der: Empirical Potential Evapotranspiration and Daily Drought...

Description Usage Arguments Details Author(s) References See Also Examples

Description

Calculates Daily Extraterrestrial radiation (DER) according to the formules indicated by FAO and Daily Potential Evapotranspiration (ET) according to Hargerves' formula and Drought Daily Index (DDI) and Daily Dew Point Temperature (TDEW)

Usage

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
DER(doy = 1, lat = 46, unit = "MJ_per_square_meter_per_day",
  vaporization_latent_heat = 2.45, divide_by_latent_heat = FALSE)

ET(doy = 1, lat = 46, vaporization_latent_heat = 2.45, Tn = 10,
  Tx = 20, Tmean = 14)

DDI(doy = 1, lat = 46, vaporization_latent_heat = 2.45, Tn = 10,
  Tx = 20, Tmean = 14, prec = 0, lag = 6, DDI_lim = c(0, 0.5, 1, 3),
  ops = "/")

TDEW(doy = 1, lat = 46, vaporization_latent_heat = 2.45, Tn = 10,
  Tx = 20, Tmean = 14, prec = 0, lag = 6, valmin_prec = 0.5,
  intercept_prec, intercept_noprec, coeff_prec, coeff_noprec, DDI_lim = NULL)

Arguments

doy

day of the year

lat

latitude expressed in degrees North

unit

output measurement unit

vaporization_latent_heat

water vaporization latent heat expressed in MJ per Kg. Default is 2.45.

divide_by_latent_heat

logical values. If TRUE unit is set equal to "Kg_per_square_meter_per_day". Default is FALSE.

prec

daily precipitation expressed in mm

Tx,Tn,Tmean

Daily Maximum, Minimun and Mean Temperature expressed in Celsius Degrees

DDI_lim

a vector in case DDI must returns numerical catagories or integer number. Default is NULL and DDI is returned as a continuous numerical value

ops

operation used for DDI computation. Default is "/"

lag

number of days used for calculation of DDI. See reference.

valmin_prec

precipitation threshold value under which no daily precipitation is considered. Default is 0.5 mm.

intercept_prec,intercept_noprec,coeff_prec,coeff_noprec

values for piecewise linear function for dew temperature correctio. See FAO method in the Reference.

Details

These functions implement the theory illustrated in the following paper: from http://onlinelibrary.wiley.com/doi/10.1002/met.258/abstract

Author(s)

Emanuele Cordano

References

See the URLs in DESCRIPTION files

See Also

air_humidity

Examples

1
# See examples in "air_humidity" function

ecor/RHUMIDITY documentation built on May 15, 2019, 8:52 p.m.