Package 'CropWat'

Compute cycle period extend during the year

Description

Compute cycle period extend during the year

Usage

calc_isCycle(cp, DatesR, sowing_date = cp$sowing_date)

Arguments

cp	Crop parameters (See get_crop_params)
DatesR	A vector of continuous lubridate::Date If NULL, the calculation is limited to the crop cycle of the plant
sowing_date	Sowing date in format "MM-DD"

Value

A vector of logical of the crop cycle for each day of the year.

Examples

DatesR <- seq(as.Date("2010-03-01"), as.Date("2010-10-31"), by = "1 day")
isCycle <- calc_isCycle(get_crop_params("SB2023-soja"), DatesR)
plot(isCycle)

---

Compute crop parameters time series from crop parameters pivot points

Description

These functions compute the following parameters:

Usage

calc_Kc(cp, DatesR = NULL, sowing_date = cp$sowing_date)

calc_RAW(TAW, p)

calc_TAW(
  cp,
  AWC,
  soil_depth,
  DatesR = NULL,
  sowing_date = cp$sowing_date,
  root_depth = calc_root_depth(cp, soil_depth, DatesR, sowing_date)
)

calc_p(cp, DatesR = NULL, sowing_date = cp$sowing_date)

calc_root_depth(cp, soil_depth, DatesR = NULL, sowing_date = cp$sowing_date)

Arguments

cp	Crop parameters (See get_crop_params)
DatesR	A vector of continuous lubridate::Date If NULL, the calculation is limited to the crop cycle of the plant
sowing_date	Sowing date in format "MM-DD"
TAW	Total Available Water (mm). See calc_TAW
p	fraction of Readily Available Water time series. See calc_p
AWC	Available Water Capacity (mm)
soil_depth	Soil depth (m)
root_depth	Root depth time series (m). See calc_root_depth

Details

• Calc_Kc: crop coefficient $K_c$

• calc_p: critical depletion fraction $p=RAW/TAW$

• calc_root_depth: root depth in m

• calc_RAW: Readily Available Water (RAW) in mm

• calc_TAW: Total Available Water (TAW) in mm

For calc_TAW, parameters cp, year, and sowing_date are useless if root_depth is provided.

Value

A vector of the parameter for each day of the crop cycle or the period defined by DatesR.

Examples

# Compute Kc for the crop cycle
Kc <- calc_Kc(get_crop_params("SB2023-soja"))
plot(Kc, type = "l")

# Compute Kc for a given period (less than one year)
# with default sowing date defined in crop parameters
DatesR <- seq(as.Date("2010-03-01"), as.Date("2010-10-31"), by = "1 day")
Kc <- calc_Kc(get_crop_params("SB2023-soja"), DatesR = DatesR)
plot(Kc, type = "l")

# Compute Kc for a given period with user defined sowing date
Kc <- calc_Kc(get_crop_params("FAO-MAIZE"),
              DatesR = DatesR,
              sowing_date = "05-01")
plot(Kc, type = "l")

---

Compute relative yield

Description

Compute relative yield

Usage

calc_relative_yield(ETc, ETc_adj, ky)

calc_yield_stagewise(ETc, ETc_adj, cp)

calc_yield_for_cycle(cycle_id, cw_output, cp)

Arguments

ETc	vector of maximum evapotranspiration of the crop considered, for the whole season (mm.day-1)
ETc_adj	vector of actual evapotranspiration of the crop considered, for the whole season (mm.day-1)
ky	yield response factor (-)
cp	parameters of the crop (vector)
cycle_id	numeric identifier of the crop cycle considered.
cw_output	A tibble with at least 4 columns: ETc, ETc_adj, cycle_id, isCycle

Value

calc_relative_yield returns the relative yields for the period considered. calc_yield_stagewise returns a named vector with the relative yield for each stage (compared to biomass accumulation during the stage) and for the whole cycle. calc_yield_for_cycle returns a named vector with cycle_id, relative_yield_cycle, and ⁠relative_yield_{stage}⁠ (for stage in (ini, dev, mid, end)) and relative_yield_cycle_stagewise for the crop cycle considered.

Functions

• calc_relative_yield(): Compute relative yield that depends on water stress for a given period. Reference: Crop Yield Response to Water. FAO Irrigation and Drainage Paper 66 (2012), equation 1.

