Maggie,+Ellen,+Kayla

Maggie, Ellen, Kayla

**Introduction **
Streams are the most important agent of erosion (5). They transport huge amounts of sediment in dissolved, suspended, and bed loads. Dissolved loads carry the smallest sized sediment, such as clay. Suspended loads carry small sediment that hang in the water, and when they travel, suspended loads look like clouds in the water. Suspended loads give some rivers a murky look, or a different color, such as the Yellow River in China. Bed loads are the largest sediment transported by streams. These sediments are transported by scooting and rolling across the bottom of the stream(5). Eventually, each load is deposited into the stream bed (3,5). Sediment will then create depositional features such as deltas, flood plains, and oxbow lakes(5). The transportation of sediment relies on the stream's velocity, or current speed, as well as the geologic features of the area and the climate (5,3). The stream could not carry sediment without the immense amount of energy in the stream's current (5). For example, geologic features, such as trees and vegetation, can fall into the stream and create a natural dam, thus slowing down the velocity on the opposite side of the tree because energy cannot pass through. Streams with a high current speed will transport larger pieces of sediment to farther locations (5). “Competence” is a term that refers to the largest pieces of sediment a stream can transport (5). Competence is affected by velocity, and as velocity doubles, competence quadruples because the stream has enough energy to lift heavier pieces of sediment (5). Therefore, the higher the velocity of a stream, the higher the competence, and the larger the sediment size that will be transported in the stream bed (5). The largest sediment is located in the center of the stream bed because that is where friction is the lowest, therefore there is less resistance, letting the water flow faster (5). On the banks of the stream bed there is more friction so the velocity is lower and the smaller sediment is deposited (5). There is more friction on the outer bank of a meander so the velocity is lower and smaller sediment sizes are also deposited here (3,5). There is less friction near the point bank of the meander so medium size sediment is deposited there. (5). Velocity is also highest in more narrow stream beds because there is more water flowing through a smaller area at once, with less surface area to cause friction (5). Critical settling velocity is a velocity in which certain sized sediment will be dropped. Larger pieces of sediment will have a higher critical settling velocity than smaller sediment, so only larger sediment is deposited in the center of the stream bed, making the sorting of the sediment consistent (5). The smaller particles of sediment sometimes dissolve in the water, in which case this does not affect the sorting because the sediment is not deposited into the center of the stream with a high velocity (5). Each size of sediment has a specific critical settling velocity so only sediment at that particular speed of velocity that has that settling point will be deposited into that part of the river (5). Furthermore, sediment sorting is affected during the transportation of sediment. Sorting is the degree of uniformity of grain size (1). A well sorted sample will contain sediment of similar size and a poor sorted sediment will contain sediment of varying sizes (1). As velocity increases, the sorting of sediment stays consistent, and the sediment size increases.

**Materials **
1. Flow meter 2. Sieve 3. 72 small containers 4. Timer 5. Small kitchen scale 6. String 7. Centimeter ruler 8. Scissors 9. Small dish

1) Determine river that will be tested (Fuller Brook Path, Upson Road Brook, Twitchell Road Brook).
 * Methods**

2) Find 3 locations on each stream--each location with varying velocities. Locations with high velocities will be found after a bend in the stream or in areas when stream channel becomes narrow. Medium velocity locations may look moderately wide and be on a straightaway. Low velocity locations will be found when the stream channel becomes wide. None of the locations should have obstructions near the tested area, or man made structures within 6 feet of location that block the flow of water. In addition, these locations should be at least 6 feet in distance from each other.

3) Then, within each location, find 3 spots to take sediment samples from (left side, middle, and right side of streambed).

4) Collect a sample of sediment from each location and label the container or bag with the location, sample #, velocity of current location, and the stream where it was taken. When collecting the sediment, make sure to only collect the top layers of sediment, digging no more than one inch down to keep the data accurate. Collect a small amount of water with your sample, as the water will evaporate and leave behind fine sediment.

5) Measure the velocity in each testing location using the flow-meter. First, stick the flow meter into the water straight and go into the middle depths of the current. Make sure the propeller is spinning and to never stand in front of the flow meter. Start your stopwatch and the flow-meter at the same time. To turn on the flow-meter, you press the button and wait for an increasing number on the screen.

