1. *Running water is the Earth’s main agent of natural erosion

2. Lesson 9: Energy in a streamB C
Youthful
Stream
Middle- Age
Stream
Old-Age
Stream

3. What shapes streams?
Weathering: chemical and physical breakdown of sediments.
Erosion: removal and transport of sediment by natural agents.
Deposition: release of sediments from an erosional system (AKA Sedimentation)

4. Low Kinetic & Potential Energy
Stream Side View
Greatest Potential Energy = Stored Energy
Greatest Kinetic Energy = Energy of Motion
Lake
Ocean
Most Erosion
Low Kinetic & Potential Energy
Most Deposition
Kinetic energy= energy in motion
Potential energy= energy that is stored

5. Changing Stream Velocity:
A. Slope increases, velocity increases
B. Volume (Discharge) of water increases, velocity increases
Velocity determines size of sediments
ESRT pg 6

6. River Landscapes in America
Yuba river, Nevada

7. How sediments move - Flow of the River River Floor Cobbles & Pebbles
Move by sliding, rolling
Slower than the water
Silt, Clay & Dissolved Ions
Moves in suspension
Same speed as water
Sand
Moves by Bouncing
Slower than water
River Floor

9. Different size particles
Well Sorted
Same particles size
Unsorted
Different size particles

10. Stream deposits are well sorted
(same size)
Example:
“Delta”
Forms when a river carrying sediment reaches a body of water. The river water spreads out, velocity slows and deposits sediments.

13. Clear water
suspension
suspension
Area of vegetation

14. Amazon Delta

15. Q1:

16. Q2:

17. Q3:

18. Q4:

19. Q5:

20. Q6:

21. Q7: State the maximum size particle (cm) that can
Use Particle Size versus Stream Velocity Graph on “Baby” page 6
Q7: State the maximum size particle (cm) that can
be transported in a 1cm/sec moving stream.
Q8: What is the maximum stream velocity needed to
transport a 2.0 cm size particle?

23. Life Cycle of a Stream

26. Youthful Characteristics
Middle Age Characteristics
Old Age Characteristics

27. Youthful Stream Lake (Source of Water) Waterfall Steep Slope
Rapid Flow
Rapids

28. V-shaped valleys

29. Middle Age Velocity decreases due to decrease in slope
Begins to meander
Downcutting slows due to velocity decrease
Valley walls become wider

30. Old Age Stream Slow speed Almost flat slope
Very broad, flat valley (flood plain) filled with fine sediments - alluvium
Very little erosion
Oxbow lake
Wide meanders
Wide flood plain

31. Oxbow lake – a meander becomes so great, it cuts off forming a lake.

33. Rejuvenation – a stream may be brought back to a youthful stage of development at any time by ……
(ex. Grand Canyon)

34. Uplift of land; create a steeper gradient.
Resulting in..
Higher stream flow and more downcutting of valley
2. Stream takes on more discharge by tributaries resulting
in more downcutting.

35. Name the part of the stream’s life cycle in the picture