Stream Table Experiment
Make no marks on this page. Put all answers on your own paper.
A.
Young River: Use one block under your stream table at the end of your sand. With a
spoon or sand tool, trace a straight stream from the top to the bottom of your sand.
Adjust your water so it is coming out very quickly.
Questions:
1. Describe the movement of the particles as they are washed into the lake. (Do
they float, tumble or what?)
2. Why do sand grains stop at the edge of the lake?
3. What do you call the structure being created by the sand grains at the mouth of
the river?
4. Describe this structure. Where is it changing?
5. Why are so many large pebbles found in the main river channel?
6. Where is the water picking up material in this type of river?
B.
Add another block under your stream table. Observe the results.
7. What do you notice about the rate of erosion with this change?
8. Has the delta changed at all? How?
9. Why might it have changed?
10. What effect does the slope (steepness) have on how fast the material is eroded?
Explain.
11. You have just built a young river. What characteristics do young rivers have?
C.
Stop the water. Remove one of the blocks from below your stream table. Smooth out
the riverbed and create a river with multiple meanders.
12. When you look at the water running around the meanders, can you see where bits of
fine sand are being picked up and carried downstream? Where is this happening?
(On the inside or outside of the curves?)
13. What happens to the sand grains when they are picked up?
14. Where were the sand grains deposited again?
Examine the inside of the meanders. There seems to be a collecting of sand into sandbars
on this side of the turn. This is called a point bar.
D.
Adjust the speed of the water to that which you used for a young river.
15. What do you notice about the rate of erosion?
16. Examine the outside of a meander and observe what is happening there. Explain why
the outside of a meander is called a cut-bank.
17. What is the reason for rivers dropping sediment on the inside of the curve and
eroding material form the outside of a curve?
18. You have created an early mature river. What characteristics do mature rivers have?
E.
Stop the water. Smooth out the riverbed and create a river with even more meanders
than the previous river. Make sure you have only one block under your steam table and
slow your water speed down.
19. What is created when the water bypasses a curve and breaks through the river-bank?
20. You have just created a late mature river. What characteristics do late mature rivers
have?
F.
Smooth out your land surface and create a new stream with a dam towards the bottom of
the river. Make sure your human made lake has plastic showing on the bottom. Allow
the water to flow over part of your dam.
21. Where does eroded sediment from up stream end up?
22. What will happen to the water depth of your reservoir over a long period of time?
23. What problems would this cause in the real world?