6) Repeat above step for each of the 3 locations, at left, middle, and right for each location.

7) After all data samples are collected, leave each sample separately in a pan near sunny window to dry, or it is also possible to put the collected sediment on pie pan sheets to bake and dry.

8) Pour one sample into the sieve and shake.

9) For each layer of the sieve, pour sediment onto scale using a previously massed dish, and take the mass of the sediment in grams on either a digital or analog kitchen scale. Record in grams and subtract the weight of the dish.

10) Repeat steps 8 & 9 for each of the samples.

11) Sediment will be in mass per sieve. Convert to percentages. Take each sieve section mass, divide each section by the total mass of the complete sample, then multiply by 100

12) Find the largest particle of sediment in each sample and set aside.

13) Find the mass of this largest piece of sediment using a kitchen scale. Record in grams.

14) Measure circumference of largest piece of sediment using string. Cut the string to the exact size of the circumference.

15) Measure length of string with a ruler. Record in centimeters.

__**Twitchell Brook Data Collection:**__

 * The Effect of Velocity on Sediment Size**


 * **Velocity (MPH)** || **Largest Rock Size (Grams)** ||
 * 1.1648 || 121 ||
 * 0.8064 || 25 ||
 * 0.448 || 1 ||
 * 0.9856 || 30 ||
 * 0.5824 || 32 ||
 * 0.6944 || 7 ||
 * 0.7616 || 24 ||
 * 0.4928 || 20 ||
 * 0.4256 || 29 ||
 * 0.9408 || 58 ||
 * 0.47264 || 8 ||
 * 0.4704 || 40 ||
 * 0.6944 || 60 ||
 * 0.1792 || 0.01 ||
 * 0.9632 || 40 ||
 * 0.224 || 7 ||
 * 0.4928 || 10 ||
 * 0.56 || 17 ||
 * 0.8064 || 9 ||
 * 0.448 || 11 ||
 * 0.5376 || 20 ||
 * 0.8069 || 32 ||
 * 0.148 || 28 ||
 * 0.6272 || 17 ||
 * 0.2688 || 0.2 ||
 * 0.3808 || 0.3 ||
 * 0.4032 || 1 ||
 * 0.224 || 0.8 ||
 * 0.1568 || 0.08 ||
 * 0.672 || 2 ||
 * 0.448 || 10 ||
 * 0.3808 || 0.2 ||
 * 1 || 0.1792 ||
 * 0.3080 || 0.02 ||
 * 0.896 || 4 ||
 * 0.3338 || 3 ||
 * 0.336 || 0.2 ||
 * 0.8064 || 0.5 ||
 * 0.7614 || 98 ||
 * 0.6496 || 1.6 ||
 * 0.4032 || 0.009 ||
 * 0.2016 || 0.4 ||
 * 0.3807 || 6 ||
 * 0.3338 || 13 ||
 * 0.403 || 0.98 ||
 * 0.4928 || 0.67 ||
 * 0.9856 || 5 ||
 * 0.3808 || 3 ||
 * 0.8064 || 60 ||
 * 0.9632 || 32 ||
 * 0.4982 || 28 ||
 * 0.3136 || 24 ||
 * 0.36736 || 7 ||
 * 1.12 || 24 ||
 * 0.448 || 3 ||
 * 0.336 || 2 ||
 * 1.1648 || 20 ||
 * 0.5152 || 15 ||
 * 1.702 || 77 ||
 * 0.392 || 3 ||
 * 0.7616 || 11 ||
 * 0.3584 || 22 ||
 * 0.9184 || 30 ||
 * 0.1568 || 1 ||
 * 0.3696 || 0.4 ||
 * 0.84 || 1.3 ||
 * 0.8512 || 5 ||
 * 0.34944 || 5 ||
 * 0.4144 || 12 ||
 * 1.4694 || 33 ||
 * 0.9408 || 6 ||
 * 1.8368 || 102 ||
 * Effect of Velocity on Sediment Sorting**


