Green-Ampt horizontal flow time

This function models saturated horizontal flow from a saturated surface into a soil profile. The assumptions are the same as in the Green-Ampt equation, except that there is no effect of gravity because all flow is assumed to be horizontal. The equation is:

$$t = \frac{F^2}{2 \Delta \theta K_{sat} (h_b - h_0)}$$

Usage

get_greenampt_horiz_time(theta_0, theta_s, Fcum, Ksat, h_b, h_0)

Arguments

theta_0

Soil volumetric water content prior to event

theta_s

Soil porosity

Fcum

cumulative infiltration in mm water equivalent

Ksat

Saturated hydraulic conductivity

h_b

Hydraulic head at soil surface boundary

h_0

Hydraulic head in soil prior to event

Value

Returns the time at which a cumulative amount of infiltration occurs.

Examples

library(units)
theta_0 <- 0.2 # unitless
theta_s <- 0.35 # unitless
Fcum <- set_units(20, "mm") # depth
Ksat <- set_units(0.2, "cm/h") # length / time
h_b <- set_units(6, "ft") # hydraulic head (length)
h_0 <- set_units(-10, "cm") # hydraulic head (length)
times <- get_greenampt_horiz_time(theta_0, theta_s, Fcum, Ksat, h_b, h_0)