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medfate (version 2.2.1)

soil: Soil initialization

Description

Initializes soil parameters and state variables for its use in simulations.

Usage

soil(SoilParams, VG_PTF = "Toth", W = as.numeric(c(1)), SWE = 0)
# S3 method for soil
print(x, model="SX", ...)
redefineSoilLayers(SoilParams, widths = c(300, 700, 1000, 2000))

Arguments

SoilParams

A data frame of soil parameters (see an example in defaultSoilParams).

VG_PTF

Pedotransfer functions to obtain parameters for the van Genuchten-Mualem equations. Either "Carsel" (Carsel & Parrish 1988) or "Toth" (Toth et al. 2015).

W

A numerical vector with the initial relative water content of each soil layer.

SWE

Initial snow water equivalent of the snow pack on the soil surface (mm).

x

An object of class soil.

model

Either 'SX' or 'VG' for Saxton or Van Genuchten pedotransfer models.

widths

A numeric vector indicating the desired layer widths, in mm.

...

Additional parameters to print.

Value

Function soil returns a list of class soil with the following elements:

  • SoilDepth: Soil depth (in mm).

  • W: State variable with relative water content of each layer (in as proportion relative to FC).

  • Temp: State variable with temperature (in <U+00BA>C) of each layer.

  • Ksoil: Kappa parameter for infiltration.

  • Gsoil: Gamma parameter for infiltration.

  • dVec: Width of soil layers (in mm).

  • sand: Sand percentage for each layer (in percent volume).

  • clay: Clay percentage for each layer (in percent volume).

  • om: Organic matter percentage for each layer (in percent volume).

  • VG_alpha, VG_n, VG_theta_res, VG_theta_sat: Parameters for van Genuchten's pedotransfer functions, for each layer, corresponding to the USDA texture type.

  • Ksat: Saturated soil conductivity for each layer (estimated using function soil_saturatedConductivitySX.

  • macro: Macroporosity for each layer (estimated using Stolf et al. 2011).

  • rfc: Percentage of rock fragment content for each layer.

  • Kdrain: Saturated vertical hydraulic conductivity (mm/day) (i.e. how easy is deep drainage towards groundwater). Function soil estimates it as a function of soil saturated hydraulic conductivity, but should be parametrized as a function of bedrock material.

Details

Function print prompts a description of soil characteristics and state variables (water content and temperature) according to a water retention curve (either Saxton's or Van Genuchten's). Volume at field capacity is calculated assuming a soil water potential equal to -0.033 MPa. Parameter Temp is initialized as missing for all soil layers. Function redefineSoilLayers allows redefining soil layer widths of an input data frame of soil parameters.

References

Carsel, R.F., & Parrish, R.S. 1988. Developing joint probability distributions of soil water retention characteristics. Water Resources Research 24: 755<U+2013>769.

T<U+00F3>th, B., Weynants, M., Nemes, A., Mak<U+00F3>, A., Bilas, G., & T<U+00F3>th, G. 2015. New generation of hydraulic pedotransfer functions for Europe. European Journal of Soil Science 66: 226<U+2013>238.

Stolf, R., Thurler, A., Oliveira, O., Bacchi, S., Reichardt, K., 2011. Method to estimate soil macroporosity and microporosity based on sand content and bulk density. Rev. Bras. Ciencias do Solo 35, 447<U+2013>459.

See Also

soil_psi2thetaSX, soil_psi2thetaVG, spwb, defaultSoilParams

Examples

Run this code
# NOT RUN {
# Initializes soil
s = soil(defaultSoilParams())

# Prints soil characteristics according to Saxton's water retention curve
print(s, model="SX")

# Prints soil characteristics according to Van Genuchten's water retention curve
print(s, model="VG")

# }

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