Comment: 18:56 - 20:29 (01:33)
Source: Annenberg/CPB Resources - Earth Revealed - 19. Running Water I: Rivers, Erosion and Deposition
Keywords: river, "U.S. Army Corps of Engineers", "Red Eye Crossing", "river channel", WES, "Waterways Experiment Station", dredge, modeling, discharge, "bed load", "flow pattern", "point bar", mapping, sedimentation
Our transcription: The Army Corps of Engineers would like to minimize the amount of dredging necessary to keep the channel clear.
At the core of their study is a scale model of the River.
Graded crushed coal is used to represent the bed material.
By studying how the coal moves as water is discharged through the model, the Corp's engineers hope to better understand the Red Eye Crossing problem, and come up with solutions.
Each experiment with the model has a known fixed amount of water discharged.
Water fills the channel and is allowed to run for a measured length of time.
Almost immediately the bed load begins to move.
Confetti thrown on the water surface during the experiment clearly indicates the water's flow patterns through the Crossing.
The white beads are another indicator of how the model is performing.
The beads build up where expected, at the place where in nature itself, the point bar exists.
This indicates the model simulates nature accurately.
Periodically, the model is drained and its sediment is carefully mapped.
This detailed mapping gives engineers a better understanding of sedimentation processes in the River.
Geology School Keywords