Above is a map of the section of the Ocmulgee River that we visited during our lab session. During this session we did three things: (1) flow rate testing, (2) clam collection, and (3) elevation measurement. For the flow rate testing, we used a tennis ball. One person stood in the water and another student stood 10 yards away, parallel to water flow. The student further upstream dropped the tennis ball into the water and we timed how long it took the ball to reach the student downstream. This information is then used to calculate the flow rate of the water.
Another group took samples of clams. They placed a large meshed sifter under water and when it was brought back up, the students totaled the number clams that were in the sifter, taking note of how many were dead and alive.
For elevation measurement, there were two poles connected by a 10 yard string. The poles were marked incrementally for height measurement. The poles were placed so that the string connecting them would be taunt. If the string was not completely horizontal when the poles were placed onto the terrain, the string could be adjusted up or down to make it so. This adjustment of the height of the string is what determined the depth in relation to the original spot on the river bank. This movement of the poles was continued for the width of the river transect.
No comments:
Post a Comment