Publication Details

Category Software Publication
DOI 10.5281/zenodo.7271284
Licence creative commons licence
Title (Primary) Fitting the parameters of the RIA parameterization of the soil water retention curve (1.1)
Version 1.1
Author de Rooij, G.H.
Source Titel Zenodo
Year 2022
Department BOSYS
Topic T5 Future Landscapes
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.
linked UFZ text publications
Persistent UFZ Identifier
de Rooij, G.H. (2022):
Fitting the parameters of the RIA parameterization of the soil water retention curve (1.1)
Version: 1.1 Zenodo 10.5281/zenodo.7271284