Geography Chapter 16

Front 1

Fluvial process

Back 1

-the work of running water on the surface of Earth
-running water encompasses both channeled downslope of surface water and channeled water along a valley bottom

Front 2

Overland flow

Back 2

- Water flowing over the ground surface toward a channel
-un-channeled downslope movement of surface water

Front 3

stream flow

Back 3

-channel movement of water along a valley bottom

Front 4

What are the components of a stream's load? Which part of the stream load carries the most material?

Back 4

-dissolved load, suspended load, bed load
-the bed load carries the most material

Front 5

Interfluves

Back 5

-high terrain located between valleys
-higher land or ridges above the valley that separates adjacent valleys
-drained by overland flow

Front 6

Valley

Back 6

-areas of lower terrain
-stream drainage system is clearly established

Front 7

Rills

Back 7

-very minute channel of water
-formed by water run-off
-break up the sheet flow into tiny channels

Front 8

Gullies

Back 8

-when rills begin to erode into larger channels
-large ditch

Front 9

What does the term “base level” mean?

Back 9

-imaginary surface under continents from sea level at the coast and the lowest level to which land can be eroded

Front 10

Saltation

Back 10

-jumps or bounces
-of material in wind or water

Front 11

Traction

Back 11

-rolling or sliding
-of material in wind or water

Front 12

Stream capacity

Back 12

-the maximum load a stream can transport

Front 13

Stream competence

Back 13

-size of the largest particle that can be transported by a stream

Front 14

If a stream’s velocity doubles, how does that affect its competence? What if the stream’s velocity triples?

Back 14

-if doubled, particles increase four fold
-if tripled, particles incase nine fold

Front 15

How does an oxbow lake form?

Back 15

-cut off meander that fills with water
-a bend on a river course is cut off from the main channel
-Oxbow lakes form when one meander erodes into another, cutting off water to part of the stream channel.

Front 16

Alluvium

Back 16

-a deposit of clay, silt, sand, and gravel left by flowing streams in a river valley or delta, typically producing fertile soil
-any stream deposited sedimentary material

Front 17

What are stream orders?

Back 17

- measure of the relative size of streams
-hierarchy of a drainage network

Front 18

Which stream order is the most numerous on the
landscape?

Back 18

-first order and valleys are more common on landscapes

Front 19

How do higher-order streams form (i.e., how does a second-order stream form from first-order streams)?

Back 19

-when 2 first order stream unite= the second order

Front 20

Splash erosion

Back 20

-raindrops that fall, and are not absorbed by vegetation. They blast the soil particles up and outward

Front 21

Sheet erosion

Back 21

-removal of soil in thin layers by the forces of raindrops and overland flow

Front 22

Describe three ways by which streams are capable of erosion.

Back 22

-Hydraulic action
-Abrasion
-Solution

Front 23

Hydraulic action

Back 23

-The ability of flowing water to dislodge and transport rock particles or sediment

Front 24

Abrasion

Back 24

-a stream's irregular bed is smoothed by the constant friction and scouring impact of rock fragments, gravel, and sediment carried in the water

Front 25

Solution

Back 25

-Rocks susceptible to the chemical weathering process
-acid waters

Front 26

Why does deposition of materials occur in a stream?

Back 26

-because of capacity and competence
-if particles are too heavy, the stream will not have enough energy to carry it, so it will fall to the bottom

Front 27

Ephemeral stream

Back 27

-streams that flow only during and immediately after precipitation

Front 28

Intermittent streams

Back 28

-seasonal stream is one that only flows for part of the year

Front 29

Exotic stream

Back 29

-originates in humid regions but flows through an arid region (Nile)

Front 30

Describe the history and geology of Niagara Falls? Why is the falls further upstream than it used to be in the past?

Back 30

-valley developed first, then moved upstream
-knick point migration
-connects to lake Erie and Ontario
-didn't always have falls
-drainage system
-it is now retreating UPSTREAM
-because of Fluvial erosion

Front 31

How do natural levees form?

Back 31

-cyclic flooding occurs
-water then spills out of a river, carrying solid material
-the material then builds up over time

Front 32

How does stream beheading work?

Back 32

-stream capture
-headward erosion cuts into the drainage of another slower stream
-faster streams cuts off a slower less active stream

Front 33

What factors would increase the erosive effectiveness of stream flow?

Back 33

-streams load

Front 34

What is the largest river in the world that has a delta? What is the largest river in the world that does not have a delta?

Back 34

-Has a Delta: Indus or Ganges
-without a Delta: Amazon

Front 35

What is described by the statement that a stream moves a cubic meter of material past the stream gage every day?

Back 35

-Capacity

Front 36

Bouncing is to sand as suspension is to_____________.

Back 36

-clay

Front 37

Sliding is to gravel as dissolution is to_____________.

Back 37

-ions

Front 38

Which of the following are part of the bed load?

Back 38

-gravel
-sand

Front 39

What is suspended load?

Back 39

-the fine-grained particles that travel in the water column above the stream bed

Front 40

What is the drainage pattern of the streams on Mt. Vesuvius in Italy?

Back 40

-Radial

Front 41

What causes stream capture?

Back 41

-Headward erosion by an adjacent stream with a steeper gradient destroys the drainage divide

Front 42

Why does a delta form?

Back 42

-Stream velocity slows sufficiently that the load is dropped.

Front 43

What is a floodplain?

Back 43

-a flat surface next to a river channel

Front 44

What is a natural levee?

Back 44

-a ridge of flood deposits next to a river channel

Front 45

How does the formation of a natural levee impact flooding?

Back 45

-Natural levees raise the height of the stream channel, reducing the amount of flooding that will occur on the floodplain

Front 46

What type of stream is associated with the formation of an oxbow lake?

Back 46

-meandering stream

Front 47

What is the dominant fluvial process in a clear, sediment-poor stream moving down a steep slope?

Back 47

-downcutting

Front 48

Which processes result in the widening of the floodplain of a meandering stream?

Back 48

-undercutting and lateral erosion

Front 49

Where do deposition and erosion of material occur along a meander?

Back 49

-Deposition occurs on the inside of the meander, whereas erosion occurs on the outside.

Front 50

What is an oxbow lake?

Back 50

-a meander that has been cut off from the original stream channel

Front 51

What is a meander scar?

Back 51

-a landscape feature formed after an oxbow lake dries up

Front 52

Which sequence is correctly ordered from first to last in the development sequence?

Back 52

-Meander, cutoff, oxbow lake, and meander scar

Front 53

When do stream terraces form?

Back 53

-when streams exist under alternating erosional and depositional conditions

Front 54

When do streams erode laterally?

Back 54

-when downcutting is occurring in easy-to-erode sediment or rock

Front 55

What is a stream terrace?

Back 55

-a remnant of an older floodplain that sits above the stream valley

Front 56

How many stream terraces can exist along a single valley?

Back 56

-No limit exists. Stream terraces will keep forming as long as lateral erosion and downcutting continue

Front 57

Are stream terraces depositional or erosional landforms?

Back 57

-Stream terraces can be either depositional or erosional

Front 58

Imagine a valley containing four stream terraces. Where would the youngest stream terrace be found?

Back 58

-the lowest terrace