Format Weather Data for Use in epicrop — format

Formats an existing data.frame of weather data for use in cropsim. Only the data necessary for use in the model is returned and the columns are renamed to values expected by the model. The data are assumed to be on a daily time-step. For converting sub-daily weather data to daily, see cropgrowdays::daily_mean().

Usage

format_wth(wth, date, temp, rhum, rain, tmin, tmax, lat, lon)

Arguments

wth: A data.frame object containing the weather data for formatting.
date: The column name indicating the field containing the date values.
temp: The column name indicating the field containing the average daily temperature values.
rhum: The column name indicating the field containing the average daily relative humidity.
rain: The column name indicating the field containing the total daily rainfall.
tmin: The column name indicating the field containing the minimum daily temperature (optional).
tmax: The column name indicating the field containing the maximum daily temperature.
lat: The column name indicating the field containing the latitude of the observation data (optional).
lon: The column name indicating the field containing the longitude of the observation data (optional).

Value

An epicrop.wth object, a data frame compatible with a data.table::data.table, suitable for use in epicrop.

Details

Required values

Weather data must be a daily time-step and contain the following values,

full date including year, month and day,
average daily temperature,
average daily relative humidity,
total daily rainfall

Optional values

The following values are optional and the model can be run by default without them.

average minimum daily temperature (only used if simple_wetness == FALSE)
average maximum daily temperature (only used if simple_wetness == FALSE)
Latitude (only used if simple_wetness == FALSE and for mapping outputs)

Longitude (only used for mapping outputs)

Field Name	Value
YYYYMMDD	Date as Year Month Day (ISO8601)
DOY	Consecutive day of year, commonly called "Julian date"
TEMP	Mean daily temperature (°C)
TMIN	Daily minimum temperature (˚C)
TMAX	Daily maximum temperature (˚C)
RHUM	Mean daily relative humidity (%)
RAIN	Mean daily rainfall (mm)
LAT	Latitude of area of interest
LON	Longitude of area of interest.

Author

Adam H. Sparks, adamhsparks@gmail.com

Examples

# Get weather data from the POWER API, using the `get_wth()` function,
# this is for example purposes only as it is NOT necessary to reformat
# the data provided by `get_wth()`.

library(nasapower)
w <- get_power(
  lonlat = c(121.25562, 14.6674),
  dates = c("2000-06-30", "2000-12-31"),
  community = "AG",
  pars = c(
    "T2M",
    "T2M_MIN",
    "T2M_MAX",
    "RH2M",
    "PRECTOTCORR"
  ),
  temporal_api = "DAILY"
)
#> No encoding supplied: defaulting to UTF-8.
#> No encoding supplied: defaulting to UTF-8.

format_wth(
  wth = w,
  date = "YYYYMMDD",
  temp = "T2M",
  rhum = "RH2M",
  rain = "PRECTOTCORR",
  tmin = "T2M_MIN",
  tmax = "T2M_MAX",
  lat = "LAT",
  lon = "LON"
)
#>        YYYYMMDD   DOY  TEMP  TMIN  TMAX  RHUM  RAIN     LAT      LON
#>          <Date> <int> <num> <num> <num> <num> <num>   <num>    <num>
#>   1: 2000-06-30   181 26.02 23.34 28.76 88.53 11.01 14.6674 121.2556
#>   2: 2000-07-01   182 25.29 23.86 27.78 92.20 23.12 14.6674 121.2556
#>   3: 2000-07-02   183 26.13 23.54 29.90 86.01 17.34 14.6674 121.2556
#>   4: 2000-07-03   184 25.50 24.28 27.23 94.16 29.08 14.6674 121.2556
#>   5: 2000-07-04   185 25.81 24.50 27.56 92.42 13.01 14.6674 121.2556
#>  ---                                                                
#> 181: 2000-12-27   361 24.46 22.90 26.28 92.49 21.15 14.6674 121.2556
#> 182: 2000-12-28   362 24.64 23.32 27.28 91.92  6.01 14.6674 121.2556
#> 183: 2000-12-29   363 24.58 22.51 27.90 90.79  5.49 14.6674 121.2556
#> 184: 2000-12-30   364 25.31 22.84 28.84 86.25  2.07 14.6674 121.2556
#> 185: 2000-12-31   365 24.47 21.63 28.63 87.83  3.45 14.6674 121.2556