shypFun.01310 {spsh}

van Genuchten-Mualem trimodal Soil Hydraulic Propterty Model

Description

trimodal van Genuchten-Mualem functions for the retention and hydraulic conductivity curves (Durner 1994).

Usage

shypFun.01310(p, h)

Arguments

p

vector of the 9 van Genuchten-Mualem model parameters, order is sensitve and has to be given as:

thr	residual water water content [cm cm-3]
ths	saturated water water content [cm cm-3]
alf1	van Genuchten alpha [cm-3]
n1	van Genuchten n [-]
w1	fraction of the first modality [-], w2 is internally computed as w2 = 1-w1
alf2	van Genuchten alpha of the second modality[cm-3]
n2	van Genuchten n of the second modality [-]
w2	fraction of the second modality [-], w3 is internally computed as w3 = 1-w1-w2, in resFun ensures w3 >=0
alf3	van Genuchten alpha of the third modality[cm-3]
n3	van Genuchten n of the third modality [-]
Ks	saturated conductivity [cm d-1]
tau	exponent of Se in the capillary conductivity model, sometimes denoted in the literature as l [-]

h

pressure heads [cm] for which the corresponding retention and conductivity values are calculated.

Details

The function solves analytically the spec. water capacity function and integral to the capillary bundle model.

Value

returns a list with calculations at specified h:

theta

calculated volumetric moisture content

Se

calculated saturation

cap

specific water capacity function

psd

pore size distribution

Kh

Hydraulic conductivity values

Author(s)

Tobias KD Weber , [e-mail]

References

Durner W (1994). “Hydraulic conductivity estimation for soils with heterogeneous pore structure.” Water Resources Research, 30(2), 211–223. ISSN 0043-1397.

See Also

Weber TK, Durner W, Streck T, Diamantopoulos E (2019). “A modular framework for modelling unsaturated soil hydraulic properties over the full moisture range.” Water Resources Research. ISSN 0043-1397, doi: 10.1029/2018WR024584.
Weber TKD, Iden SC, Durner W (2017). “Unsaturated hydraulic properties of Sphagnum moss and peat reveal trimodal pore-size distributions.” Water Resources Research, 53(1), 415–434. ISSN 0043-1397, doi: 10.1002/2016WR019707.
Weber TKD, Iden SC, Durner W (2017). “A pore-size classification for peat bogs derived from unsaturated hydraulic properties.” Hydrology and Earth System Sciences, 21(12), 6185–6200. ISSN 1607-7938, doi: 10.5194/hess-21-6185-2017.

Examples

p <- c("thr" = 0.1, "ths" = 0.4, alf1 = .5, "n1" = 3,
       "w1" = .5, "alf2" = 0.01, "n2" = 2, 
       "w2" = .3, "alf3" = 0.01, "n3" = 1.6, 
       "Ks" = 100, "tau" = .5)
h <- 10^seq(-2, 6.8, length = 197)
shyp.L <- shypFun.01310(p, h)