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.

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.

See also

spwb

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))