular.

Question 27

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.

Question 28

Which of the following is used to measure streamflow?

A)Stilling well and staff gauge.
B)Barometer and sling psychrometer.
C)Statistical methods of probability.
D)Reservoirs.

Question 29

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

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.

Question 30

Which is the effect of urbanization on a typical stream hydrograph?

A)Urbanization creates a base flow.
B)Urbanization increases lag time between storm peak and peak stream discharge.
C)Urbanization decreases runoff.
D)Urbanization decreases lag time between storm peak and peak stream discharge.

Question 31

Consider a mass of water above base level in a stream as it flows downstream.Contrast the energy when the water is above base level with the energy when it flows downstream.Which lists the correct pairing of stream energy?

A)Kinetic; potential.
B)Potential; kinetic.
C)Kinetic; kinetic.
D)Potential; potential.

Question 32

Which of the following is factored when considering discharge?

A)Channel length,channel width,channel depth.
B)Channel width,channel depth,water velocity.
C)Channel depth,water velocity,channel length.
D)Water velocity,channel length,channel width.

Question 33

Which is the ultimate base level?

A)A drainage divide.
B)A dam.
C)Sea level.
D)Dependent on the geological substrate.

Question 34

With no clear geometry and no true stream valley,which drainage pattern occurs in areas such as glaciated shield regions?

A)Deranged.
B)Radial.
C)Parallel.
D)Dendritic.

Question 35

Which is the drainage pattern that is characteristic of dipping or folded topography?

A)Annular.
B)Trellis.
C)Radial.
D)Rectangular.

Question 36

Structural domes with concentric patterns of rock strata guide stream courses to form which drainage pattern?

A)Radial.
B)Parallel.
C)Annular.
D)Dendritic.

Question 37

Which of the following may act as a local base level?

A)A lake that a river flows into.
B)A drainage divide.
C)The upper surface of a waterfall.
D)An interfluve.

Question 38

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

A)Deposition.
B)Hydraulic action.
C)Abrasion.
D)Suspension.

Question 39

John Wesley Powell put forward the idea of base level.To which does this refer?

A)The amount of discharge in a particular reach of a stream.
B)A level below which a stream cannot erode its valley.
C)An evolutionary cycle of landscape development from fluvial action.
D)The average height of a stream channel.

Question 40

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

A)Base level.
B)Continental shelf.
C)The mountain tops.
D)Valley level.

Question 41

Stream piracy refers to which of the following?

A)The legal process by which a state 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.

Question 42

Bed load is moved by

A)Saltation and traction.
B)Traction and solution.
C)Suspension and solution.
D)Saltation and suspension.

Question 43

If the load exceeds a stream's capacity,sediment accumulates in the bed? Which is this process?

A)Downcutting.
B)Degradation.
C)Aggradation.
D)Saltation.

Question 44

Which process is the main process contributing material in solution in sediment load?

A)Physical weathering.
B)Chemical weathering.
C)Biological weathering.
D)Erosion.

Question 45

Channels with gradual slopes often develop a sinuous form called which pattern?

A)Braided stream.
B)Anabranching stream.
C)Meandering stream.
D)Straight stream.

Question 46

Which best describes a meandering stream?

A)A stream that is completely stable.
B)A stream that is completely unstable.
C)A stream that is delicately balanced between equilibrium and chaos.
D)A stream that is closed in terms of energy and matter input.

Question 47

The portion of each meandering curve subject to the fastest water velocity undergoes the greatest erosive action.What does this action form?

A)Meander scar.
B)Oxbow.
C)Cutbank.
D)Point bar.

Question 48

Where are braided streams found?

A)In areas where the load is higher than the capacity.
B)In bedrock-controlled channels.
C)In low-gradient streams carrying sediment that has been transported far from its source.
D)In locations dominated by sediment erosion on the river bed.

Question 49

Stream transport involves which of the following?

A)Saltation,bed load,traction.
B)Bed load,traction,sheet flow.
C)Traction,sheet flow,saltation.
D)Sheet flow,saltation,bed load.

Question 50

Which best describes the particles in the suspended load of a stream?

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

Question 51

Where is maximum velocity in a straight channel 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.

Question 52

As they migrate,meandering streams erode their out outside banks,often forming a narrow neck of land that eventually erodes through and forms a cutoff.Which of the following does the stream then become?

A)Narrower.
B)Straighter.
C)More sinuous.
D)Wider.

Question 53

Where is maximum velocity in a meandering stream?

