کلیدواژهها
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one-dimensional, three-dimensional, nonlinear curve-fitting method of two-term equation, nonlinear
curve-fitting method of three-term equation , characteristic time
method, quasi-exact implicit, quantile–quantile, simplified characteristic time method, Sharma, SWIG.
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چکیده
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Recently, a novel approach with excellent performance based on the concept of
the characteristic infiltration time, the characteristic time method (CTM), is proposed
to infer soil sorptivity (S) and saturated hydraulic conductivity (Ks) from one dimensional
(1D) cumulative infiltration. The current work provides a simplified
version of the CTM, called the SCTM, by eliminating the necessity of the iteration
method used in CTM and providing a similar accuracy as the original method
when estimating S and Ks. We used both synthetic and experimental data to evaluate
SCTM in comparison with the original CTM, as well as Sharma (SH) and curve fitting
methods. In the case of synthetically simulated infiltration experiments, the
predicted S and Ks values showed an excellent agreement with their theoretical values,
with Nash–Sutcliffe (E) values higher than 0.9 and RMSE values of 0.11 cm h1/2
and 0.35 cm h–1, respectively. In the case of experimental data, the SCTM showed E
values larger than 0.73 and RMSE values of 0.64 cm h1/2 and 0.35 cm h–1, respectively.
The accuracy and the robustness of SCTM was comparable with the original
CTM when applied on synthetic infiltration curves as well as on experimental
data. Similar to the original CTM, the simplified approach also does not require the
knowledge of the time validity, which is needed when using approaches based on
Philip’s infiltration theory. The method is applicable to infiltrations with durations
from 15 min to 24 h. The supplemental material presents the calculation of S and Ks
using SCTM in an Excel spreadsheet.
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