 * Velocity (MPH) |||| % of Majority Sediment Size ||
 * 0.148 || 57.82 ||  ||
 * 0.5376 || 68.46 ||  ||
 * 0.448 || 47.36 ||  ||
 * 0.56 || 70.39 ||  ||
 * 0.5824 || 47.51 ||  ||
 * 0.448 || 26.71 ||  ||
 * 0.224 || 40.19 ||  ||
 * 0.6272 || 43.76 ||  ||
 * 0.8069 || 70.76 ||  ||
 * 0.7616 || 63.6 ||  ||
 * 0.9408 || 76.62 ||  ||
 * 0.6944 || 62.8 ||  ||
 * 0.9408 || 93.08 ||  ||
 * 0.4928 || 62.3 ||  ||
 * 0.9632 || 62.8 ||  ||
 * 0.9856 || 62.3 ||  ||
 * 0.8064 || 46.68 ||  ||
 * 0.4726 || 54.65 ||  ||
 * 0.4928 || 55.52 ||  ||
 * 0.1792 || 55.19 ||  ||
 * 1.1648 || 68.33 ||  ||
 * 0.8064 || 64.51 ||  ||
 * 0.4256 || 61.34 ||  ||
 * 0.4704 || 55.83 ||  ||
 * 0.392 || 49.57 ||  ||
 * 0.9184 || 83.1 ||  ||
 * 0.3584 || 58.12 ||  ||
 * 0.9408 || 41.34 ||  ||
 * 0.7616 || 65.91 ||  ||
 * 0.4982 || 51.42 ||  ||
 * 0.3494 || 57.47 ||  ||
 * 0.4144 || 63.8 ||  ||
 * 0.3674 || 46.57 ||  ||
 * 1.4694 || 94.9 ||  ||
 * 1.7024 || 90.23 ||  ||
 * 0.3136 || 60 ||  ||
 * 0.84 || 47.86 ||  ||
 * 0.3696 || 53.76 ||  ||
 * 1.8368 || 94.83 ||  ||
 * 0.1568 || 39.3 ||  ||
 * 0.8064 || 67.24 ||  ||
 * 0.448 || 53 ||  ||
 * 0.336 || 34.91 ||  ||
 * 1.1648 || 69.41 ||  ||
 * 0.5152 || 53 ||  ||
 * 1.12 || 60.6 ||  ||
 * 0.8512 || 64.15 ||  ||
 * 0.9632 || 67.7 ||  ||
 * 0.2016 || 56.42 ||  ||
 * 0.6496 || 50.69 ||  ||
 * 0.8064 || 39.9 ||  ||
 * 0.896 || 65.99 ||  ||
 * 0.9856 || 68.85 ||  ||
 * 0.0448 || 43.95 ||  ||
 * 0.3808 || 68.03 ||  ||
 * 0.224 || 82.23 ||  ||
 * 0.1568 || 45.77 ||  ||
 * 0.308 || 72.47 ||  ||
 * 0.3808 || 93.27 ||  ||
 * 0.336 || 65.99 ||  ||
 * 0.3808 || 70.92 ||  ||
 * 0.4928 || 86.26 ||  ||
 * 0.6048 || 84.36 ||  ||
 * 0.2688 || 81.39 ||  ||
 * 0.4032 || 73.63 ||  ||
 * 0.1568 || 70.19 ||  ||
 * 0.3338 || 56.72 ||  ||
 * 0.1792 || 62.41 ||  ||
 * 0.7614 || 53.61 ||  ||
 * 0.672 || 38.46 ||  ||
 * 0.3807 || 73.63 ||  ||
 * 0.4032 || 37.23 ||  ||

Graph 1:



Graph 2:



(MPH)

**Results** As shown in the graph 1, the higher the velocity, the larger the sediment. It can be concluded that the largest rock in each sample is the biggest piece of sediment possible for the stream to carry at that velocity within the critical settling point. In Graph 2, “The Effect of Velocity on the Sorting of Sediment,” it was also seen that the lower velocities had a greater portion of smaller sediment. In some locations it could be seen that with the higher velocities ranging from .84 MPH to 1.8368 MPH, that the ratio of large sediment to small sediment was over 50%. As the velocity decreased the ratio of large to small sediment dropped, with a larger mass of sediment from small size sediment. In the Twitchell Brook, it was found that with the lower velocities between .2688 MPH and .6496 MPH, the sediment deposited was smaller and had a ratio above 50% over the rest of the sediment within the sample. The Brook Path samples continued to support the patterns shown in both the Twitchell Road Brook and the Upson Brook, since with an increase of velocity in some locations, the sorting of sediment remained consistent to the size, and the sediment size increased. When the velocity drops, the sediment below the critical settling velocity is deposited and the overall sediment size decreases. Graph 2 cannot fully support the hypothesis given that there is no clear trend in the data