• calc_yield_stagewise(): Compute relative yield that depends on water stress at each growth stage. Reference: Garg, N. K., and Sushmita M. Dadhich. "A proposed method to determine yield response factors of different crops under deficit irrigation using inverse formulation approach." Agricultural Water Management 137 (2014): 68-74., equation 3.

• calc_yield_for_cycle(): Compute relative yield for a given crop cycle directly over the whole cycle and using the stagewise method.

Examples

example("CW_run_simulation", "CropWat")

---

Create CropWat model input

Description

Create CropWat model input

Usage

CW_create_input(
  crop,
  DatesR,
  ETo,
  P,
  soil_depth,
  AWC,
  cp = get_crop_params(crop),
  sowing_date = cp$sowing_date
)

Arguments

crop	The code of the crop
DatesR	Simulation period (vector of lubridate::Date)
ETo	Potential Evaporation (mm/day)
P	Precipitation (mm/day)
soil_depth	soil depth (mm)
AWC	Available Water Capacity (mm)
cp	crop parameter (vector)
sowing_date	sowing date at the format 'mm-dd'

Details

The crop cycle begins at the first matching sowing date in the simulation period. So, first time steps of simulation if are not in a crop cycle even if they occur during the crop cycle.

Value

A tibble containing the input times series.

Examples

# Import example climate dataset
data(ZH_3_clim)
str(ZH_3_clim)
# Selecting years 2010 and 2011
meteo <-
  ZH_3_clim[ZH_3_clim$Date >= as.Date("2010-01-01") & ZH_3_clim$Date <= as.Date("2011-12-31"), ]
# Create model input
cw_input <- CW_create_input("SB2023-soja",
                            DatesR = meteo$Date,
                            ETo = meteo$ETP,
                            P = meteo$Ptot,
                            soil_depth = 1.2,
                            AWC = 140)
str(cw_input)

plot(cw_input)

---

CropWat model state initiation

Description

CropWat model state initiation

Usage

CW_create_state(
  Dr = 0,
  cw_input = NULL,
  iTS = 1,
  isCycle = cw_input$isCycle[iTS],
  TAW = cw_input$TAW[iTS]
)

Arguments

Dr	Initial root zone depletion (-)
cw_input	Model input
iTS	Time step to pick up in cw_input for defining isCycle and TAW
isCycle	logical defining if the time step is in the crop cycle
TAW	Total Available Water (mm)

Value

A list with items:

• Dr: Root zone depletion (-)

• isCycle: logical indicating if the state stands during the crop cycle

• TAW: Total Available Water (m)

Examples

example(CW_create_input, "CropWat")

X <- CW_create_state(cw_input = cw_input)
str(X)

---

Retrieve the path of internal package data

Description

Retrieve the path of internal package data

Usage

CW_data(file)

Arguments

file

File name

Value

The path of the file stored in the package dataset

Examples

CW_data("crop_params.tsv")

---

Irrigation management functions

Description

Built-in irrigation management functions for use in CW_model. For custom irrigation strategies, see CW_irrig_fun_factory.

Usage

CW_irrig_0(X, input, Dr)

CW_irrig_Dr(X, input, Dr)

Arguments

X	Model state at previous time step
input	Model input for the current time step
Dr	Current soil moisture depletion

Value

The amount of the daily irrigation (m)

Functions

• CW_irrig_0(): simulates the absence of irrigation (returns 0 for all time steps).

• CW_irrig_Dr(): simulates an irrigation system that fills the soil's moisture depletion on a daily basis.

Examples

CW_irrig_0()

example(CW_create_state, "CropWat")
CW_irrig_Dr(X, cw_input[1, ], 0.1)
CW_irrig_Dr(X, cw_input[100, ], 0.1)

---

Irrigation management function factory

Description

This function is a helper for generating irrigation management based on thresholds calculated from fixed ratios of RAW and/or TAW. The generated threshold is computed as RAW_ratio * RAW + TAW_ratio * TAW, where RAW (calc_RAW) is the Readily Available Water and TAW (calc_TAW) is the Total Available Water in the root zone.

