Isaiah Brisbane
B4
Haines
03/24/15

Investigating Surface process - stream table erosion lab Introduction:We want to see if the slope of a river will change the amount of erosion.
Problem: how much does the slope of the land affect the amount erosion created by a river?
Research:
The major Parts of a river include, the river source / headwaters, the tributaries, the river channel, the river bank, and the mouth / delta. Erosion is the process of wearing away rocks, geologic, and soil material via water, wind, or ice (e.g., glaciers). Five erosion control methods: planting vegitation, erecting barriers like rock piles, putting mulch down, plant structural trees, and build retaining walls. “Erosion is the process of wearing away rocks, geologic, and soil material via water, wind, or ice (e.g., glaciers). Erosion will transport materials after mechanical weathering has broken rock and geologic materials down into smaller, moveable pieces.” http://www.waterencyclopedia.com/En-Ge/Erosion-and-Sedimentation.html#ixzz3YHoZ2FdV Hypothesis: If river erosion starts to break down all the bedload, then the water in the river channel should increase the size of the channel by taking away some of the bedload. because, based on my research, the water will start to carry the sand and gravel away. (be specific as to whether the land is steep or flatter in elevation)
Procedure and materials: water table, sand, ruler, water pump, wood planks Create land for the river bed Create a river with 2 bends. the river will be 4 cm wide and 2 cm deep. run the water for 1.5 now run the water for 3 mins measure the stream bed each time. change the slope. then repeat.
Experiment
Independent variable: The slope Dependent variable: depth and width of the river channel at the head, center, and mouth of the river. Control: River channel measurements on flat ground.
Collect Data
Qualitative Observations: (What you saw happen in the following pictures as far as the width and depth of the river channel and the delta, AND where the sand gets deposited and eroded..
We began with 4 cm wide and 2 cm deep of a river channel.

Medium slope: At the mouth of the river the channel got deeper.

Medium slope: Meander and mouth changing. the erosion gets worse and the channel gets deeper by the mouth of the river. The channel got much wider and more shallower than before.

Steep slope:The channel got a lot more deeper and wider as it eroded to the left side of the stream table. The channel became a braided river because it cut straight across the channel we had originally made.

steep slope: The channel erosion ended up exposing the rocks at the bottom and started moving the rocks.

steep slope delta: The sediment got carried to the delta which made the sediment pile much thicker.
Quantitative Observations: (Charts of data)
Quantitative Observations-
Locations
Minutes
Width
Depth
Head
Medium >
Steep >

NM - 4 cm 7 cm 9 cm
NS - 4 cm 7 cm 8.5 cm

NM - 2 cm .25 cm 1 cm
NS - 2 cm 2.5 cm 4 cm
Center Channel
Medium >
Steep >

NM - 4 cm 5 cm 16 cm
NS - 4 cm 5 cm 9 cm

NM - 2 cm 1.5 cm 1cm
NS - 2 cm 3 cm 4 cm
Mouth
Medium >
Steep >

NM - 4 cm 8 cm 30 cm
NS - 4 cm 9 cm 17 cm

NM - 2 cm 4 cm 5 cm
NS - 2 cm 5 cm 4 cm

ANALYSIS- Remember, this is an explanation of your data and results in the previous sections.
Explain any significant differences you find interesting in your table.
The medium slope’s mouth went from 4 cm wide to a whopping 30 cm wide.

Did you observe large changes in numbers for the width of the stream’s head, center, mouth or depth? Yes, the biggest jump in width was at the mouth of the medium slope it went from 4 cm-30 cm.

Describe the sediments, patterns of waterflow, interesting collections or patterns of rocks and sand.
The sediment was dug up a lot on the left side right in the middle of the steep slope’s channel, which exposed the rocks that were deep down under all the sediment.

Conclusion: The conclusion is where you should reflect on your hypothesis and conclude whether or not you have proven your hypothesis.
Did you prove your hypothesis? Why or why not?
Yes my hypothesis was just about right, because the water ended up eroding the bedload which caused the rocks to be exposed.

Describe what properties of water make it challenging to stop erosion and which material we found most effective at slowing down the rate of erosion.
The water can weave it’s way through all the sediment and break it down through time.