Rainfall interception

Function hydrology_rainInterception calculates the amount of rainfall intercepted daily by the canopy, given a rainfall and canopy characteristics. Two canopy interception models are currently available: the sparse Gash (1995) model and the Liu (2001) model. In both cases the current implementation assumes no trunk interception.

Usage

hydrology_rainfallIntensity(month, prec, rainfallIntensityPerMonth)

hydrology_rainInterception(Rainfall, Cm, p, ER = 0.05, model = "Gash1995")

hydrology_interceptionPlot(
  x,
  SpParams,
  ER = 0.05,
  gdd = NA,
  throughfall = FALSE,
  model = "Gash1995"
)

Arguments

month: Month of the year (from 1 to 12).
prec: Precipitation for a given day (mm).
rainfallIntensityPerMonth: A vector with twelve positions with average intensity of rainfall (in mm/h) for each month.
Rainfall: A numeric vector of (daily) rainfall.
Cm: Canopy water storage capacity.
p: Proportion of throughfall (normally 1 - c, where c is the canopy cover).
ER: The ratio of evaporation rate to rainfall rate.
model: Rainfall interception model (either "Gash1995" or "Liu2001").
x: An object of class spwbInput.
SpParams: A data frame with species parameters (see SpParamsMED and SpParamsMED).
gdd: Growth degree days (in Celsius).
throughfall: Boolean flag to plot relative throughfall instead of percentage of intercepted rainfall.

Value

Function hydrology_rainInterception returns a vector of the same length as Rainfall containing intercepted rain values.

Function hydrology_rainfallIntensity returns a scalar with the rainfall intensity.

Details

Function hydrology_rainInterception can accept either vectors or scalars as parameters Cm, p and ER. If they are supplied as vectors they should be of the same length as Rainfall.

Function hydrology_rainfallIntensity estimates the rainfall intensity (mm/h) for input values of rainfall and seasonal variation in rainfall intensity (mm/h).

References

Liu (2001). Evaluation of the Liu model for predicting rainfall interception in forests world-wide. - Hydrol. Process. 15: 2341-2360.

Gash (1979). An analytical model of rainfall interception by forests. - Quarterly Journal of the Royal Meteorological Society.

Gash et al. (1995). Estimating sparse forest rainfall interception with an analytical model. - Journal of Hydrology.

Author

Miquel De Cáceres Ainsa, CREAF

Examples

#Load example plot plant data
data(exampleforest)

#Default species parameterization
data(SpParamsMED)

#Draw rainfall interception for two values of the E/R ratio
hydrology_interceptionPlot(exampleforest, SpParamsMED, ER = c(0.05, 0.2))