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  California Water Science Center

Configuration of a Gravel Dune

This graph shows the change in bed elevation at a single point as measured by sonar. When gravel bedforms migrate downstream, they can move a distance of one meter in a minute. To interpret the stationary sonar record as bedforms, imagine that the bedforms move from right to left.

A large-mouth pressure-difference bedload sampler was used to collect bedload samples within 0.5 m of the sonar point. The sampling point was established 0.5 m streamward of the sonar point to ensure that the sampled rates were representative of the bedform movement. (Photo [131kb] of Bedload sampling near sonar point )

Bedform where bedload samples were taken

Bedload samples corresponding to the dashed lines are shown below. The vertical scale bars are 10 centimeters or 4 inches long.

Bedload samples

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Page Last Modified: Wednesday, 05-Oct-2011 15:14:50 EDT