Introduction
The environmental science students took advantage of our school’s location next to the local creek and went on a trip to the Jangsan Creek in order to use it to expand our knowledge about environmental science. On this trip, we were able to get an effective hands-on learning experience through determining the stream flow of a creek. This experiment is related to environmental science because one important factor in determining the water quality is to evaluate the stream’s flow. For example, high temperatures, low levels of dissolved oxygen, and levels of toxins can all be affected by a low stream flow and vice versa.
The section of the creek that my group chose
The Experiment
In order to determine the stream flow, the environmental students needed the following equipment:
- Meter stick (to measure the depth)
- Tape Measure (to measure the length and width)
- Tennis ball (to measure the stream’s speed)
- Stopwatch (to measure the time)
Due to measuring the overall stream flow of an entire creek is a tedious and time-consuming work even for professionals, the environmental science students chose a section of the stream to work with in order to determine the section’s stream flow. After choosing their section, they measured the length, width, and depth of their stream’s section using the tools stated above. Then, they gathered the data in order to determine the stream’s velocity through measuring the how long it took for a tennis ball to flow down their section. The students repeated the process at least four times in order to have accuracy. Throughout the process, the students recorded their data in their field notebooks in order to calculate the stream flow.
The Calculations
The section of the stream that my group chose had the following measurements that we collected:
| Location | 1 |
| Depth (cm) | 32 |
| Distance (m) | 2 |
| Trial 1 (s) | 2.67 |
| Trial 2 (s) | 2.43 |
| Trial 3 (s) | 2.33 |
| Trial 4 (s) | 2.00 |
| Location | 2 |
| Depth (cm) | 16 |
| Distance (m) | 1.3 |
| Trial 1 (s) | 4.39 |
| Trial 2 (s) | 3.20 |
| Trial 3 (s) | 4.32 |
| Trial 4 (s) | 5.62 |
(We decided to separate our section in half because the left and the right side had different factors that cause a difference in the stream flow i.e. rocks and plants).
Using this data, our group estimated what the interior of the stream looks like an made a diagram:
Through this, we determined the area/cross section of the halves, labeled location 1 and location 2:
Location 1:
Area = l(w)
Area = (130)(32)
Area = 4160 cm2
Location 2:
Area = (bh)/2
Area = ((200)(16)) / 2
Area = 1,600 cm2
Then, we calculated the velocity through using the equation, Rate = Distance(m) / Time(s), and calculated the average of the four trials per location:
RateAverage(Location 1) = 0.855 m/s
RateAverage(Location 4) = 0.30 m/s
Lastly, we determined the stream discharge through the equation: Discharge = (Rate)(Area).
Discharge location 1 = 2.055x10-4cm3/s
Discharge location 2 = 1.810-4cm3/s
Overview
Overall, the experiment was educational due to it being very interactive. Personally, I enjoyed this trip and experiment due to it allowing the students to have a hands-on experience in the field and using teamwork in order to gather the information needed for the stream flow.
Students working together in order to gather information
Written by Cloe Lee (BFS Student)