Abstract
The determination of soil hydraulic properties is laborious and expensive, especially in large-scale applications. One often used substitute for measured hydraulic properties are pedotransfer function (PTFs) estimates. Most PTFs, however, are statistical models that tend to produce biased results for data outside their –often limited– calibration databases. In addition, most PTFs have been established on data derived from temperate regions causing the question whether such models are applicable to soils in tropical regions. This work aimed to evaluate the performance of the Splintex PTF to predict the hydraulic functions for sandy and clayey soils from several tropical and subtropical Brazilian datasets. Splintex is somewhat unique in that it is based on physical principles using a modification of the Arya-Paris method while allowing the estimation of van Genuchten parameters from limited data. In addition, Splintex has an option to include measured soil water retention points, in principle allowing it to produce accurate estimates for a variety of soils. Estimates by Splintex were compared with the empirical Rosetta PTF, which also has an option to use one (or two) retention points. Estimates by both PTFs were compared to observed retention data and field capacity, available water capacity, hydraulic conductivity, and diffusivity using metrics such as Pearson correlation (r), mean absolute error (MAE) and root mean square error (RMSE). Both Splintex and Rosetta yielded similar results and sometimes produced significant biases in estimated quantities. In the majority of cases it appears that Splintex produced somewhat better estimates than the 2001 version of Rosetta, indicating that Splintex is a viable, physically-based, alternative to estimating hydraulic properties.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 261-272 |
| Number of pages | 12 |
| Journal | Soil and Tillage Research |
| Volume | 174 |
| DOIs | |
| State | Published - Dec 1 2017 |
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Keywords
- Pedofunction
- Soil hydraulic properties
- Soil water retention curve
ASJC Scopus subject areas
- Agronomy and Crop Science
- Soil Science
- Earth-Surface Processes
Cite this
SPLINTEX : A physically-based pedotransfer function for modeling soil hydraulic functions. / da Silva, Alessandra Calegari; Armindo, Robson André; dos Santos Brito, Alexsandro; Schaap, Marcel.
In: Soil and Tillage Research, Vol. 174, 01.12.2017, p. 261-272.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - SPLINTEX
T2 - A physically-based pedotransfer function for modeling soil hydraulic functions
AU - da Silva, Alessandra Calegari
AU - Armindo, Robson André
AU - dos Santos Brito, Alexsandro
AU - Schaap, Marcel
PY - 2017/12/1
Y1 - 2017/12/1
N2 - The determination of soil hydraulic properties is laborious and expensive, especially in large-scale applications. One often used substitute for measured hydraulic properties are pedotransfer function (PTFs) estimates. Most PTFs, however, are statistical models that tend to produce biased results for data outside their –often limited– calibration databases. In addition, most PTFs have been established on data derived from temperate regions causing the question whether such models are applicable to soils in tropical regions. This work aimed to evaluate the performance of the Splintex PTF to predict the hydraulic functions for sandy and clayey soils from several tropical and subtropical Brazilian datasets. Splintex is somewhat unique in that it is based on physical principles using a modification of the Arya-Paris method while allowing the estimation of van Genuchten parameters from limited data. In addition, Splintex has an option to include measured soil water retention points, in principle allowing it to produce accurate estimates for a variety of soils. Estimates by Splintex were compared with the empirical Rosetta PTF, which also has an option to use one (or two) retention points. Estimates by both PTFs were compared to observed retention data and field capacity, available water capacity, hydraulic conductivity, and diffusivity using metrics such as Pearson correlation (r), mean absolute error (MAE) and root mean square error (RMSE). Both Splintex and Rosetta yielded similar results and sometimes produced significant biases in estimated quantities. In the majority of cases it appears that Splintex produced somewhat better estimates than the 2001 version of Rosetta, indicating that Splintex is a viable, physically-based, alternative to estimating hydraulic properties.
AB - The determination of soil hydraulic properties is laborious and expensive, especially in large-scale applications. One often used substitute for measured hydraulic properties are pedotransfer function (PTFs) estimates. Most PTFs, however, are statistical models that tend to produce biased results for data outside their –often limited– calibration databases. In addition, most PTFs have been established on data derived from temperate regions causing the question whether such models are applicable to soils in tropical regions. This work aimed to evaluate the performance of the Splintex PTF to predict the hydraulic functions for sandy and clayey soils from several tropical and subtropical Brazilian datasets. Splintex is somewhat unique in that it is based on physical principles using a modification of the Arya-Paris method while allowing the estimation of van Genuchten parameters from limited data. In addition, Splintex has an option to include measured soil water retention points, in principle allowing it to produce accurate estimates for a variety of soils. Estimates by Splintex were compared with the empirical Rosetta PTF, which also has an option to use one (or two) retention points. Estimates by both PTFs were compared to observed retention data and field capacity, available water capacity, hydraulic conductivity, and diffusivity using metrics such as Pearson correlation (r), mean absolute error (MAE) and root mean square error (RMSE). Both Splintex and Rosetta yielded similar results and sometimes produced significant biases in estimated quantities. In the majority of cases it appears that Splintex produced somewhat better estimates than the 2001 version of Rosetta, indicating that Splintex is a viable, physically-based, alternative to estimating hydraulic properties.
KW - Pedofunction
KW - Soil hydraulic properties
KW - Soil water retention curve
UR - http://www.scopus.com/inward/record.url?scp=85028420271&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85028420271&partnerID=8YFLogxK
U2 - 10.1016/j.still.2017.07.011
DO - 10.1016/j.still.2017.07.011
M3 - Article
AN - SCOPUS:85028420271
VL - 174
SP - 261
EP - 272
JO - Soil and Tillage Research
JF - Soil and Tillage Research
SN - 0167-1987
ER -