Observation summary - Group 1

Initial Test: (Jan 12)
Parameters:  Sediment supply: None
                   Stream Velocity: 35
                   Gradient: 2 deg.
                   Initial channel shape: None
                   Base Level: 3.6 cm

Hypothesis: The water will create initial channels then create sub channels similar to a braided stream. Because we are starting with no particular calculated measurements this will probably happen instead of sustaining a true meander.  
Observations: We began the experiment and the water flooded toward the North. (Jan 14) No significant change.  Water flooded on the North side, slight headward erosion at basin. Base level rose.



Test 2: (Jan 14) 
Change: We are going to increase the velocity by 50% to 52.5 to help move the sediment.
Hypothesis: The increase in water velocity will increase the depth of erosion and move more sediment to allow lateral migration.
Observations:  Initially when changing the velocity it was noted that sediments were transported more rapidly. (Jan 19) A straight, shallow channel formed, most defined closest to the water input. Splays developed downstream. Riffle pools of swirling water and sediment were created in turbulent areas. (Jan 21) No change since last observations. The stream table must have reached equilibrium.

Test 3: (Jan 21)
Change: We are going to add sediment input.
Hypothesis: The increase of sediment input will help our stream become more as a real meander by shaping the stream better.
Observations:  We developed a system to input sediment into our stream table. (Jan 24) Our channel has now been filled from the additional sediment. The water flows on top of the sediment now.  Large fan deposits of coarse material and some fine grained flood deposits can be noted.

Test 4: (Jan 24)
Change: Lower base level
Hypothesis: This will cause heavier erosion because the stream can now erode deeper.  We hope this will also help to develop channel migration and continue in developing stream features.
Observations: As we lowered base level, there was immediately heavy erosion at the head of the river with headward erosion (down cutting). This erosion went on steadily for 30 minutes (about 1 1/2 ft) until it began to slow.