Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.5194/hess-26-5849-2022 |
Licence  |
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| Title (Primary) | Technical note: A sigmoidal soil water retention curve without asymptote that is robust when dry-range data are unreliable |
| Author | de Rooij, G.H. |
| Source Titel | Hydrology and Earth System Sciences |
| Year | 2022 |
| Department | BOSYS |
| Volume | 26 |
| Issue | 22 |
| Page From | 5849 |
| Page To | 5858 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Data and Software links | https://doi.org/10.5281/zenodo.7271284 |
| Abstract | In a recently introduced parameterization for the soil water retention curve (SWRC) with a sigmoid wet branch and a logarithmic dry branch, the matric potential at the junction point of the sigmoid and the logarithmic branch (hj) was a fitting parameter, while that at oven dryness (hd) was derived from the fitting parameters. The latter is undesirable, especially if reliable data in the dry range are limited. Therefore, an alternative is presented in which shape parameter α instead of hd is a derived parameter, and hd can be fitted or fixed. The resulting relationship between α and hj is such that it prevents correct fits for hj. Fortunately, an expression for hj is found that allows it to be replaced by α as a fitting parameter. The corresponding parameter space is well behaved and has fewer internal bounds defined by restraining relationships between parameters than the space for hj as a fitting parameter. The few available values of hj in the literature are in line with those according to the new expression. The reformulated SWRC is fitted to data of 21 soils by shuffled complex evolution. The paper gives the main features of an accompanying open source fitting code. The curves fit the data well, except for some clayey soils. A theoretical value of hd performs well for a wide range of soils. The new SWRC simplifies to an earlier junction model of the SWRC based on a well known power-law SWRC if α is very large. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=26829 |
| de Rooij, G.H. (2022): Technical note: A sigmoidal soil water retention curve without asymptote that is robust when dry-range data are unreliable Hydrol. Earth Syst. Sci. 26 (22), 5849 - 5858 10.5194/hess-26-5849-2022 |
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