**Discussion** The major findings from this experiment consistently support a portion of the hypothesis correct: as velocity increases, the sediment size increases. However, the data did not fully support the hypothesis that sorting remained consistent as velocity increased. Graph 1, “The Effect of Velocity on Sediment Size”, supports the fact that when velocity increases, so does sediment size and weight. The results can be generally characterized because most of the data proves the hypothesis correct, except for a few outliers. For example, in some areas of lower velocities, such as between 0.6 and 0.8 MPH some sediment ranged from around 60 to nearly 100 grams. The average in this particular area however, was about 15 grams through 30 grams. It can be concluded from the data that the higher the velocity, the larger the sediment is that is deposited in that area. On the outer banks of the streambed, there is more friction because of stream channel contacting the sides of the bank. When friction is created there is more resistance to flow and there is a lower velocity due to the friction. This means that smaller sediment sizes will be carried and deposited onto the outer banks because the velocity is not high enough to carry larger pieces of sediment5. Since in the middle of the stream bed there is less friction, there is also less resistance for the water to flow5. This lets the water flow faster and will then have enough energy to carry larger pieces of sediment. The critical settling velocity of different sized particles is another reason this data has occurred this way5. When sediment is picked up in a dissolved, suspended, or bed load, the sediment will only fall to the bed of the stream, where the velocity is at the right speed to drop a certain size of sediment2. Only at a certain velocity will the sediment drop out in regard to the critical settling velocity of the sediment5. The smaller pieces of sediment during transportation are not dropped in as large quantities where the velocity is high enough for larger sediment to be dropped. The smaller sediment is moving too fast to be deposited, so the sediment will continue to be carried, until the velocity drops to a lower speed, appropriate for the size of the sediment to drop5. On the contrary, where the velocity is low, the larger pieces of sediment will not be picked up and the small sediment will drop at their critical settling velocity5. These findings are extremely significant for others. Knowing that streams of higher velocities contain larger pieces of sediment can help geologists uncover earth’s rock record and understand why rocks are in a certain location. Geologists can assume a stream of high velocity contains larger pieces of sediment and that a stream of low velocity contains rocks of smaller sizes. Therefore, a landscape consisting of large pieces of sediment could suggest a stream of high velocity once existed. Knowing how sediment is transported and the largest amount a stream can transport is critical in understanding streams as an agent of erosion and deposition. If the stream’s velocity is increased, it can be predicted that sediment size will increase in the stream channel. Construction workers would find this knowledge useful. If you are building a bridge across a stream and there is a pillar midway through the bridge, workers need to know what material the pillar is digging in to. They can collect samples of sediment or, using the results in this experiment, they can simply study the stream’s velocity. This will give them an estimate of how large the sediment in the stream will be. The size of the sediment will influence the stability during an earthquake if the structure is within a common earthquake zone, or the type of means of support needed for the bridge on land. In addition, our findings are useful for people who collect sand to sell for commercial purposes. Instead of sampling multiple streams for a specific size of sediment, they can just measure the velocity of a stream. This information can also be useful to contractors and homebuilders. Streams and sediment are major agents of erosion. When constructing a building along the side of a riverbank, it is important to know the rate of erosion along the shoreline. In areas of high velocity, the erosion will be increased because of the abrasion along the shoreline from large sediment in the stream, along with the erosion from the water. In areas of low velocities, the erosion will be much slower, since less destruction of the shoreline has caused small sediment within the stream. Knowing this is useful to contractors and homebuilders so that buildings can be constructed at a safe distance from the river’s edge to avoid the collapse of the building and the foundation. To perfect the experiment and to investigate the unsupported portion of the hypothesis, one could control all variables within a stream. It was attempted to control all variables in the streams tested, however, the experiment could not control the possibility of people throwing litter in the stream or different sized rocks. Also, it was difficult to control the great amount of organic matter at the bottom of a stream channel--which had to be picked out when massing the samples but everything could not be picked out. Organic obstacles such as fallen down trees also can affect the results. Samples taken after such obstacles may not be accurate, as it is unknown how long the obstacle has blocked the stream channel and changed the velocity. Clearing out an area of organic matter and sectioning the stream out from the public would improve the finding’s accuracy as well as the experiment. In addition to these, it would help to have a specific depth at which to dig for sediment to keep the data within the same time period as the current velocity. This is because a stream’s velocity can change depending on weather, organic or man made obstructions and changing geographic features. Holding these variables constant helps ensure that sediment collected was deposited at the current velocity. In conclusion, although most data supported the hypothesis, to investigate the unsupported portion of the hypothesis, more data can be taken along with improved methods in order to clarify the relationship between sorting and velocity.

