1. Topic: Erosion & Running Water
* Earth’s main agent of natural erosion

2. What is erosion?
Erosion is -

3. Agents of Erosion Agents of erosion include --
Running water is the big Kahuna of all erosional agents.

4. How does water carry the sediments?
Water carries sediments in the following ways:
Solution – -
Suspension – -
Rolling or bouncing along the streambed.
Floating – -

5. Streams act as conveyor belts
River Floor
Flow of the River
Cobbles & Pebbles
Move by sliding, rolling along the river floor
Slower than the water flow
Colloids (Silt & Clay) & Dissolved Ions
Carried in suspension
Same speed as water
Sand
Bounces along river floor
Slower than the water flow

6. Low Kinetic & Potential Energy
Stream Side View
Greatest Potential Energy = Stored Energy
Greatest Kinetic Energy = Energy of Motion
Lake
Most Erosion
Low Kinetic & Potential Energy
Most Deposition
Ocean
Dynamic Equilibrium
Rate of Erosion = -

7. Changing Stream Velocity:
B. --
Stream velocity determines size of sediment carried.
ESRT pg 6  Take out your ESRT!

9. Streambed --

10. Stream bank --

11. Region of maximum stream velocity changes when streams bend or turn.
Region of maximum velocity shifts to --
Region of minimum velocity shifts to --

12. Since the region of maximum stream velocity is at the outside of the curves, streambeds are more eroded at the outside of curves. A A’
Streambed B’ B
Streambed C C’
Stream
bed
Stream A A’ C’ C B B’

13. What does erosion by rivers create?
Abraded sediments --

14. FQ
The stream’s velocity is 100 cm/sec, what size sediment(s) can the stream transport?

15. ---

16. Topic: Life Cycle of a Stream

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

18. This forms V-shaped valleys.

19. ** ---**

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

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

22. Meander – --

23. Oxbow lake – --

25. Rejuvenation – a stream may be brought back to a youthful stage of development at any time by uplifting the land.
(ex. Grand Canyon)

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

32. What shape do stream valleys make?
FQ:
What shape do stream valleys make?
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