Tool Evapotranspiration (Table)
Estimation of daily potential evapotranspiration from weather data with different methods. Besides mean daily temperature it depends on the chosen method which additional data has to be provided. In order to estimate extraterrestrial net radiation some of the methods need to know the location's geographic latitude and the date's Julian day number.
References
- Allen, R.G., Pereira, L.S., Raes, D., Smith, M. (1998): Crop evapotranspiration - Guidelines for computing crop water requirements. FAO Irrigation and drainage paper 56. http://www.fao.org/docrep/X0490E/x0490e00.htm#Contents.
- Ambikadevi, K.M. (2004): Simulation of Evapotranspiration and Rainfall-runoff for the Stillwater River Watershed in Central Massachusetts. Environmental & Water Resources Engineering Masters Projects, University of Massachusetts, Amherst. http://scholarworks.umass.edu/cee_ewre/22/.
- DVWK (1996): Ermittlung der Verdunstung von Land- u. Wasserflaechen. Merkblaetter 238/1996.
- Hargreaves, G.H., Samani, Z.A. (1985): Reference crop evapotranspiration from ambient air temperatures. Paper presented in ASAE Regional Meeting, Grand Junction, Colorado. http://cagesun.nmsu.edu/~zsamani/papers/Hargreaves_Samani_85.pdf.
- Author: O.Conrad (c) 2011
- Menu: Climate and Weather|Evapotranspiration
Parameters
| Name | Type | Identifier | Description | Constraints |
Input | Data | Table, input | TABLE | - | - |
Output | Evapotranspiration (*) | Table, output, optional | RESULT | - | - |
Options | Mean Temperature | Table field | T | [Celsius] | - |
Minimum Temperature | Table field | T_MIN | [Celsius] | - |
Maximum Temperature | Table field | T_MAX | [Celsius] | - |
Relative Humidity | Table field | RH | [Percent] | - |
Solar Radiation | Table field | SR | daily sum of global radiation [J/cm^2] | - |
Wind Speed | Table field | WS | daily mean of wind speed at 2m above ground [m/s] | - |
Air Pressure | Table field | P | [kPa] | - |
Date | Table field | DATE | - | - |
Evapotranspiration (*) | Table field | ET | - | - |
Latitude | Floating point | LAT | - | Minimum: -90.000000 Maximum: 90.000000 Default: 53.000000 |
Method | Choice | METHOD | - | Available Choices: [0] Turc [1] Hargreave [2] Penman (simplified) [3] Penman-Monteith Default: 0 |
(*) optional |
Command-line
Usage: saga_cmd climate_tools 6 [-TABLE <str>] [-RESULT <str>] [-T <str>] [-T_MIN <str>] [-T_MAX <str>] [-RH <str>] [-SR <str>] [-WS <str>] [-P <str>] [-DATE <str>] [-ET <str>] [-LAT <double>] [-METHOD <str>]
-TABLE:<str> Data
Table, input
-RESULT:<str> Evapotranspiration
Table, output, optional
-T:<str> Mean Temperature
Table field
-T_MIN:<str> Minimum Temperature
Table field
-T_MAX:<str> Maximum Temperature
Table field
-RH:<str> Relative Humidity
Table field
-SR:<str> Solar Radiation
Table field
-WS:<str> Wind Speed
Table field
-P:<str> Air Pressure
Table field
-DATE:<str> Date
Table field
-ET:<str> Evapotranspiration
Table field
-LAT:<double> Latitude
Floating point
Minimum: -90.000000
Maximum: 90.000000
Default: 53.000000
-METHOD:<str> Method
Choice
Available Choices:
[0] Turc
[1] Hargreave
[2] Penman (simplified)
[3] Penman-Monteith
Default: 0