Landforms Chapter 5a & 5b

Which of the following is correct of a floodplain?

It is generally filled with layers of alluvium

Cone-shaped deposits of sediment often found at mouth of canyons in arid and semiarid climates are called

alluvial fans

The entrenchment of a river into its own floodplain produces

alluvial terraces

As they migrate, meandering streams erode their out outside banks, often forming a narrow neck of land that eventually erodes through and forms a _______ and the stream becomes _________.

cutoff; straightener

The suspended load of a stream consists of particles that are

held aloft in the stream flow

Maximum velocity in a meandering stream is

at the outer portion of the meander curve

Faulted and jointed landscapes directs streams courses in patterns of right-angle turns forming this drainage pattern

rectangular

Entrenchment of a channel occurs because

rejuvenation (erosion) occurs due to tectonic uplift

The area of land from which all water in it drains into the same place is known as a(n)

watershed (drainage basin)

________ is the general term for unconsildated clay, silt, sand, gravel, and mineral fragments deposited by running water

Alluvium

Of the world's largest river which has the greatest discharge?

Amazon river

A flood recurrence interval of 100 years means that floods of that size will occur only once every 100 years

False

An alluvial terrace is evidence of aggradation

False

Floodplain formation occurs while a stream is downcutting rapidly

False

Nickpoints migrate downstream

False

A yazoo tributary stream cannot join with the main river in an area because

a natural levee on the main river prevents joining

Which of the following is incorrectly matched?

abrasion-a hydraulic squeeze-and-release action

If the load exceeds a stream's capacity, sediment accumulates in the bed in a process called

aggradation

A cutoff on a meandering stream results in the formation of

an oxbow lake

A meandering stream is one that

is delicately balanced between equilibrium and erosion

The drainage pattern is associated with steep slopes

parallel

The portion of each meandering curve subject to the slowest water velocity undergoes aggradation. This results in a(n)

point bar

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

radial

The drainage pattern results when streams flow off a central peak or dome

radical

A 50-year flood has an annual exceedance probability of

5%

Which of the following best describes the relationship of deforestation to sediment load?

Trees roots help "anchor" soil; as the trees are removed, the soil more readily erodes into the river channels

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

a lake that a river flows into

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

a level below which a stream cannot erode its valley

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

a local, or temporary, base level

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

base level

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

bed load

Excess sediment may result in which of the following channel patterns

braided stream

Processes that are related expressly to streams can transport is its ________ wheras a stream's ability to move particles of specific size is its _________

capacity; competence

The process whereby streams deepen their channel is known as

channel incision (downcutting)

Which of the following is not factored when considering discharge?

chemical length

The sediment load that travels in solution is

dissolved load

Natural levees are created during

floods

Processes that are related are expressly to streams and rivers are termed

fluvial

The downstream portion of a river

generally is of higher velocity, although it is masked by reduced turbulence

The statistical rating of flood discharge is based on

historical records of discharge during precipitation events

This graph, showing the effects of urbanization on streamflow overtime, is an example of a

hydrograph

The science of water and its global circulation, distribution, and properties is known as

hydrology

Bed load is moved by

saltation, traction, and suspension

The ultimate base level is

sea level

Stream transport involves all of the following except

sheet flow

The general term for channelized water flow, regardless of size, is

stream

Which of the following does not favor delta formation?

strong ocean currents

Which of the following will favor stream terrace formation?

tectonic uplift of the headwaters

Stream capture refers to

the process by which one channel erodes through a drainage divide (like a ridge) and captures the headwater regions of another stream

If you live in an area that was flooded by the 100-year flood last year, you can conclude that

there is a 1% chance you could be flooded by the 100-year flood again this year