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Measuring floodwater in ND

April 2019 (approx.)

Detailed Description

The USGS uses an Acoustic Doppler Current Profiler (ADCP) to measure flooding in Fargo, North Dakota. The ADCP measures water currents with sound, using a principle of sound waves called the Doppler effect. The ADCP works by transmitting "pings" of sound at a constant frequency into the water. As the sound waves travel, they ricochet off particles suspended in the moving water, and reflect back to the instrument.


Public Domain.