1. Howard, Perlman, "Earth's water: Rivers and sediment," USGS,

April 11, 2011, last modified February 8, 2011,

< [] earthriverssed.html.>

2.

[|Irle, Patricia S. "Stream Hydrology - River, Depth, Temperature, System, Plants, Source, Effect, Human." //Water: Science and Issues//. 11 Apr. 2011. Web. May-June 2011. .]

3.

Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Gale Cengage, //Sedimentation:// World of Earth Science. 1 Jun, 2011 2003. eNotes.com. 2006.

< http://www.enotes.com/earth-science/ sedimentation>

4.

"Rivers and Sediment, from USGS Water Science for Schools Water Information Site." //USGS Georgia Water Science Center - Home Page//. USGS, 8 Feb. 2011. Web. 01 June 2011.

.

5.

Tarbuck, Edward J., and Frederick K. Lutgens, eds. //Earth Science//. Upper Saddle River, New Jersey: Pearson Education, Inc., 2009. Print

**information to support the hypothesis presented in the introduction. **
===**-Should begin by describing the major findings/patterns in data relative to the purpose of this experiment (is your hypothesis supported by the **=== ===**data or not?) making sure to reference the graphs in the results section in which this pattern is displayed. Use calculations! **=== ===**-Attempts to explain the significant findings using background information and answer the question; why did this **===

**happen?. **
===**-Be careful in the degree of certainty you give your explanations and findings (ex. suggests rather than proves). **=== ===**<span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">Be aware of systematic or specific errors that affected the overall results of your experiment and explain how/why **===

** The final draft shall be free of all such errors. **
SOURCES SECTION NEEDS WORK ====**<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">1- ** Howard Perlman, "Earth's water: Rivers and sediment," USGS, accessed ==== ====<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">April 11, 2011, last modified February 8, 2011, <span style="background-color: transparent; color: #000099; font-family: Calibri; font-size: 12pt; vertical-align: baseline;">[|__http://ga.water.usgs.gov/edu/__] ====

====**<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">2- **<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">Irle, Patricia S. "Stream Hydrology - River, Depth, Temperature, System, Plants, Source, Effect, Human." Water: Science and Issues. Web. 11 Apr. 2011. < <span style="background-color: transparent; color: #000099; font-family: Calibri; font-size: 12pt; vertical-align: baseline;">[|__http://www.waterencyclopedia.com/St-Ts/Stream-Hydrology.html__] <span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">>. ==== ====<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">**3-** "The Water Cycle: Streamflow." USGS. Accessed April 5, ==== ====<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">2011. Last modified February 8, 2011. http://ga.water.usgs.gov/edu/earthriverssed.html ====

**<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">4- ** Earth Science: 6.1 Running Water
====<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">Tarbuck, Edward J, and Frederick K Lutgens. "6.1 Running Water." In Earth ====

====**<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">5- ** Edward J Tarbuck and Frederick K Lutgens, "6.2 The Work of Streams," in ==== ====<span style="background-color: transparent; color: #000000; font-family: Calibri; font-size: 12pt; text-decoration: none; vertical-align: baseline;">Earth Science (Boston: Pearson Prentice Hall, 2009) ====