Comment: 21:47 - 22:44 (00:57)
Source: Annenberg/CPB Resources - Earth Revealed - 20. Running Water II: Landscape Evolution
Keywords: "Old River", dam, "U.S. Army Corps of Engineers", "Old River Control Project", river, "Mississippi River", "Atchafalaya River", "flow velocity", flow-rate, discharge, sediment, scouring, equilibrium, gradient
Our transcription: A small device is lowered into the water to measure velocity.
These measurements are made along various parts of the River to calculate discharge.
Using this information, flow predictions are made, and the gates are raised or lowered accordingly.
But the amount of water flow is not the only factor that needs to be considered in keeping the Mississippi in place.
Although the Atchafalaya takes water from the Mississippi, it leaves most of the sediment behind.
In response, the Atchafalaya scours its own channel, acquiring enough new sediment to restore its equilibrium.
The effect of the scouring also deepens the Atchafalaya bed providing an even steeper route for the Mississippi.
Geology School Keywords