A)Near the bottom.
B)At the inner portion of the meander curve.
C)At the center and near the surface.
D)At the outer portion of the meander curve.

Question 54

Which is the sediment load consisting of fine-grained clastic particles held aloft in the stream?

A)Bed load.
B)Suspended load.
C)Dissolved load.
D)Flow load.

Question 55

Excess sediment may result in which of the following channel patterns?

A)V-shaped valleys.
B)Braided stream.
C)Meandering stream.
D)Straight,steep-walled channels.

Question 56

The sediment load consisting of coarse material too large to remain in suspension,moving along the channel bottom via traction and saltation is which load?

A)Bed load.
B)Suspended load.
C)Dissolved load.
D)Flow load.

Question 57

Which is the sediment load that travels in solution?

A)Bed load.
B)Suspended load.
C)Dissolved load.
D)Flow load.

Question 58

Which are large river systems that have multiple large channels across a vast floodplain?

A)Anabranching rivers.
B)Braided streams.
C)Meandering streams.
D)Steep-walled channels.

Question 59

The portion of each meandering curve subject to the slowest water velocity undergoes aggradation.This results in which of the following?

A)Meander scar.
B)Oxbow.
C)Cutbank.
D)Point bar.

Question 60

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

A)Bed load.
B)Suspended load.
C)Dissolved load.
D)Flow load.

Question 61

When are natural levees created?

A)During floods.
B)During normal flow conditions.
C)During low flow conditions.
D)During degradation.

Question 62

A cutoff on a meandering stream results in the formation of which of the following?

A)An oxbow lake.
B)A levee.
C)A point bar.
D)A terrace.

Question 63

Which is a stream that downcuts at the same rate as tectonic uplift,thereby maintaining its course?

A)Meandering stream.
B)Anabranching river.
C)Antecedent stream.
D)Rejuvenated river.

Question 64

Which is an interruption in a stream's graded profile of equilibrium?

A)Gradation.
B)Longitudinal interruption.
C)Base level.
D)Nickpoint.

Question 65

What prevents a yazoo tributary stream from joining with the main river in an area?

A)The yazoo flows in a different valley.
B)A small structural ridge separates the rivers.
C)A natural levee on the main river prevents joining.
D)An anthropogenic flow control structure keeps the rivers separate.

Question 66

Which of the following is correct regarding floodplains?

A)They are formed by aggrading channels depositing sediment in the stream channel.
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 steep sloping areas.
D)They are characterized by rapids and low waterfalls.

Question 67

Why does entrenchment of a channel occur?

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

Question 68

A flood plain is best described by which of the following?

A)It is an erosional feature located within a depositional feature.
B)Floodplains are not associated with deposition.
C)It is generally filled with layers of alluvium.
D)Despite the name,they are rarely subjected to flooding.

Question 69

How does the average size of sediment in a natural levee is compare to that found in the surrounding floodplain?

A)Larger than.
B)Smaller than.
C)The same size as.

Question 70

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

A)Gravel.
B)Sand.
C)Silt.
D)Clay.

Question 71

When does a stream become graded?

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

Question 72

The entrenchment of a river into its own floodplain produces which of the following?

A)Backswamps.
B)Alluvial terraces.
C)Natural levees.
D)River deltas.

Question 73

Which is a stream that maintains an equilibrium between the processes of erosion and deposition and,therefore degradation and aggradation?

A)Graded stream.
B)Oxbow.
C)Anabranching river.
D)Meandering stream.

Question 74

Which is the general term for unconsolidated clay,silt,sand,gravel,and mineral fragments deposited by running water?

A)Alluvium.
B)Deposition.
C)Aggradation.
D)Degradation.

Question 75

Which of the following best describes floodplains?

A)They rarely occur in a fluvial landscape created by an "old" river.
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.

Question 76

Which is typical of a rejuvenated system?

A)Entrenched meanders,oxbow lakes,increased downcutting.
B)Oxbow lakes,increased downcutting,terraces.
C)Terraces,entrenched meanders,oxbow lakes.
D)Entrenched meanders,increased downcutting,and terraces.

Question 77

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.

Question 78

Which of the following is correct 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.

Question 79

Which of the following is correctly matched?

A)Cutbank - maze of interconnected channels.
B)Point bar - area of substantial erosion.
C)Aggradation - sediment accumulation in the stream channel.
D)Braided stream - outer portion of a stream meander.

Question 80

Which is a meander that becomes isolated from the rest of the river?

A)Oxbow lake.
B)Undercut bank.
C)Point bar.
D)Cutoff.