Rescaled capillary saturation function by Iden and Durner (2014)
Scap(suc, par.shp, modality = c("uni"), suc.negativ = FALSE)
Suction/pressure heads. Negative if suc.negativ = TRUE
named parameter in list or vector
pore size distribution ('uni' or 'bi')
set TRUE if suction/pressure heads are negative and FALSE if positive
additional for bimodal ('bi') pore size distribution: w2 [-]: weigthing between pore space distribution alfa2 [1/L]: van Genuchten parameter alfa for second pore space distribution n2 [-]: van Genuchten parameter n for second pore space distribution m2 [-]: shape parameter (m = 1-(1/n2) if missing)
Scap(h) = (Gamma(h)- Gamma(h0))/(1 - Gamma(h0))
Gamma descripes the capillary saturation function. Here the saturation function of van Genuchten is used:
gamma(h) = (1/(1 + -suc * alfa)^n)^m (see also Sat
)
Iden, S., Durner, W. (2014). Comment to Simple consistent models for water retention and hydraulic conductivity in the complete moisture range by A. Peters. Water Resour. Res. 50, 7530<U+2013>7534.
Schneider, M., & Goss, K. U. (2012). Prediction of the water sorption isotherm in air dry soils. Geoderma, 170, 64-69.