calcEto {AquaBEHER} | R Documentation |
Calculates Penman-Monteith, Priestley Taylor and Hargreaves-Samani Potential Evapotranspiration using the method described by Allen et al, (1998)
calcEto(data, method = "PM", crop = "short", Zh = NULL)
data |
A dataframe containing the required weather variables with the following columns:
|
method |
The formulation used to compute Eto; default is |
crop |
Either |
Zh |
Height of wind speed measurement in meters. |
Penman-Monteith: If all variables of Tmax, Tmin, Rs, either U2 or Uz, and either RHmax and RHmin or RH or Tdew are available and crop surface (short or tall) is specified, the Penman-Monteith FAO56 formulation is used (Allen et al. 1998).
Priestley-Taylor: If all variables of Tmax, Tmin, Rs, and either RHmax and RHmin or RH or Tdew are available, the Priestley-Taylor formulation is used (Priestley and Taylor, 1972).
Hargreaves-Samani: If only Tmax and Tmin are available, the Hargreaves-Samani formulation is used for estimating reference crop evapotranspiration (Hargreaves and Samani, 1985).
A list containing:
ET.Daily
: Daily estimations of reference crop
evapotranspiration (mm/day).
Ra.Daily
: Daily estimations of extraterrestrial radiation
(MJ/m^2/day).
Slope.Daily
: Daily estimations of slope of vapor pressure
curve (kPa/°C).
ET.type
: Type of the estimation obtained.
Allen, R.G., L.S. Pereira, D. Raes, and M. Smith. 1998. Crop evapotranspiration-Guidelines for Computing Crop Water requirements FAO Irrigation and Drainage Paper 56. FAO, Rome 300: 6541.
Allen, R. G. 2005. The ASCE standardized reference evapotranspiration equation. Amer Society of Civil Engineers.
Guo, D., Westra, S., & Maier, H. (2016). An R package for modelling actual, potential and reference evapotranspiration. Environmental Modelling & Software, 78, 216-224. doi:10.1016/j.envsoft.2015.12.019.
Hargreaves, G.H., & Samani, Z.A. (1985). Reference crop evapotranspiration from ambient air temperature. American Society of Agricultural Engineers.
Priestley, C., & Taylor, R. (1972). On the assessment of surface heat flux and evaporation using large-scale parameters. Monthly Weather Review, 100(2), 81-92.
climateData
, calcWatBal
,
calcSeasCal
## Load sample data:
data(climateData)
PET.HS <- calcEto(climateData, method = "HS")
## Load sample data:
data(AgroClimateData)
PET.PM <- calcEto(AgroClimateData, method = "PM", crop = "short")