FLOOD01191

• County: Statewide
• Title: Laboratory Data on Course-Sediment Transport for Bedload-Sampler Calibrations
• Date: 1/1/1987
• Prepared By: USGS
• Floodplain - Doc Type: Educational/Technical/Reference Information

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0 40 80 120 160 200 240
TIME, IN MINUTES

Figure 19. Temporal records of bedload-transport rates, qpI measured at weigh pan 4 during A, run 1 and B, run 3, with the
6.5-mm bed material. The mean transport rale for the part of the record depicled in each graph is given in the upper left corner.
Discontinuities in the record represent weigh-pan dumps.

Particle-size distributions of all samples collected dur-
ing the uniform.bed-malerial runs, as well as size distribu-
tions of the raw unprocessed material, recombinations of
samples from stock piles of the excluded (reject) material,
and the retained material placed in the flume. are presented
in table 6. The distributions are expressed bolh in terms of
the whole sample (designated "all sizes" in table 6) and the
part coarser than the finest separation size (the part to which
sampled and measured rates pertain). Because many analy-
ses were made during runs with the bed-material mixture,
only size distributions defined near the first and last day of
each run with the mixture are given in table 6. Change in
size with time of operation can be assessed by referring to
Ihe day number of each distribution.
Particle-size data from runs with the uniform bed ma-
terials are compiled only in tabular form. However, the size
distributions of all streambed, weigh-pan, and Y-diffusor
samples from the mixture runs are available on magnetic
media (see Availability of Data, inside back cover) in a data
file named PARTSIZE999RA.

Sampled Bedload Transport

Except for run 4 with the 23.5-mm material, samples
collected during runs with uniform bed materials ordinarily
were not analyzed to define their size distribution. How-
ever, most unanalyzed samples were wet sieved to deter-
mine the percentage of material finer than the specified
separation size. For unsieved samples, the percentage of
material finer than the separation size for each sampler was

taken as the average from sieved samples collected during
the run with thai sampler. For run 4 with 23.5-mm material
and for runs with the mixture, all samples were completely
sized either by wet sieving or by a combinalion of wet and
dry sieving (see table 3). Available size information was
used, in turn, to determine, for each sample, the transport
rate(s) of the size range(s) of interest.

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EXPLANA lION

08

0.6

02

- - - - - Run 3, 2.1-mm bed material
- - - - - - - Run 3, 6.5--mm bed material
Run 1, 19.9-mm bed material

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TRANSPORT RATE. IN POUNDS PER SECOND PER FOOT

Figure 20. Cumulative relative-frequency distribulions of
bedload-transport rates measured at weigh pan 4.

14 Laboratory Data on Coarse-Sediment Transport for Bedload-Sampler Calibrations