DSD0: Calculate DSD0

In valentingar/ConFluxPro: A toolkit for soil gas analysis

Calculate DSD0

Description

Different functions to estimate soil diffusivity from the air-filled pore space.

Usage

DSD0_millington_quirk(AFPS, TPS = NULL, tortuosity = NULL)

DSD0_moldrup(AFPS, AFPS_100, b_campbell)

DSD0_currie(AFPS, a_currie = 1.9, b_currie = 1.4)

DSD0_linear(AFPS, a_lin, b_lin)

Arguments

AFPS	The air-filled porosity.
TPS	Total pore space
tortuosity	the tortuosity of the soil
AFPS_100	Air filled porosity at -100cm soil water matric head.
b_campbell	Campbell (1974) PSD index
a_currie, b_currie	fit parameter of Currie-style models
a_lin, b_lin	linear model coefficients

Details

• DSD0_millington_quirk() is of the form D_s / D_0 = \Xi \cdot \epsilon where \Xi is the tortuosity factor (tortuosity) calulcated as \Xi = \frac{\epsilon^{(10/3)}}{\Phi^2} ; \epsilon is the air-filled pore space (AFPS) and \Phi is the porosity (TPS). From Millington & Quirk (1961).

• DSD0_moldrup() is of the form D_s / D_0 = (2 \cdot \epsilon_{100}^3 + 0.04 \cdot \epsilon_{100}) \cdot (\frac{\epsilon}{\epsilon_{100}})^{(2 + \frac{3}{b_{campbell}})} where \epsilon_{100} is the air-filled pore space at a matric potential head of -100 cm and b_{campbell} is the slope of the water retention curve. From Moldrup et al. (2000).

• DSD0_currie() is of the form D_s / D_0 = a \cdot \epsilon^b where a and b are fit parameter of an exponential model. From Currie (1960) with default values (a=1.9; b=1.4)from Troeh (1982).

• DSD0_linear() is a linear model of form D_s / D_0 = a \cdot \epsilon + b.

References

Millington, R. J., & Quirk, J. P. (1961). Permeability of porous solids. In Transactions of the Faraday Society (Vol. 57, p. 1200). Royal Society of Chemistry (RSC). https://doi.org/10.1039/tf9615701200

Moldrup, P., Olesen, T., Schjønning, P., Yamaguchi, T., & Rolston, D. E. (2000). Predicting the Gas Diffusion Coefficient in Undisturbed Soil from Soil Water Characteristics. In Soil Science Society of America Journal (Vol. 64, Issue 1, pp. 94–100). Wiley. https://doi.org/10.2136/sssaj2000.64194x

Currie, J. A. (1960). Gaseous diffusion in porous media. Part 2. - Dry granular materials. In British Journal of Applied Physics (Vol. 11, Issue 8, pp. 318–324). IOP Publishing. https://doi.org/10.1088/0508-3443/11/8/303

Troeh, F. R., Jabro, J. D., & Kirkham, D. (1982). Gaseous diffusion equations for porous materials. In Geoderma (Vol. 27, Issue 3, pp. 239–253). Elsevier BV. https://doi.org/10.1016/0016-7061(82)90033-7

Examples

DSD0_millington_quirk(0.5,0.6)

valentingar/ConFluxPro documentation built on Dec. 1, 2024, 9:35 p.m.