Stream Processes

Question 1

What is another term for Stream Processes?

Answer 1

Fluvial Processes

Question 2

What is a stream?

Answer 2

Any area of channeled water flow

Question 3

What is Sheet Flow?

Answer 3

over-land flow (spread out, even depth)

Question 4

What is Stream Flow?

Answer 4

concentrated flow into a direct channel

Question 5

What are Fluvial Processes?

Answer 5

a stream’s ability to shape a landscape, depending on CAPACITY and COMPETENCY

Question 6

Define Capacity

Answer 6

total amount of material that the stream can move *depends on discharge- volume of water moving out.
Higher discharge = higher capacity

Question 7

Define Competency

Answer 7

the size of material that can be carried by the stream
*depends on stream velocity.
Higher velocity = higher competency
Arises from kinetic energy- stream flow converts potential energy into kinetic energy (movement)

Question 8

What is the Stream Gradient?

Answer 8

Stream Steepness, related to kinetic energy

Gradient = Steepness

Question 9

What is the Base Level?

Answer 9

Level below which a stream cannot erode its valley
Ultimate base level = the ocean
Local base level = a local limit to erosion, such as a lake or resistant rock layer

Question 10

Describe Stream Energy

Answer 10

Ability of a stream to erode and transport materials is dependent on its total amount of energy.
-Influenced by velocity, volume of water.
Energy used for erosion is not available for transportation and vice-verse

Question 11

What is Stream Erosion?

Answer 11

Hydraulic action (movement of materials through pressure and shearing force) + Abrasion (mechanical erosion of stream bed by waters or solids in the stream)
-occurs with both stream and sheet flow

Question 12

What are the 3 types of stream transportation?

Answer 12

Solution Load
Suspended Load
Bed Load

Question 13

Solution Load

Answer 13

Material dissolved and carried in stream (usually through chemical weathering)
“Kool-Aid” - dissolved throughout

Question 14

Suspended Load

Answer 14

Small, clastic particles held aloft in water, with the energy of the water keeping them suspsended

• carried along in water, without contacting the stream bed
• more energy, more suspended load
• Kinetic Energy

Question 15

Bed Load

Answer 15

Material pushed along the bottom by the water’s energy (rolling, bouncing along the bottom of the stream)
Saltation: skip/bounce
Traction: sliding along the bottom

Question 16

Describe Deposition

Answer 16

Occurs when stream energy is no longer sufficient to transport load, results in sorting based on sizes.
-dramatic decrease in energy
-deposits/dumps material
(largest things drop first)

Question 17

Braided rivers

Answer 17

river split into different channels (multiple, interwoven)

-more materials than the stream has the capacity to transport

Question 18

Meandering Streams

Answer 18

The river’s form changes as undercuts and point bars migrate (curves = meanders)
-outside of the river has more energy at turns, inside is moving slower)
Inside = deposition

Question 19

Where do deltas form?

Answer 19

At the end of streams

Question 20

What are Nickpoints?

Answer 20

Hard rock on top of softer rock

Question 21

What are graded streams?

Answer 21

Graded streams have reached a balance between erosion, transportation and deposition
-when uplift occurs, streams can return to active periods of down cutting.