Rivers

Question 1

Surficial Processes

Answer 1

• erosion
• transportation
• deposition on the Earth’s surface (or near surface)
  Landscapes are constantly created and destroyed

Question 2

Agents of Surficial Processes

Answer 2

• running water (streams and drainage systems)
  – groundwater
  – glaciers
  – gravity (mass wasting)
  – wind

Question 3

Streams and Drainage Systems

Answer 3

Stream any flowing body of water, regardless of size.
River a major branch of a large stream system
Channel the stream passage way
Discharge the quantity of water passing a given point
Load the sediment carried by the stream

Question 4

Stream Loads and Sediment Movement

Answer 4

• Solution load (dissolved material)
• Suspended load (silt and clay)
• Bed load (sand and gravel)  a) rolling, b) sliding or traction, c) saltation

Question 5

Factors the affect stream flow

Answer 5

1) Gradient ->the amount the stream falls between two points (change in elevation/distance between two points)
2) Discharge ->the amount of water that passes down the river (m3/s)
->cross-sectional area x average velocity
3) Velocity
4) Sediment load

Question 6

Dendritic Drainage Patterns

Answer 6

Moderate slopes and rocks and soil of uniform resistance.

Question 7

Parallel Drainage Patterns

Answer 7

Parallel drainage patterns form where there is a pronounced slope to the surface. A parallel pattern also develops in regions of parallel, elongate landforms like outcropping resistant rock bands

Question 8

Trellis Drainage Patterns

Answer 8

Form in areas of hard and soft rock formations exist. Large streams occur in less resistant rocks and the smaller streams cur more resistant rocks in the higher ground
e.g., folded sedimentary sequences.

Question 9

Rectangular Drainage Patterns

Answer 9

Typical of little topography and bedrock with uniform resistance and orthogonal joint sets being planes of weakness and more easily eroded.

Question 10

Radial Drainage Patterns

Answer 10

Occurring on isolated topographic uplands such as volcanoes, domes and buttes
(steep-sided, flat-topped towers of rock)

Question 11

Two Types of Water Flow in Streams

Answer 11

1. Laminar Flow
   low velocities
   the fluid particles follow the streamlines
2. Turbulent Flow
   higher velocities
   the flow breaks up into a fluctuating velocity pattern or eddies (streamlines cross)

Question 12

Two types of floodplains

Answer 12

1. Braided Rivers: have numerous channels that repeatedly divide and merge
2. Meandering rivers: consist of a single main channel that bends and loops

Question 13

Flood Plains

Answer 13

 a flat region of a valley floor located on either side of a stream channel, common location for
meandering streams
 is built of sediments deposited by the stream that flows through it and is covered by water
during floods
 floodplains tend to develop on the less steep sections of streams.

Question 14

Types of Stream Deposit Types

Answer 14

1. FloodPlains
2. Levees
3. Terraces
4. Alluvial Fans
5. Delta