A pH-based pedotransfer function for scaling saturated hydraulic conductivity reduction: improved estimation of hydraulic dynamics in HYDRUS
Article
Article Title | A pH-based pedotransfer function for scaling saturated hydraulic conductivity reduction: improved estimation of hydraulic dynamics in HYDRUS |
---|---|
ERA Journal ID | 35068 |
Article Category | Article |
Authors | Ali, Aram (Author), Biggs, Andrew J. W. (Author), Simunek, Jirka (Author) and Bennett, John McL. (Author) |
Journal Title | Vadose Zone Journal |
Journal Citation | 18 (1), pp. 1-13 |
Article Number | 190072 |
Number of Pages | 13 |
Year | 2019 |
Place of Publication | United States |
ISSN | 1539-1663 |
Digital Object Identifier (DOI) | https://doi.org/10.2136/vzj2019.07.0072 |
Web Address (URL) | https://acsess.onlinelibrary.wiley.com/doi/10.2136/vzj2019.07.0072 |
Abstract | Hydraulic conductivity is a key soil property governing agricultural production and is thus an important parameter in hydrologic modeling. The pH scaling factor for saturated hydraulic conductivity (Ks) reduction in the HYDRUS model was reviewed and evaluated for its ability to simulate Ks reduction. A limitation of the model is the generalization of Ks reduction at various levels of electrolyte concentration for different soil types, i.e., it is not soil specific. In this study, a new generalized linear regression model was developed to estimate Ks reduction for a larger set of Australian soils compared with three American soils. A nonlinear pedotransfer function was also produced, using the Levenberg–Marquardt optimization algorithm, by considering the pH and electrolyte concentration of the applied solution as well as the soil clay content. This approach improved the estimation of the pH scaling factor relating to Ks reduction for individual soils. The functions were based on Ks reduction in nine contrasting Australian soils using two sets of treatment solutions with Na adsorption ratios of 20 and 40; total electrolyte concentrations of 8, 15, 25, 50, 100, 250, and 500 mmolc L−1; and pH values of 6, 7, 8, and 9. A comparison of the experimental data and model outputs indicates that the models performed objectively well and successfully described the Ks reduction due to the pH. Further, a nonlinear function provided greater accuracy than the generalized function for the individual soils of Australia and California. This indicates that the nonlinear model provides an improved estimation of the pH scaling factor for Ks reduction in specific soils in the HYDRUS model and should therefore be considered in future HYDRUS developments and applications. |
Keywords | solution pH, hydraulic conductivity, pedotransfer function, modelling, scaling factor, HYDRUS |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 300207. Agricultural systems analysis and modelling |
300202. Agricultural land management | |
Byline Affiliations | Centre for Sustainable Agricultural Systems |
Department of Natural Resources and Mines, Queensland | |
University of California, United States | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q5q85/a-ph-based-pedotransfer-function-for-scaling-saturated-hydraulic-conductivity-reduction-improved-estimation-of-hydraulic-dynamics-in-hydrus
Download files
163
total views90
total downloads1
views this month1
downloads this month