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

Function to calculate the soil water content based on the van Genuchten's (1980) formula:

*θ = θ_R + (θ_S - θ_R)(1 + (α x)^n)^{-m}*

1 2 |

`x` |
the matric potential. |

`theta_R` |
the residual water content. |

`theta_S` |
the water content at saturation. |

`alpha` |
a scale parameter of the van Genuchten's formula. |

`n` |
a shape parameter in van Genuchten's formula. |

`m` |
a shape parameter in van Genuchten's Formula. Default is |

`saturation.index` |
logical; if FALSE (default) the outcome is the soil water content, otherwise the saturation index is returned. |

The the soil water content or the saturation index (a value between 0 and 1).

Anderson Rodrigo da Silva <anderson.agro@hotmail.com>
(code adapted from the function swc(), package *soilwater* (Cordano *et al*., 2012).)

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

Mualem, Y. (1976). A new model for predicting the hydraulic conductivity
of unsaturated porous media. *Water Resources Research*, 12:513-522.

1 2 3 4 5 6 7 8 9 10 11 | ```
# example 1
soilwater(x = 0.1, theta_R = 0.06, theta_S = 0.25, alpha = 21, n = 2.08)
curve(soilwater(x, theta_R = 0.06, theta_S = 0.25, alpha = 21, n = 2.08))
# example 2 (punctual predictions)
p <- seq(0, 1, length.out = 10)
m <- soilwater(x = p, theta_R = 0.06, theta_S = 0.25,
alpha = 21, n = 2.08)
points(m ~ p, type = "b", col = "red")
# End (not run)
``` |

```
Loading required package: rpanel
Loading required package: tcltk
Package `rpanel', version 1.1-4: type help(rpanel) for summary information
Loading required package: MASS
Loading required package: tkrplot
---
soilphysics version 3.1
Warning messages:
1: no DISPLAY variable so Tk is not available
2: loading Rplot failed
[1] 0.1371055
```

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.