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.

## 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))
```