Usage

CW_irrig_fun_factory(
  RAW_ratio,
  TAW_ratio = 0,
  apply_Dr = FALSE,
  dates_irrig = NULL
)

Arguments

RAW_ratio	Numeric multiplier applied to RAW (Readily Available Water) for computing the irrigation trigger threshold. When soil depletion (Dr) exceeds this threshold, irrigation is triggered.
TAW_ratio	Numeric multiplier applied to TAW (Total Available Water) for computing the irrigation trigger threshold. Added to RAW_ratio * RAW to form the complete threshold. Default is 0.
apply_Dr	When the threshold is reached, should the irrigation dose fill the soil's moisture depletion? If TRUE, the irrigation dose will be equal to the current soil depletion (Dr), effectively refilling the soil to field capacity. If FALSE, the irrigation dose will be equal to the difference between the current soil depletion (Dr) and the threshold (Sd).
dates_irrig	vector of lubridate::Date when irrigation occurs (By default, irrigation is applied during the crop cycle)

Value

A function which computes the irrigation dose for the current day.

Examples

# An irrigation management function which triggers an irrigation when
# Dr < 0.5 * RAW with a dose filling until 0.5 * RAW
fun_irrig_half_RAW <- CW_irrig_fun_factory(0.5)

fun_irrig_half_RAW

str(as.list(environment(fun_irrig_half_RAW)))

---

Run CropWat model for one time step

Description

Run CropWat model for one time step

Usage

CW_model(X, input, FUN_IRRIG = CW_irrig_Dr, is_irrigable_day = TRUE)

Arguments

X	Initial state (See CW_create_state)
input	Model input (See CW_create_input)
FUN_IRRIG	Irrigation management function. Built-in options include those documented in CW_irrig (no irrigation, full depletion refill). Custom functions can be generated with CW_irrig_fun_factory.
is_irrigable_day	logical TRUE if an irrigation is applicable for this time step

Value

A named numeric vector of class "CW_model" with items:

• Ks: Water stress coefficient (0-1, where 1 = no stress)

• ETc_adj: Adjusted crop evapotranspiration (mm/day)

• Dr: Root zone depletion at the end of the time step (mm)

• Ir: Irrigation dose for the current day (mm)

The returned value has an attribute "state" which contains the final state of the model at the end of the day (See CW_create_state).

Examples

data(ZH_3_clim)
meteo <-
  ZH_3_clim[ZH_3_clim$Date >= as.Date("2010-01-01") & ZH_3_clim$Date <= as.Date("2010-12-31"), ]
cw_input <- CW_create_input("SB2023-soja",
                            DatesR = meteo$Date,
                            ETo = meteo$ETP,
                            P = meteo$Ptot,
                            soil_depth = 1.2,
                            AWC = 140)
X0 <- CW_create_state(cw_input = cw_input)
X1 <- CW_model(X0, cw_input[1, ])
str(X1)

---

Run a simulation with the CropWat model

Description

Run a simulation with the CropWat model

Usage

CW_run_simulation(X, cw_input, FUN_IRRIG = CW_irrig_Dr)

Arguments

X	Initial state (See CW_create_state)
cw_input	Model input (See CW_create_input)
FUN_IRRIG	Irrigation management function. Built-in options include those documented in CW_irrig (no irrigation, full depletion refill). Custom functions can be generated with CW_irrig_fun_factory.

Value

A tibble with the daily time series of the model output, with one row by time step and the following columns:

• DatesR: Dates of the simulation

• Ks: Water stress coefficient (0-1, where 1 = no stress)

• ETc_adj: Adjusted evapotranspiration (mm/day)

• ETc: Potential evapotranspiration (mm/day)

• Dr: Root zone depletion (mm)

• Ir: Irrigation (mm)

• cycle_id: Crop cycle identifier (i.e year number of sowing)

• isCycle: Indicator if the row belongs to a crop cycle (i.e between sowing and harvest)

It also has the following attributes:

• final_state: the final state of the model after the simulation

• relative_yield: a data.frame with the relative yield for each crop cycle, one row by cycle, with columns cycle_id, relative_yield_cycle, and relative_yield_stagewise, where the latter two are computed with calc_yield_for_cycle

Examples

example("CW_create_state", "CropWat")
cw_output <- CW_run_simulation(X, cw_input)
str(cw_output)

plot(cw_output, which = c("daily", "yields"))

---

Crop parameters

Description

• load_crop_params: load the parameters for all the crops

• get_crop_params: returns the parameters of a given crop

Usage

load_crop_params(file = CW_data("crop_params.tsv"))

get_crop_params(crop, crop_params = load_crop_params())

