Water Productivity (WP) — water_productivity • wefnexus

Computes physical or economic water productivity per unit of water used.

water_productivity(
  yield,
  water_applied,
  price = NULL,
  unit = "mm",
  verbose = TRUE
)

Arguments

yield: Numeric vector. Crop yield (kg/ha).
water_applied: Numeric vector. Total water applied (mm or m3/ha).
price: Numeric. Market price per kg of produce (currency/kg). If NULL (default), returns physical water productivity.
unit: Character. Unit of water input: "mm" (default) or "m3".
verbose: Logical. If TRUE, prints informational messages. Default TRUE.

Value

Numeric vector. Physical water productivity in kg/m3 when price is NULL, or economic water productivity in currency/m3 when price is specified.

Details

Physical water productivity: $$WP = \frac{Y}{W_{m3}}$$

Economic water productivity: $$WP_{econ} = \frac{Y \times P}{W_{m3}}$$

When unit = "mm", water is converted to m3/ha using 1 mm = 10 m3/ha.

References

Molden, D. et al. (2010). Improving agricultural water productivity: Between optimism and caution. Agricultural Water Management, 97(4), 528-535. doi:10.1016/j.agwat.2009.03.023

Examples

water_productivity(4500, 500, unit = "mm")
#> Physical WP computed (kg/m3).
#> [1] 0.9
water_productivity(4500, 500, price = 25, unit = "mm")
#> Economic WP computed (currency/m3).
#> [1] 22.5