ClimMobTools (version 0.2-7)

ETo: Evapotranspiration

Description

Compute evapotranspiration using the Blaney-Criddle method

Usage

ETo(object, day.one = NULL, span = NULL, lat = NULL, Kc = 1,
  p = NULL)

Arguments

object

a numeric vector of geographic coordinates (lonlat) or an array with two dimensions containing the temperature data; 1st dimension contains the day temperature and 2nd dimension the night temperature. When lonlat is used, the function makes a call to nasapower::get_power to fetch and concatenate environmental data from NASA POWER (https://power.larc.nasa.gov/)

day.one

a vector of class 'Date' for the starting date to capture the environmental data

span

an integer or a vector with integers for the duration of the timespan to be captured

lat

a vector for the latitude (in Decimal degrees)

Kc

a numeric value for the crop factor for water requirement

p

optional, a numeric value (from 0 to 1) used if lat is not given, representing the mean daily percentage of annual daytime hours for different latitudes

Value

The evapotranspiration in mm/day

Examples

# NOT RUN {
 
library("ClimMobTools")
library("nasapower")

# random geographic locations around bbox(11, 12, 55, 58)
lonlat <- data.frame(lon = runif(10, 11, 12),
                     lat = runif(10, 55, 58))

# random planting dates around 2018-05-15 and 2018-05-20
pdates <- as.integer(runif(10, 17666, 17670))
pdates <- as.Date(pdates, origin = "1970-01-01")

# the evapotranspiration in the first 50 days after planting
ETo(lonlat,
    day.one = pdates,
    span = 50,
    lat = lonlat[["lat"]])
# }
# NOT RUN {
# }