1. by Maddie, Ty, McKinley, and Garrett
Stream Erosion
by Maddie, Ty, McKinley, and Garrett

2. Parts of a River System

3. Tributaries: all of the feeder streams that flow into the mainstream
Watershed: the land from which water runs off into streams
Divides: ridges/elevated regions that separate watersheds
Channel: narrow depression that a stream follows as it flows downhill

4. Channel Erosion

5. Headward Erosion: in this process channels lengthen and branch out where the runoff enters the stream
Stream Piracy: a stream from one watershed is captured by a stream from another watershed that has a higher rate of erosion
the captured system drains back into the river that it stole from

6. Stream Load: the materials carried by a stream
suspended load
(fine sand and silt)
bed load
(coarse sand, gravel, and pebbles)
dissolved load
(mineral matter transported in liquid solutions)

7. Stream Discharge:
the volume of water moved by a stream in a given time period
The faster the stream flows, the higher the discharge and greater load it can carry.
Swift streams erode dirt channels more quickly than slow-moving streams do.

8. Stream Gradient :
change in elevation of a stream over a given horizontal distance
steepness
generally steepest at headwaters, flatter at mouth

9. Development of River CHannels

10. Meandering Channels
A developing river may for curves and bends
Meanders: winding pattern of wide curves
more bends with low gradients
causes erosions of banks, forms a bar of deposited sediment on the curve
Oxbow Lake: forms when meanders curve so much they form a loop and become isolated from the river

11. Oxbow Lake

12. Braided Streams Braided stream:
stream or river made of multiple channels that divide, rejoin around sediment bars
result of high gradient, large sediment load
cause as much erosion as meandering channel

13. List at least three parts of a river system.
Questions
List at least three parts of a river system.
What are the three types of stream load?
How does stream discharge and gradient affect the erosive ability of a river?