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Silt fences: an economical technique for measuring hillslope soil erosion
Robichaud, P.R.; Brown, R.E. 2002.
Silt fences: an economical technique for measuring hillslope soil erosion.
Gen. Tech. Rep. RMRS-GTR-94.
Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 24 p.
Keywords: silt fence, erosion, erosion rate, sediment, measurement techniques, monitoring
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Abstract:
Measuring hillslope erosion has historically been a costly, time-consuming practice. An easy to
install low-cost technique using silt fences (geotextile fabric) and tipping bucket rain gauges to measure
onsite hillslope erosion was developed and tested. Equipment requirements, installation procedures, statistical
design, and analysis methods for measuring hillslope erosion are discussed. The use of silt fences is
versatile; various plot sizes can be used to measure hillslope erosion in different settings and to determine
effectiveness of various treatments or practices. Silt fences are installed by making a sediment trap facing
upslope such that runoff cannot go around the ends of the silt fence. The silt fence is folded to form a pocket
for the sediment to settle on and reduce the possibility of sediment undermining the silt fence. Cleaning out
and weighing the accumulated sediment in the field can be accomplished with a portable hanging or platform
scale at various time intervals depending on the necessary degree of detail in the measurement of
erosion (that is, after every storm, quarterly, or seasonally). Silt fences combined with a tipping bucket rain
gauge provide an easy, low-cost method to quantify precipitation/hillslope erosion relationships. Trap efficiency
of the silt fences is greater that 90 percent, thus making them suitable for use in estimating hillslope erosion.
Moscow FSL publication no. 2002a
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