R/pedotransfer_functions.R
ptfs.RdA set of pedotransfer functions for deriving Mualem - van Genuchten parameters from soil physical properties of soil horizons, such as soil texture, bulk density and carbon content.
hydpar_puh2(clay, silt, sand, bd, oc.pct = 0.5)
hydpar_hypres(clay, silt, bd, oc.pct = 0.1, topsoil = TRUE, humconv = 1.72)
hydpar_hypres_tab(texture, topsoil)
hydpar_wessolek_tab(texture)
hydpar_ff_b90(n = 1)Numeric vectors of clay, silt, sand in mass %.
Particle size ranges for clay, silt and sand correspond to <2, 2-63, and
63-2000 \(\mu m\). For hydpar_hypres, the particle
size limit between silt and sand should be 50 \(\mu m\).
Numeric vector of bulk density in g cm-3.
Numeric vector of organic carbon content in mass %.
Logical: Is the sample from the topsoil? Used in
hydpar_hypres_tab.
Conversion factor from oc.pct to organic matter percent.
Default: 1.72. Only for hydpar_hypres_tab.
Character vector of soil texture classes. For
hydpar_wessolek_tab classes according to KA5 (AG Boden 2005) have to
be provided. When using hydpar_hypres_tab, texture classes
according to FAO (1990) have to provided.
An integer value specifying the number of rows of the returned
data.frame (i.e. the number of repetitions of the MvG-Parameter set, only
for hydpar_ff_hamken).
A data.frame with the following variables:
Saturation water content fraction
Residual water content fraction
N parameter of the van Genuchten water retention function
M parameter of the van Genuchten water retention function
Alpha parameter of the van Genuchten water retention function (1/m)
Saturated hyraulic conductivity parameter of Mualem hydraulic conductivity function (mm/d)
Tortuosity parameter of Mualem hydraulic conductivity function
Function hydpar_puh2 derives Mualem - van Genuchten (MvG) parameters
using the regression functions developed by Puhlmann & von Wilpert (2011).
The equations of Wösten et al. (1999) are available via hydpar_hypres,
and their tabulated values for soil texture classes can be derived using the
function hydpar_hypres_tab. The table of MvG parameters from Wesselok
et al. (2009; Tab. 10) is accessible by hydpar_wessolek_tab. For this
function, soil texture classes after the German texture classification system
(KA5, AG Boden 2005) have to be provided. To derive hydraulic parameters of
forest floor horizons, the function hydpar_ff_b90 can be used. It
returns the single MvG parameter set for forest floor horizons reported by
Hammel & Kennel (2001) in their original LWF-Brook90 publication.
AG Boden (2005) Bodenkundliche Kartieranleitung Schweizerbart'sche Verlagsbuchhandlung, Stuttgart
Food and Agriculture Organisation (FAO) (1990) Guidelines for soil description FAO/ISRIC, Rome, 3rd edition
Hammel K & Kennel M (2001) Charakterisierung und Analyse der Wasserverfügbarkeit und des Wasserhaushalts von Waldstandorten in Bayern mit dem Simulationsmodell BROOK90. Forstliche Forschungsberichte München 185
Puhlmann H, von Wilpert K (2011) Testing and development of pedotransfer functions for water retention and hydraulic conductivity of forest soils. Waldökologie, Landschaftsforschung und Naturschutz 12, pp. 61-71
Wessolek G, Kaupenjohann M and Renger H (2009) Bodenphysikalische Kennwerte und Berechnungsverfahren für die Praxis. Bodenökologie und Bodengenese 40, Berlin, Germany
Woesten JHM, Lilly A, Nemes A, Le Bas C (1999) Development and use of a database of hydraulic properties of European soils. Geoderma 90, pp. 169-185
hydpar_puh2(clay = c(10,20), silt = c(40,20), sand = c(50,60), bd = c(1.6, 1.4))
#> ths thr alpha npar mpar ksat tort
#> 1 0.3700561 0.069 2.063483 1.245316 0.1969907 35.34026 -0.1221964
#> 2 0.3992240 0.069 8.156158 1.278638 0.2179176 108.53398 -1.4644501
hydpar_hypres(20,20,1.5,2)
#> ths thr alpha npar mpar ksat tort
#> 1 0.394632 0 5.462451 1.181339 0.1535029 364.6788 -3.61904
hydpar_hypres_tab(texture = c("C","MF"), topsoil = c(TRUE,FALSE))
#> ths thr alpha npar mpar ksat tort
#> 1 0.403 0.025 3.83 1.377 0.274 600 1.25
#> 2 0.412 0.010 0.82 1.218 0.179 40 0.50
hydpar_wessolek_tab(c("Us", "Ls2", "mSfS"))
#> ths thr alpha npar mpar ksat tort
#> 2 0.3946 0.0000 2.747 1.22393 0.1829598 355.26 -2.728
#> 1 0.4148 0.1406 4.052 1.32416 0.2448043 384.30 -2.067
#> 3 NA NA NA NA NA NA NA
hydpar_ff_b90(n = 5)
#> ths thr alpha npar mpar ksat tort
#> 1 0.848 0 98 1.191 0.1603694 98000 0.5
#> 1.1 0.848 0 98 1.191 0.1603694 98000 0.5
#> 1.2 0.848 0 98 1.191 0.1603694 98000 0.5
#> 1.3 0.848 0 98 1.191 0.1603694 98000 0.5
#> 1.4 0.848 0 98 1.191 0.1603694 98000 0.5