vp_deficit: Vapour pressure deficit

In WDNR-Water-Use/CSLSevap: Evapo(transpi)ration Calculations

Description

Calculates the vapour pressure deficit for a given time period (daily timestep or larger) using the mean daily minimum temperature, mean daily maximum temperature, mean daily minimum relative humidity, and mean daily maxiumum humidity during that time period. See p.39 and p.74 in Allen et al. (1998).

Usage

vp_deficit(atmp, RH)

Arguments

atmp	air temperature (degrees C). When dt is "daily" or larger, argument should be a list with elements "min" and "max" for daily min and max temperatures. When dt is "hourly", argument should be a vector with hourly recorded temperatures.
RH	relative humidity (percent). When dt is "daily" or larger, argument should be a list with elements "min" and "max" for daily min and max relative humidities. When dt is "hourly", argument should be a vector with hourly recorded relative humidities.

Value

vpd	vapour pressure deficit (kPa) for the given time period

References

Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop evapotranspiration: Guidelines for computing crop water requirements. Rome: FAO. Retrieved from http://www.fao.org/docrep/X0490E/x0490e00.htm.

WDNR-Water-Use/CSLSevap documentation built on April 9, 2021, 1:35 a.m.