Chapter 9 Sec. 2

1
Chapter 9 Sec. 2

• Stream Development

2
Moving Water

• Adequate supply of water
• What happens to streams in areas of high
  precipitation?
• What happens to streams in areas of low
  precipitation?
• The region where water first accumulates is known
  as what?
• Headwaters
• Where are common areas for head waters?

3
Stream development

• As water accumulates in high in small gullies,
  water starts to move downward
• Stream channel
• narrow pathway into sediment or rock that the
  moving water carves
• The moving water is held in by ___________, the
  ground bordering each side.

4
Stream development

• The process by which small streams erode away
  soil and rock ahead of the stream is called
  ______________
• What does head ward erosion do to the stream?
• Lengthens
• What is stream capture?

5
Stream Valleys

• As streams erodes creates a V-shaped valley
• Grand Canyon
• Continues until it reaches a base level
  elevation where it enters another stream
• Lowest base Sea Level

6
Meandering Stream

• Streams slope decreases as it reaches base level,
  as result, the channel gets wider. Why?
• Creates build up in the stream and erodes the
  sides of the channel
• Starts to bend or wind called a Meander
• Velocities of the water differ from where it is
  located within the stream.
• Outside greatest velocity
• Inside slowest velocity
• Diagram

7
Deposition of sediment

• Streams lose velocity lose the ability to carry
  sediment
• Alluvial Fan
• Sloping depositional features from bases of
  slopes
• Sand or gravel
• Death Valley
• Delta
• Triangular deposit into larger, quieter bodies of
  water
• Silt and clay
• Mississippi River

8
Age of streams

• Youth, Mature, Old
• Rejuvenation to make young again
• Stream actively resumes down cutting towards its
  base level
• Causes the channel to become V-shaped and start
  over