FAO Penman-Monteith equation determines the evapotranspiration from the hypothetical grass reference surface. (FAO 56)
Uses daily max/min temperature, actual vapour pressure, net radiation and wind speed. Checks for valid actual vapour pressure values.
For documentation of the formulas please check the orginal reference (FAO 56)
Content Type | Name | Description | Data Type | Unit | Min Value | Max Value | Default Value |
---|---|---|---|---|---|---|---|
constant | cAltitude | elevation above sea level | DOUBLE | m | - | - | 0.0 |
constant | cLatitude | latitude | DOUBLE | ° | -90.0 | 90.0 | 0.0 |
input | iActualVapourPressure | actual vapour pressure | DOUBLEARRAY | kPa | - | - | null null null null null null null null null null null null null null null null null null null null null null null null |
input | iNetRadiation | net radiation | DOUBLEARRAY | megajoule_per_square_metre_hour | - | - | null null null null null null null null null null null null null null null null null null null null null null null null |
input | iT | hourly daily temperature | DOUBLEARRAY | °C | - | - | null null null null null null null null null null null null null null null null null null null null null null null null |
input | iWindspeed | wind speed at 2m height | DOUBLEARRAY | metre_per_second | - | - | null null null null null null null null null null null null null null null null null null null null null null null null |
out | ReferenceCropEvapotranspiration | hourly reference evapotranspiration (ET0) | DOUBLEARRAY | mm/h | - | - | null null null null null null null null null null null null null null null null null null null null null null null null |
out | ReferenceCropEvapotranspirationDaily | daily reference evapotranspiration (ET0) | DOUBLE | mm/d | - | - | 0.0 |