CLC number:
On-line Access: 2024-08-27
Received: 2023-10-17
Revision Accepted: 2024-05-08
Crosschecked: 2019-07-08
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Qian Zhai, Chen-feng Zhang, Guo-liang Dai, Xue-liang Zhao. Effect of segments of soil-water characteristic curves on the estimated permeability function using statistical methods[J]. Journal of Zhejiang University Science A, 2019, 20(8): 627-633.
@article{title="Effect of segments of soil-water characteristic curves on the estimated permeability function using statistical methods",
author="Qian Zhai, Chen-feng Zhang, Guo-liang Dai, Xue-liang Zhao",
journal="Journal of Zhejiang University Science A",
volume="20",
number="8",
pages="627-633",
year="2019",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.A1900166"
}
%0 Journal Article
%T Effect of segments of soil-water characteristic curves on the estimated permeability function using statistical methods
%A Qian Zhai
%A Chen-feng Zhang
%A Guo-liang Dai
%A Xue-liang Zhao
%J Journal of Zhejiang University SCIENCE A
%V 20
%N 8
%P 627-633
%@ 1673-565X
%D 2019
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.A1900166
TY - JOUR
T1 - Effect of segments of soil-water characteristic curves on the estimated permeability function using statistical methods
A1 - Qian Zhai
A1 - Chen-feng Zhang
A1 - Guo-liang Dai
A1 - Xue-liang Zhao
J0 - Journal of Zhejiang University Science A
VL - 20
IS - 8
SP - 627
EP - 633
%@ 1673-565X
Y1 - 2019
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.A1900166
Abstract: The water flow in unsaturated soil is controlled mainly by the soil-water characteristic curve (SWCC) and the coefficient of permeability of the soil, both of which are functions of the soil suction. Experimental measurement of both the SWCC and permeability function is time consuming and costly. As a result, indirect methods for estimating the permeability function from the SWCC are commonly accepted by researchers. Among different indirect methods for the estimation, statistical methods have been proven to be rigorous and reliable. They provide discrete results for the permeability function corresponding to different soil suctions, and the estimations are dependent on the division of SWCC segments. In this paper, we adopt two approaches with different procedures to estimate the permeability function using statistical methods. The first approach evenly divides the SWCC in the domain of volumetric water content, and the second evenly divides the SWCC in the domain of matric suction. The effects of the SWCC segments on the permeability function estimated from the SWCC (including unimodal and bimodal curves) using both approaches are investigated and discussed. A minimum number of 40 segments is recommended for the estimation. We recommend that the SWCC should be divided within the matric suction domain rather than the volumetric water content domain for the estimation of the permeability function using statistical methods.
The Authors investigated the required number of divisions to obtain a good performance of the equation in the estimation of the unsaturated hydraulic conductivity. The study will benefit engineers in practice since the direct measurement of the unsaturated hydraulic conductivity is tedious and time-consuming.
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