van Genuchten Water Retention Curve

van Genuchten Water Retention Curve

Usage

get_vg_hydraulic_head(theta, theta_r, theta_s, alpha, gamma_s)

Arguments

theta

volumetric water content

theta_r

residual water content

theta_s

saturated water content

alpha

scaling parameter (reciprocal of air entry pressure, units of 1/length)

gamma_s

curve shape, dimensionless

Details

See: Pan, T., Hou, S., Liu, Y., & Tan, Q. (2019). Comparison of three models fitting the soil water retention curves in a degraded alpine meadow region. Scientific Reports, 9(1), 18407.

Examples

# example code
library(units)
theta <- 0.24
theta_r <- 0.15
theta_s <- 0.25
alpha <- set_units(0.008, "1/cm") # should have units of 1/length
gamma_s <- 10.4
get_vg_hydraulic_head(theta, theta_r, theta_s, alpha, gamma_s)
#> -102.2389 [cm]