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 |