Arguments

file	Path of the table of crop parameters
crop	The code of the crop
crop_params	data.frame of crop parameters (See load_crop_params)

Details

The file to read should have the following columns and format:

• crop: crop code

• Lini: Length of initial stage of crop development

• Ldev: Length of crop development stage

• Lmid: Length of mid season

• Lend: Length of late season

• Kini: Initial Kc at the beginning of the crop cycle during Lini days (-)

• Kmax: Maximum Kc during Lmid day of the cycle (-)

• Kend: Final Kc at the end of the cycle (-)

• Zini: Initial root depth at the beginning of the crop cycle (m)

• Zend: Final root depth at the end of the crop cycle (m)

• p_ini: Initial fraction of readily available water (-)

• p_mid: Fraction of readily available water at Lmid day of the cycle (-)

• p_end: Final Initial fraction of readily available water at Lend day of the cycle (-)

• Yini: Yield response factor (Ky, not used yet)

• Ydev: Yield response factor (Ky, not used yet)

• Ymid: Yield response factor (Ky, not used yet)

• Yend: Yield response factor (Ky, not used yet)

• Ytot: Yield response factor (Ky, not used yet)

• h: crop height (m) (not used)

• sowing_date: Sowing date in format "MM-DD"

The default crop parameters provided in the package come from a variety of sources.

Crop names starting with "KURN-" or "FAO-" are imported from the CRO files provided with the CropWat 8.0 installation. "KURN-" are crop parameters calibrated at "Kurnool, Andhra Pradesh, India".

Crop names starting with "SB2023-" are crop parameters coming from a calibration performed on outputs of the AqYield model for the Aveyron catchment (Soutif-Bellenger, 2023).

Reference

Soutif-Bellenger, Myriam, Guillaume Thirel, Olivier Therond, et Jean Villerd. 2023. As Simple as Possible but Not Simpler?: The Case of Irrigation Modeling at Catchment Scale in Southwestern France. Irrigation Science 41 (5): 713‑36.

Value

A tibble, see details for the column formats.

Examples

# Get available crops in the package
cp <- load_crop_params()
cp$crop

str(cp)

# Get parameters for sugar beet from FAO
get_crop_params("FAO-SUGARBET")

---

Load CropWat v8.0 crop parameter CRO file

Description

Load CropWat v8.0 crop parameter CRO file

Usage

load_CW8_CRO(file)

Arguments

file	Path of the CRO file

Value

Crop parameters formatted as

Examples

load_CW8_CRO(system.file("extdata/TOMATO.CRO", package = "CropWat"))

---

Plot time series of CropWat inputs and outputs

Description

Generic plotting function for objects of class CW_TS (including CW_input and CW_output). Dispatches to internal plotting functions based on the which argument.

Usage

## S3 method for class 'CW_TS'
plot(x, which = "daily", ...)

plot_daily(x, ...)

plot_yields(x, which_yields = NULL, ...)

Arguments

x	An object of class CW_TS, typically a CW_input object (from CW_create_input) or a CW_output object (from CW_run_simulation). For yield plots (which = "yields"), the object must have a relative_yield attribute.
which	Character vector that lists the kind of outputs to display. It can be "daily" and "yields". Default is "daily".
...	Additional arguments passed to the internal plotting functions. When which = "yields", which_yields can be passed to select which relative yield types to plot (see details).
which_yields	A character vector with the relative yield types to plot. It can contain "ini", "dev", "mid", "end", "cycle_stagewise", "cycle". If NULL (default), all available yield types are plotted.

Details

See CW_create_input and CW_run_simulation for examples.

Value

A list of ggplot2::ggplot() objects, one for each element in which.

Functions

• plot_daily(): Plot daily inputs and outputs as faceted line plots. Each variable in the input/output object is displayed in a separate panel with dates on the x-axis.

• plot_yields(): Plot estimated relative yields as faceted bar plots. Each yield type is displayed in a separate panel, with cycle IDs on the x-axis. Requires the input object to have a relative_yield attribute (typically produced by CW_run_simulation).

---

Climate example dataset

Description

A data.frame with 3 columns:

• Date: the date

• Prtot: precipitation (mm/day)

• ETP: Potential evaporation (mm/day)

Usage

ZH_3_clim

Format

An object of class spec_tbl_df (inherits from tbl_df, tbl, data.frame) with 2922 rows and 3 columns.

---