(Table 1). There was a small difference in FT groundwater levels, with 10 cm and 7 cm in the higher and
lower moisture replicates, respectively, while C levels were both 10 cm. This final comparison should
provide an upper bound on the uncertainties in results for individual experiments of this study.
Equations used to quantify the differences between results for the pairs of replicated experiments
were the same for FT and C comparisons. The dimensional difference in each quantity for corresponding
FT bins can be expressed as
∆FT = FT - FTrep
(1)
where subscript "rep" indicates replicate, and the dimensionless percentage difference in FT quantities is
FT - FTrep
∆FT / FT =
.
(2)
FT
Results of comparisons using (1) and (2) are given in Table 11 for mean, time weighted, median, and
maximum sediment concentration, sediment load, total sediment transport, L2 and Linf norms at 0.3L and
0.7L, and average maximum width and depth. ∆FT and ∆C are expressed in Table 11 in the same units as
the original quantities, g/L for concentrations, g/min for load, kg for total transport, and cm for norms,
width, and depth.
Low moisture experiment 6 replicates showed good agreement in FT concentrations, total
transport, and norms at 0.3L. However, differences in the C replicates are generally large, especially in
the norms, with lower soil weight and higher flow yielding significantly more erosion. We offer the
interpretation that reduced soil moisture negates reduced soil weight and increased applied flow in the FT,
but not in C where changes in soil moisture are less important. High soil moisture experiment 4 and its
replicate indicate greatly increased FT concentrations and sediment load at higher moisture. Cross-
sectional changes were not as large in the FT, and ∆C quantities were generally small. Changes in soil
moisture of several percent by volume can greatly affect the erosion rate following FT. High soil
moisture experiment 4light comparisons indicate generally small dimensional changes between the
replicates, with concentrations differing by < 3 g/L and cross-section measures by < 0.5 cm. Percentage
changes can be large for parameters where the quantity being measured is small. The larger soil moisture
replicate produced small, but consistent increases in all FT and C quantities. These replicate comparisons
confirm our general observation that experimental results converge as parameter variability decreases,
and verify that tight parameter control within experimental series will permit quantitative comparisons of
results. However, even with tightly controlled experiments, small differences in results are expected
between replicates that for small quantities may result in large percentage changes.
Very Low Moisture Experiment
Our results have shown that a FT cycle has primary effects on subsequent flow-induced erosion
for soil moistures ranging from 1739% by volume, and that these effects increase with soil moisture
11
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