Deck 10: Streams and Floods

Question 1

A cutoff meander can become an oxbow lake.

Answer 1

True

Question 2

An alluvial fan is a fan- or cone-shaped pile of sediment that forms where a stream emerges from a narrow mountain canyon.

Answer 2

True

Question 3

Stream discharge is one of the most important factors that controls stream velocity.

Answer 3

False

Question 4

Drainage basins are bowl-shaped depressions with a lake in the middle, and all streams in the basin discharge their water and sediment into that lake.

Question 5

The process of deepening a valley by erosion of the streambed is called downcutting.

Question 6

A stream can lengthen its valley by headward erosion.

Question 7

Stream-dominated river deltas, like the Mississippi, display the characteristic triangular shape of a delta.

Question 8

A bar in a river channel is a ridge of sediment, usually sand and gravel, deposited in the middle or along the banks of a stream.

Question 9

Paved areas and storm sewers decrease the rate of surface runoff of water.

Question 10

Braided streams flow in a network of interconnected rivulets around numerous bars.

Question 11

A stream reaches its maximum velocity close to the shoreline.

Question 12

Saltation of sand grains begins when they are dissolved.

Question 13

Point bars are sandbars deposited in the middle of river channels.

Question 14

Stream erosion and deposition are controlled primarily by a river's velocity.

Question 15

A trellis stream pattern consists of parallel main streams with short tributaries meeting them at right angles.

Question 16

Low stream velocity generally results in erosion and transportation of sediment.

Question 17

Hydraulic action refers to the ability of flowing water to pick up and move rock and sediment.

Question 18

The interrelationship of the hydrosphere, geosphere, biosphere, and atmosphere is visualized through the hydrogeologic cycle.

Question 19

Sheetwash is a thin layer of unchanneled water flowing downhill.

Question 20

The discharge of a stream is the volume of water that passes a given point in unit of time (for example, 50 cubic meters per second).

Question 21

The limit to downcutting of a stream is called the ___ level.

A) head
B) base
C) flow
D) stream
E) foot

Question 22

A(n) ___ stream flows in a network of rivulets (subchannels) around numerous sandbars.

A) braided
B) meandering
C) incised
D) channelized
E) rilled

Question 23

A stream's discharge is __.

A) the volume of dissolved mineral matter carried by the stream in a unit of time
B) the volume of solid sediment carried by the stream in a unit of time
C) the volume of water passing through a specific point along the stream in a unit of time.
D) the volume of excess water during flood stage
E) the average amount of water in the entire stream system

Question 24

_____ are low ridges of flood deposited sediment that form on either side of a stream channel and thin away from the channel.

A) Point bars
B) Natural levees
C) Incised meanders
D) Deltas
E) Oxbow lakes

Question 25

A _____ is a ridge of sediment built by sedimentation on the middle or banks of a stream channel.

A) levee
B) flood plain
C) meander loop
D) channel
E) bar

Question 26

Rivers may develop pronounced sinuous (wiggly) curves called a ___ pattern.

A) braided
B) meandering
C) incised
D) channelized
E) rilled

Question 27

A ridge or strip of ground separating one drainage basin from another is termed a ____.

A) delta
B) neck
C) crest
D) plateau
E) divide

Question 28

Movement of cobbles and boulders by rolling, sliding, or dragging in a streambed is called ____ load.

A) dissolution
B) solution
C) suspension
D) traction
E) saltation

Question 29

A(n) __ is the body of sediment deposited at the mouth of a river when the river's velocity decreases.

A) apron
B) alluvial fan
C) bar
D) delta
E) wart

Question 30

________ are low ridges of flood-deposited sediment that form on both sides of a stream channel and thin away from the channel.

A) Point bars
B) Natural levees
C) Oxbows
D) Cut banks
E) Deltas

Question 31

Certain features on the planet Mars resemble _____ on Earth.

A) river channels
B) hydrologic cycle
C) alluvial fans
D) deltas
E) placer deposits

Question 32

In North America, the ___ separates streams that flow into the Pacific Ocean from those that flow into the Atlantic Ocean and Gulf of Mexico.

A) Appalachian Mountain Range
B) Mississippi River
C) Continental Transect
D) Sierra Nevada Mountain Range
E) Continental Divide

Question 33

The ______ is the total area drained by a river and its tributaries.

A) flow area
B) divide
C) drainage basin
D) domain
E) hood

Question 34

A "100-year flood" has a _______ percent chance of occurring in any given year.

A) 1
B) 100
C) 10
D) 0.1
E) 0.01

Question 35

The gravel bed load of a stream moves by _____.

A) dissolution
B) solution
C) suspension
D) sliding and rolling
E) flotation

Question 36

A stream can increase its length by _____.

