Sad {SoilHyP}

Relative saturation function

Description

Relative saturation function for adsorptive water storage described by a piecwise linear function (Iden and Durner, 2014).

Usage

Sad(suc, par.shp, modality = c("uni"), suc.negativ = TRUE)

Arguments

suc

Suction/pressure heads. Negative if suc.negativ = TRUE

par.shp

named parameter of soil hydraulic properties in list or vector (see details)

modality

pore size distribution ('uni' or 'bi')

suc.negativ

set TRUE if suction/pressure heads are negative and FALSE if positive

Details

par.shp:

ths [-]: saturated water content
thr [-]: residual water content
alfa [1/L]: van Genuchten shape parameter
n [-]: van Genuchten shape parameter
h0 [L]: suction at water content of 0 (i.e. oven dryness) (h0 = 10^6.8 if missing, corresponding to oven dryness at 105°C (Schneider and Goss, 2012))

par.shp (additional for bimodal (modality = 'bi')):

alfa2 [1/L]: van Genuchten parameter alfa for second pore space distribution
n2 [-]: van Genuchten parameter n for second pore space distribution

Author(s)

Ullrich Dettmann

References

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, 7530–7534.

Schneider, M., & Goss, K. U. (2012). Prediction of the water sorption isotherm in air dry soils. Geoderma, 170, 64-69.