KvapFun {spsh}

Calculates the Isothermal Water Vapour Conductivity

Description

Calculates the isothermal vapour conductivity as a function of modelled volumetric air content. Different models are implemented enabling the calculation of the relative gas diffusion coefficient (Ds/Do), based on different expressions for an effective tortuosity.

Usage

KvapFun(
  p,
  por = p[2],
  retFun = NA,
  theta = NA,
  model = "MQ61",
  Temp = 20,
  m = 3,
  pF = seq(-3, 7, length = 501),
  output = "log10",
  ...
)

Arguments

p

vector of soil hydraulic property model parameters, cf resp soil hydraulic property model for details.

por

skalar value giving the fraction of a porous' media porosity [ - ]( value between [0, 1] ), defaults to the saturated water content.

retFun

soil hydraulic property function has to be specified if models PMQ, TPM or TPEM are used, necessary to calculate the air content at h = 100 cm for the parameter eps100.

theta

vector of numerical volumetric water contents [0,1] at which the air content is to be calculated.

model

Implemented models (specify as character):

B	Buckingham (1904)
P	Penman (1940)
MQ60	Millington and Quirck (1960)
MQ61	Millington and Quirck (1961)
GS	Grable and Siemer (1968)
L	Lai et al. (1976)
PMQ	Moldrup et al. (1997)
TPM	Moldrup et al. (2004)
TPEM	Moldrup et al. (2005)

Temp

Soil tempereature [ deg C ], defaults to 20.

m

PMQ model parameter, default m = 3.

pF

monotonically increasing pF values, defined as log10(| pressure head [ cm ]).

output

Defaults to log10 indicates the isothermal vapour conductivity is returned as log₁₀(conductivity), if ouput != log10, the output will be in non-transformed values.

...

more arguments to be passed to retFun

Details

More reading on the models reference is made to suggested in (Weber et al. 2019)

Author(s)

Tobias KD Weber , [e-mail]

References

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.

Buckingham, E. (1904). Contributions to Our Knowledge of the Aeration Status of Soils, Bulletin 25, USDA Bureau of Soils, Washington, DC.

Grable, A.R.; Siemer, E.G. (1968).Effects of Bulk Density, Aggregate Size, and Soil Water Suction on Oxygen Diffusion, Redox Potentials, and Elongation of Corn Roots. Soil Sci. Soc. Am. Proc., 32, pp. 180-186. <doi:10.2136/sssaj1968.03615995003200020011x>.

Lai, S.H.; Tiedje J.M.; Erickson, E. (1976). In situ Measurement of Gas Diffusion Coefficient in Soils. Soil Sci. Soc. Am. J., 40, pp. 3-6. <doi:10.2136/sssaj1976.03615995004000010006x>.

Moldrup, P.; Olesen, T.; Rolston, D.E.; and Yamaguchi, T. (1997). Modeling Diffusion and Reaction in Soils: Vii. Predicting Gas and Ion Diffusivity in Undisturbed and Sieved Soils. Soil Science. 162 (9): pp. 632-640.

Moldrup, P.; Olesen, T.; Yoshikawa, S.; Komatsu, T.; and Rolston, D.E. (2004). Three-Porosity Model for Predicting the Gas Diffusion Coefficient in Undisturbed Soil. Soil Sci. Soc. Am. J. 68 (3).pp. 750-759. <doi:10.2136/sssaj2004.7500>.

Moldrup, P.; Olesen, T.; Yoshikawa, S.; Komatsu, T.; and Rolston, D.E. (2005). Predictive-Descriptive Models for Gas and Solute Diffusion Coefficients in Variably Saturated Porous Media Coupled to Pore-Size Distribution: II. Gas Diffusivity in Undisturbed Soil. Soil Sci., 170, pp. 854-866. <doi:10.1097/01.ss.0000196768.44165.1f>.

Millington, R.J.; Quirk, J.P. (1960). Millington, R. J., and Quirk. J.M. Transport in porous media. pp. 97-106. In: F.A. Van Beren, et al. (ed.) Trans. Int. Congr. Soil Sci., 7 th, Vol. 1, Madison, Wl. 14-24 Aug. 1960. Elsevier, Amsterdam.

Millington, R.J.; Quirk, J.P. (1961). Permeability of Porous Solids. Trans. Faraday Soc., 1961, 57, pp. 1200-1207. <doi:10.1039/TF9615701200>.

Penman, H.L. (1940). Gas and vapour movements in the soil: I. The diffusion of vapours through porous solids. J. Agric. Sci., 30: pp. 437-462. <doi:10.1017/S0021859600048164>.

Xu, X; Nieber, J.L. Gupta, S.C. (1992). Compaction Effect on the Gas Diffusion Coefficient in Soils. Soil Sci. Soc. Am. J.,56, pp. 1743-1750. <doi:10.2136/sssaj1992.03615995005600060014x>.

Examples

# | pressure head |
pF <- seq(-3, 7, length = 201)
h <- 10^pF
# van Genuchten-Mualem model parameters
p <- c(0.08, .42, .05, 1.5, 100, .5)
# calculate soil hydraulic property values
shypL <- shypFun.01110(p, h)
# clculate the isothermal vapour conductivity
kvap <- KvapFun(p, por = p[2], retFun = NA, theta = shypL$theta, model = "MQ61", 
                Temp = 20, m = 3, pF, output = "log10")