A function to determine the modal suction, volume of drainable pores, structural index and stability ratio
using the high-energy-moisture-characteristics (HEMC) method by Pierson & Mulla (1989), which is used to analyze
the aggregate stability. Before using hemc(), the user may estimate the parameters of the Modified van
Genuchten's Model through the function fitsoilwater5().
Usage
hemc(x, theta_R, theta_S, alpha, n, b1, b2,
graph = TRUE, from = 1, to = 30,
xlab = expression(Psi ~ (J~kg^{-1})),
ylab = expression(d ~ theta/d ~ Psi), ...)
Arguments
x
a vector containing matric potential values.
theta_R
a numeric vector of length two containing the parameter values in the following orde: fast and slow.
theta_S
a numeric vector of length two containing the parameter values in the following orde: fast and slow.
alpha
a numeric vector of length two containing the parameter values in the following orde: fast and slow.
n
a numeric vector of length two containing the parameter values in the following orde: fast and slow.
b1
a numeric vector of length two containing the parameter values in the following orde: fast and slow.
b2
a numeric vector of length two containing the parameter values in the following orde: fast and slow.
graph
logical; if TRUE (default), a graphical solution is shown).
from
the lower limit for the x-axis
to
the lower limit for the x-axis
xlab
a label for the x-axis
ylab
a label for the y-axis
...
further graphical arguments
Value
A list of a two objects: 1) a matrix containing the Modal Suction, the Volume od Drainable Pores (VDP) and the Structural Index for
both, fast and slow wetting; and 2) the value of Stability Ratio.
References
Pierson, F.B.; Mulla, D.J. (1989). An Improved Method for Measuring Aggregate Stability of a Weakly
Aggregated Loessial Soil. Soil Sci. Soc. Am. J., 53:1825--1831.