A) building a delta
B) meandering
C) headward erosion
D) All of the answers are correct.

Question 37

A cutoff meander may become a crescent-shaped __.

A) kettle lake
B) moraine lake
C) levee lake
D) oxbow lake
E) Yazoo lake

Question 38

A ____ drainage pattern is one in which streams diverge outward likes spokes on a wheel.

A) jointed
B) tilted
C) compass
D) radial
E) conical

Question 39

___ influences the velocity of a river along with gradient.

A) Direction of flow
B) Channel shape and roughness
C) Temperature of the water
D) Chemistry of the water
E) Latitude of the river

Question 40

The movement and interchange of water between the sea, air and land can be visualized by the ____.

A) longitudinal profile of a stream
B) channelization procedures
C) hydrologic cycle
D) hydrosphere interactions such as precipitation
E) solar radiation

Question 41

A stream can lengthen itself by ____.

A) headward erosion
B) deposition of a delta
C) meander-loop cut-off
D) stream discharge
E) Headward erosion and deposition of a delta are both correct, but meander-loop cut-off and stream discharge are incorrect.

Question 42

Deltas may be river dominated, tide dominated or _____.

A) tsunami dominated
B) wave dominated
C) glacier dominated
D) wind dominated
E) plate tectonic dominated

Question 43

___ beds form the main body of a delta with angles of inclination up to 20 to 35 degrees in small sandy deltas.

A) Turbidite
B) Foreset
C) Backset
D) Bottomset
E) Topset

Question 44

A river's velocity is faster ____.

A) along the inside of a meander loop near the point bar
B) along the center line of the stream channel, exactly halfway between point bar and cut bank
C) along the outside of a meander loop near the cut bank
D) at the water's surface, in contact with the atmosphere
E) along the channel bed at the very deepest part of the channel

Question 45

Discharge is the product of average stream width times average stream depth times ___.

A) stream velocity
B) stream sinuosity
C) stream elevation
D) stream gradient
E) stream temperature

Question 46

On large alluvial fans, the _____ sediment is deposited near the mountains.

A) finest
B) clay
C) coarsest
D) quartz
E) best sorted

Question 47

A graded stream can be deepening its channel by down cutting while part of its energy is also widening its valley by ______ erosion.

A) downward
B) longitudinal
C) lateral
D) distal
E) proximal

Question 48

The process of deepening of a valley by erosion of a streambed is called __.

A) lateral erosion
B) down cutting
C) faulting
D) aggradation
E) subsidence

Question 49

Floods are described by ____, the average time between floods of a given size.

A) discharge
B) forecasting
C) calendar year
D) recurrence interval
E) lunar month

Question 50

A(n) ___ drainage pattern of a river resembles a tree.

A) dendritic
B) trellis
C) bush
D) arbor
E) leaf

Question 51

The ______ load is sediment light enough to remain lifted indefinitely above the bottom by water turbulence.

A) dissolution
B) solution
C) saltation
D) suspension
E) segregation

Question 52

_____ meanders are meanders that retain their sinuous pattern as they cut vertically downward below the level at which they originally formed.

A) Incised
B) Excised
C) Excavated
D) Concentrated
E) Superposed

Question 53

The delta of the ______ River is a wave-dominated delta that resembles the Greek letter delta and is the origin of the name.

A) Mississippi
B) Nile
C) Amazon
D) Colorado
E) Ganges

Question 54

___ is/are sudden localized floods of large volume and short duration, often triggered by heavy rainstorms.

A) Sheetwash
B) Dry flooding
C) Flash floods
D) Channel erosion
E) Stream piracy

Question 55

_____ refers to sand grain movement in a series of short leaps or bounces off the bottom.

A) Jumping
B) Floating
C) Saltation
D) Hopping
E) Vaulting

Question 56

_______ deposits are found in streams where running water has mechanically concentrated heavy sediment such as gold.

A) Placer
B) Lag
C) Granular
D) Pebble
E) Agglomerated

Question 57

A(n) ___ is a step-like landform found above a stream and its floodplain. It is a remnant of an older flood plain or river-eroded flat surface.

A) levee
B) incised meander
C) cut bank
D) stream terrace
E) upland plateau

Question 58

Streams erode rock and sediment by ___.

A) hydraulic action
B) solution
C) abrasion
D) All answers are correct.
E) None of the answers are correct.

Question 59

Flood control structures along the Mississippi River surrounding New Orleans are predominantly _____.

A) upstream dams
B) riprap lining
C) bypasses
D) artificial levees
E) All of the answers are correct.

Question 60

A(n) ____ stream is one that exhibits a delicate balance between its transporting capacity and the sediment load available to it.

A) graded
B) ephemeral
C) consequent
D) incised
E) beheaded