hydrology_interception: Rainfall interception

In medfate: Mediterranean Forest Simulation

Rainfall interception

Description

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_erFactor(doy, pet, prec, Rconv = 5.6, Rsyn = 1.5)

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

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

Arguments

doy	Day of the year.
pet	Potential evapotranspiration for a given day (mm).
prec	Precipitation for a given day (mm).
Rconv, Rsyn	Rainfall rate for convective storms and synoptic storms, respectively, in mm/h.
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.
method	Rainfall interception method (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.

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_erFactor calculates the evaporation-to-rainfall ratio for input values of potential evapotranspiration and rainfall, while accounting for seasonal variation in rainfall intensity (mm/h). Default values Rconv = 5.6 and Rsyn = 1.5 come from Miralles et al. (2010).

Value

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

Function hydrology_erFactor returns a scalar with the evaporation-to-rainfall ratio.

Author(s)

Miquel De Cáceres Ainsa, CREAF

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.

Miralles DG, Gash JH, Holmes TRH, et al (2010) Global canopy interception from satellite observations. J Geophys Res 115:D16122. doi: 10.1029/2009JD013530.

See Also

spwb

Examples

#Load example plot plant data
data(exampleforestMED)

#Default species parameterization
data(SpParamsMED)

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

medfate documentation built on Aug. 29, 2023, 5:07 p.m.