USFS Portable Bedload
Trap
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The USFS Portable Bedload Trap was developed for representative
sampling initiation of gravel motion and coarse bedload transport
rates in wadable gravel and cobble bed mountain streams. The trap
is 0.3 m wide, 0.2 m high and has a 0.9 m long trailing net with a
3.5 mm mesh width. The trap can be quickly installed on a stream
bottom with little disturbance of the bed and can be operated by
1-3 persons over a wide range of flow. For sampling, the trap is
temporarily fastened onto ground plates anchored into the stream
bottom. Usually the traps are deployed in sets of 5 to 6 traps on
riffles or runs in mountain gravel-bed streams. Sampling time is
usually one hour and facilitates representative samples of a wide
range of transport rates (up to 7 orders of magnitude) and bedload
particle sizes (4-90 mm). This capability for representative
sampling provides valuable bedload data-sets suitable for
performing initial motion computations.
406-001 USFS Bedload
Trap 8 lbs.
