hydromt.workflows.forcing.pm_fao56#

hydromt.workflows.forcing.pm_fao56(temp: DataArray, temp_max: DataArray, temp_min: DataArray, press: DataArray, kin: DataArray, wind: DataArray, temp_dew: DataArray, dem: DataArray, var: str = 'temp_dew') DataArray[source]#

Estimate daily reference evapotranspiration (ETo).

Based on a hypothetical short grass reference surface using the FAO-56 Penman-Monteith equation. Actual vapor pressure is derived either from relative humidity or dewpoint temperature (depending on var_for_avp_name). Based on equation 6 in Allen et al (1998) and using the functions provided by the pyet package ()

Parameters:
  • temp (xarray.DataArray) – DataArray with daily temperature [°C]

  • temp_max (xarray.DataArray) – DataArray with maximum daily temperature [°C]

  • temp_min (xarray.DataArray) – DataArray with minimum daily temperature [°C]

  • press (xarray.DataArray) – DataArray with pressure [hPa]

  • kin (xarray.DataArray) – DataArray with global radiation [W m-2]

  • wind (xarray.DataArray) – DataArray with wind speed at 2m above the surface [m s-1]

  • temp_dew (xarray.DataArray) – DataArray with either temp_dew (dewpoint temperature at 2m above surface [°C]) or rh (relative humidity [%]) to estimate actual vapor pressure

  • dem (xarray.DataArray) – DataArray with elevation at model resolution [m]

  • var (str, optional) – String with variable name used to estimate actual vapor pressure (chose from [“temp_dew”, “rh”])

Returns:

DataArray with the estimated daily reference evapotranspiration pet [mm d-1]

Return type:

xarray.DataArray

Raises:

ModuleNotFoundError – In case the pyet module is not installed