hemc: High-Energy-Moisture-Characteristics Aggregate Stability

Description Usage Arguments Value Author(s) References See Also Examples

View source: R/hemc.R

Description

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

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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.

Author(s)

Anderson Rodrigo da Silva <[email protected]>

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.

See Also

fitsoilwater5

Examples

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hemc(x = seq(1, 30), theta_R = c(0.27, 0.4), theta_S = c(0.65, 0.47), 
	alpha = c(0.1393, 0.0954), n = c(6.37, 7.47), 
	b1 = c(-0.008421, -0.011970), b2 = c(0.0001322, 0.0001552))

# End (Not run)

soilphysics documentation built on May 30, 2017, 2:49 a.m.