The SIX TENTHS Rule

That's right! The average velocity at any location in a stream can be estimated by measuring the velocity at six-tenths of the depth of the stream at that location. This is called the six-tenths rule.

If the stream is 3.2 meters deep, the average velocity at that spot can be estimated by measuring the velocity at 3.2 m times 0.6, which equals 1.92 m

Answer these questions.

1. At what depth should a velocity sensor be placed to estimate a stream's average velocity if it's 12.5 meters deep? meters 2. Same questions as above, but for a stream that's 2.0 meters deep. meters

Copyright © 2000 Geology Labs On-Line