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.
KvapFun(
p,
por = p[2],
retFun = NA,
theta = NA,
model = "MQ61",
Temp = 20,
m = 3,
pF = seq(-3, 7, length = 501),
output = "log10",
...
)vector of soil hydraulic property model parameters, cf resp soil hydraulic property model for details.
skalar value giving the fraction of a porous' media porosity [ - ]( value between [0, 1] ), defaults to the saturated water content.
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.
vector of numerical volumetric water contents [0,1] at which the air content is to be calculated.
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) |
Soil tempereature [ deg C ], defaults to 20.
PMQ model parameter, default m = 3.
monotonically increasing pF values, defined as log10(| pressure head [ cm ]).
Defaults to log10 indicates the isothermal vapour conductivity is returned as (conductivity), if ouput != log10,
the output will be in non-transformed values.
more arguments to be passed to retFun
More reading on the models reference is made to suggested in Weber.2019spsh
Weber.2019spsh 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>.
# NOT RUN {
# | 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")
# }
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