soilevap: Soil evapotranspiration

In ilyamaclean/ecohydrotools: hydrogical modelling for ecological applications with R

Description

Soil evapotranspiration

Usage

soilevap(cre, sm, cover = 0.5, topratio = 0.5)

Arguments

cre	Crop reference evapotranspiration as returned by cre.hourly() or cre.daily()
sm	Soil water fraction
cover	Fraction of vegetation cover
topratio	Ratio of root water uptake from top layer relative to bottom layer (1 = all from top layer, 0 = all form bottom layer)

Details

soilevap calculates soil evapotranspiration from crop reference evapotranspiration.

As the soil water fraction decreases below the saturation value, evaporation from bare soil is usually assumed to continue at the potential rate until the water content decreases below a critical value. Thereafter, evaporation is assumed to decrease linearly with decreasing water content, vanishing to zero when water content is low. The paramater cover aportions the ratio of evapotranspiration to bare soil evaporation. The paramater topratio aportions evapotranspiration between the top and bottom layer and depends on the chosen soil layer depths and root depths.

Value

a list of with two elements: top evaporation and evapotranspiration from the top soil layer, btm evapotranspiration from the bottom layer. Units are as for CRE

See Also

cre.hourly() cre.daily()

Examples

sm <- c(0:100) / 100
plot(soilevap(1, sm, cover = 1, surface = 1)$top ~ sm, type = "l")
plot(soilevap(1, sm, cover = 0, surface = 1)$top ~ sm, type = "l")

ilyamaclean/ecohydrotools documentation built on June 10, 2019, 5:45 a.m.