Package 'cropwatMUL'

Representative multilocation input data

Description

A synthetic example generated with rnorm() for demonstrating the required input structure. The object is a named list containing climate, soil, and crop data frames.

Usage

cropwat_example_data

Format

A list with three components:

climate

Monthly maximum and minimum temperature, rainfall, coordinates, altitude, wind speed, and radiation coefficient for three fictional locations.

soil

Soil texture and available water capacity for each location.

crop

Planting date, growth-stage duration, crop coefficients, and maximum rooting depth for potato.

Source

Simulated specifically for cropwatMUL; not observed data.

---

Estimate reference evapotranspiration from temperature

Description

Estimates daily reference evapotranspiration using the FAO-56 Penman–Monteith equation with vapour pressure and solar radiation inferred from minimum and maximum air temperature.

Usage

pm_temp_estimated(
  tmax,
  tmin,
  lat,
  doy,
  altitude_m = 0,
  u2 = 2,
  krs = 0.16,
  albedo = 0.23
)

Arguments

tmax	Numeric maximum air temperature in degrees Celsius.
tmin	Numeric minimum air temperature in degrees Celsius.
lat	Numeric latitude in decimal degrees.
doy	Integer day of year, from 1 to 365 or 366.
altitude_m	Numeric elevation above mean sea level in metres.
u2	Numeric wind speed at 2 m height in m s-1.
krs	Numeric temperature-based radiation adjustment coefficient.
albedo	Numeric surface albedo.

Value

A numeric vector of reference evapotranspiration in mm day-1.

Examples

pm_temp_estimated(25, 15, 25.7, 15, altitude_m = 1000)

---

Run a CROPWAT-inspired multilocation simulation

Description

Reads climate, soil, and crop worksheets from an Excel workbook and calculates daily, dekadal, monthly, and seasonal crop-water and irrigation indicators for one crop across multiple locations.

Usage

run_cropwat_one_crop_multilocation(
  input_file,
  crop_name = "Potato",
  output_year = NULL,
  irrigation_efficiency = 0.7,
  critical_depletion = 0.35,
  root_initial_m = 0.15,
  u2 = 2,
  krs = 0.16,
  altitude_m = 0,
  initial_depletion_mm = 0
)

Arguments

input_file	Path to an Excel workbook containing the required sheets.
crop_name	Crop name appearing in the crop worksheet.
output_year	Optional simulation year. Defaults to the planting year.
irrigation_efficiency	Fractional field application efficiency.
critical_depletion	Fraction of total available water that triggers irrigation.
root_initial_m	Initial effective rooting depth in metres.
u2	Wind speed at 2 m height in m s-1 when not supplied in the workbook.
krs	Radiation adjustment coefficient when not supplied in the workbook.
altitude_m	Elevation in metres when not supplied in the workbook.
initial_depletion_mm	Initial root-zone water depletion in millimetres.

Value

A named list containing input data, settings, and simulation outputs.

Examples

input <- system.file("extdata", "cropwat_example.xlsx", package = "cropwatMUL")
if (nzchar(input)) {
  result <- run_cropwat_one_crop_multilocation(input, crop_name = "Potato")
  result$summaries
}

---

Estimate monthly effective rainfall

Description

Applies the USDA Soil Conservation Service monthly effective rainfall relationship used in CROPWAT-style calculations.

Usage

usda_scs_effective_rain(P)

Arguments

P	Numeric monthly rainfall in millimetres.

Value

Numeric effective rainfall in millimetres.

Examples

usda_scs_effective_rain(c(50, 150, 300))

---

Validate a cropwatMUL input workbook

Description

Checks worksheet names, required columns, monthly completeness, location matching, crop-stage parameters, and the principal numeric constraints required by the simulation.

Usage

validate_cropwat_input(input_file, crop_name = NULL)

Arguments

input_file	Path to the input Excel workbook.
crop_name	Optional crop to validate.

Value

Invisibly returns TRUE; otherwise stops with an informative error.

Examples

input <- system.file("extdata", "cropwat_example.xlsx", package = "cropwatMUL")
if (nzchar(input)) validate_cropwat_input(input, "Potato")

---

Export cropwatMUL results

Description

Writes one Excel workbook and location-specific text files from an object returned by run_cropwat_one_crop_multilocation().

Usage

write_cropwat_outputs(
  results,
  output_dir,
  prefix = "CROPWAT_one_crop_multiple_locations"
)

Arguments

results	A cropwatMUL result object.
output_dir	Character path to the directory in which outputs will be written. This argument must be supplied explicitly. The directory is created recursively when it does not already exist.
prefix	File-name prefix.

Value

Invisibly returns paths to the Excel workbook and text directory.

Examples

input <- system.file(
  "extdata",
  "cropwat_example.xlsx",
  package = "cropwatMUL"
)

if (nzchar(input)) {
  result <- run_cropwat_one_crop_multilocation(
    input_file = input,
    crop_name = "Potato"
  )

  output_dir <- tempfile("cropwatMUL-example-")
  dir.create(output_dir)

  output_files <- write_cropwat_outputs(
    results = result,
    output_dir = output_dir,
    prefix = "potato_example"
  )

  output_files

  
}

---