1. Section 13.1 Streams and Rivers

4. Important Definitions!
____________ – a stream and all its tributaries
________ – a smaller stream that empties into a larger stream
______ – a high point that separates river systems
_________ – the land area drained by a river system
River System
Tributary
Divide
Watershed

5. Characteristics of Streams and Rivers
3 factors that determine a streams velocity:
gradient
discharge
channel shape

6. Gradient how steep or flat a river is
steeper the gradient, the faster the river will flow

7. Discharge
the amount of water that passes by a certain point in a given amount of time
varies depending on the time of year and the weather conditions

8. Channel Shape path that makes up a river
velocity of a river depends on the depth of the channel and how winding it is

9. Stream Erosion and Deposition
Section 13.2
Stream Erosion and Deposition

10. Stream Erosion and Deposition
Velocity and discharge affect how much material a river can transport. When river velocity greatly decreases, sediment drops out of the water to form a delta or alluvial fan.
Over time, sediments build up, forming a delta.

11. Stream Weathering and Erosion
Deposition
process by which the material is deposited

12. Erosion
Pothole
Deep circular basin developed when the river develops small whirlpools

13. Pothole

14. Transporting Material
Load
Downstream
Eroded rock and soil
By action of the river
Suspension
Muddy looking
Clay, silt, and fine sand
Between the water molecules
Bed Load
Rock transport

15. Stream Load/Suspension

16. Stream Competency vs. Capacity
Total amount of sediment the stream can carry
Competency
Maximum size of particle the stream can carry

17. Stream Deposition Increase velocity more movement
Decrease velocity more deposition
Everything held by the water will be deposited

18. Delta
Fine sediment
River slows down to a body of water

20. 13.3
River Valleys

21. Headward Expansion
Land is worn away at the head of a river/stream

22. Canyon and V-Shaped Valleys

23. Progression

25. Base Level Level to which the stream can go down
Set by the body of water the stream enters

27. Waterfalls
Differential erosion
Hard top
Soft under-strata

28. Section 13.4 Floodplains and Floods

29. What is a flood? What is a floodplan?
river or stream overflows its banks
What is a floodplan?
area along a river that is most susceptible to flooding

31. Flood Prevention Restoring natural plant life in areas along rivers
Dams can help to control the amount of water moving downstream
Artificial levees such as sandbags can be put into place as a temporary solution
Maintain safe floodplains by not allowing people to develop the land in a floodplain