Tool ETpot (after Hargreaves, Table)
Estimation of daily potential evapotranspiration from daily average, minimum and maximum temperatures using Hargreave's empirical equation. In order to estimate extraterrestrial net radiation geographic latitude of observation and Julian day have to be supplied too.
References
- 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/.
- Hargraeves, 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.
- 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.
- Author: O.Conrad (c) 2011
- Menu: Climate|Evapotranspiration
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Data | Table (input) | TABLE | - | - |
| Options | Julian Day | Table field | JD | - | - |
| Mean Temperature | Table field | T | - | - |
| Minimum Temperature | Table field | T_MIN | - | - |
| Maximum Temperature | Table field | T_MAX | - | - |
| Latitude | Floating point | LAT | - | Minimum: -90.000000
Maximum: 90.000000
Default: 53.000000 |
Command-line
Usage: saga_cmd climate_tools 6 [-TABLE <str>] [-JD <str>] [-T <str>] [-T_MIN <str>] [-T_MAX <str>] [-LAT <double>]
-TABLE:<str> Data
Table (input)
-JD:<str> Julian Day
Table field
-T:<str> Mean Temperature
Table field
-T_MIN:<str> Minimum Temperature
Table field
-T_MAX:<str> Maximum Temperature
Table field
-LAT:<double> Latitude
Floating point
Minimum: -90.000000
Maximum: 90.000000
Default: 53.000000