Soil hydraulic pedotransfer functions and retention curves

SaxtonRawls: Saxton and Rawls (2006) Table 1 moisture regressions, density effects and conductivity from sand and clay fractions and percent organic matter. VanGenuchten: van Genuchten (1980) retention and Mualem conductivity. Identical to the Python arm morie.fn.soilhyd.

Usage

SaxtonRawls(sand, clay, om, density_factor = 1)

VanGenuchten(h, theta_r, theta_s, alpha, n, ks = NULL, pore_l = 0.5)

Arguments

sand, clay

Weight fractions.

om

Organic matter (percent).

density_factor

Density adjustment factor.

h

Suction (positive).

theta_r, theta_s

Residual and saturated water contents.

alpha, n

Van Genuchten parameters.

ks

Saturated conductivity.

pore_l

Pore-connectivity parameter.

Value

List.

References

Saxton, K. E. and Rawls, W. J. (2006). Soil water characteristic estimates by texture and organic matter for hydrologic solutions. Soil Science Society of America Journal 70, 1569-1578.

van Genuchten, M. Th. (1980). A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal 44, 892-898.

Examples

SaxtonRawls(0.4, 0.2, 2.5)$theta33
#> [1] 0.2796102
VanGenuchten(c(0, 100), 0.05, 0.45, 0.02, 1.5, ks = 10)$theta
#> [1] 0.4500000 0.3056936