Stream Table Lab.
First Entry
Purpose: To study the effects of stream flow on erosion.
Prediction: Slope, amount of water, type of sediment will effect erosion.
Second Entry
Question: Will the amount of water affect the amount of erosion?
Hypothesis: If the amount of water increases then the amount of erosion increases, because there are more force and mass moving down the slope causing erosion.
Third Entry
Planning
Set up
- Place the stream table so that the end without the drain is resting on two wood blocks.
- The drain tube should empty into a bucket in the sink or on the floor.
- Set the water source at the opposite end of gutter.
- Smooth the sand so that it is evenly spread, leaving a space of about one foot at the low end of the gutter with no sand.
- Measure and record the distance from the high end of the stream table to the edge of the sand.
Practice:
- Fill the bucket that you are using as a water source. Keep the tubes above the lip of bucket so that no water escapes until you are ready.
- Place one tube centered near the top end of the stream table to allow water to begin flowing down the sand.
- Start timing and allow this to continue for five minutes.
- Continue filling the water source so water flow is not interrupted. Note observations wile the streambed forms.
- STOP after five minutes.
- Record observations:
How does the stream initially form a path?
Does the path change as the stream continues to flow?
Has a delta formed? Record its shape.
Sketch the stream bed after five minutes.
- Allow the stream to flow for five more minutes, recording the same observations.
- Scoop the sand that is eroded into a cup. Weigh them. The cups weigh 7.9 gram each. Don’t forget to subtract these.
- Reshape the sand. Follow same procedures above using more tubes to allow more water to flow through your stream table.
- CLEAN UP
Data table.
|
Amount of water (Tubes) |
Amount of sediment eroded. (Mass. g) |
|
1 Tube |
572.1 |
|
2 Tube |
1014.6 |
|
3 Tube |
1171.3 |
Fourth Entry
Description:
1 tube.
A meander was formed at the side of the stream table (since the stream table was sort of leaning towards the outer side.) The stream channel was small, water wasn’t running very quickly. A stream piracy formed, but eventually dried up. Delta was also formed at the end of the table. It wasn’t very large. The edges were gentle, uneven cut.
2 Tubes
As a result of not holding the two tubes together, a stream piracy was formed. But dried up after we held the tubes together. The stream channel was deeper and wider. Part of stream table which the running water first hit was exposed. Larger sediment was eroded. Delta formed, quite big and spread out. The edges were steep, sediment kept falling off the steep side, forming a landslide.
3 Tubes
Much of Stream table exposed by rushing water. Very deep and wide stream channel. Meander and V shaped valley formed. A lot of sand eroded. Delta formed, very very large, edges very very steep.
Fifth Entry
We have done a lab based on the characteristics of water erosion. Our question was will the amount of water effect the amount of erosion. The independent variable is the amount of water, and the dependent variable is the amount of erosion. Gravity and slope stays the same. According to the data, the amount of erosion increases as we increase the amount of water moving down the slope. As water increases, mass increases, so then there will be more force to move sediments, and then amount of erosion increases. We also noticed that the amount of water can also affect the speed of erosion, width of the stream channel and area of delta.