pyet is an open source python package for calculating reference and potential evaporation (PE). Currently eighteen methods for calculating daily PE are implemented:
| Classification | Common method name | Data needed | pyet Method | Reference |
|---|---|---|---|---|
| Combination | Penman | RH, T, U, D | penman |
Penman (1948) |
| Penman-Monteith | RH, T, U, D | pm |
Monteith (1965) | |
| Penman-Monteith ASCE | RH, T, U, D | pm |
ASCE (2005) | |
| FAO-56 | RH, T, U, D | pm_fao56 |
Allen et al. (1998) | |
| Priestley-Taylor | T, D | priestley_taylor |
Priestley and Taylor (1972) | |
| Kimberly-Penman | RH, T, U, D | kimberly_penman |
Wright (1982) | |
| Thom-Oliver | RH, T, U, D | thom_oliver |
Thom and Oliver (1977) | |
| Temperature | Blaney–Criddle | T, D | blaney_criddle |
Blaney and Criddle (1952) |
| Hamon | T | hamon |
Hamon (1963) | |
| Romanenko | RH, T | romanenko |
Xu and Singh (2001) | |
| Linacre | T | linacre |
Linacre (1977) | |
| Radiation | Turc | T, D | turc |
Xu and Singh (2001) |
| Jensen–Haise | T, D | jensen_haise |
Jensen (1963) | |
| McGuinness–Bordne | T, D | mcguinness_bordne |
McGuinness (1972) | |
| Hargreaves | T | hargreaves |
Hargreaves and Samani (1982) | |
| Doorenbos–Pruitt (FAO-24) | RH, T, U, D | fao_24 |
Jensen et al. (1990) | |
| Abtew | T, D | abtew |
Abtew (1996) | |
| Makkink | T, D | makkink |
Makkink (1957) | |
| Oudin | T | oudin |
Oudin (2005) |
T, Temperature; U, Wind Speed; D, Radiation; RH, Relative Humidity. Adapted from [@oudin2005potential].
Note: The Penman-Monteith ASCE method can be applied on the hourly and daily time scales.
Examples of using pyet can be found in the example folder. This folder also contains a number of Jupyter Notebooks that thoroughly explain the use of the software. Documentation is hosted on ReadTheDocs.
After defining the input data, evaporation is estimated using only one line of python code:
>>> pyet.pm_fao56(tmean, wind, rn=rn, tmax=tmax, tmin=tmin, rh=rh, elevation=elevation)
pyet is in active development, and bug reports are welcome as GitHub Issues. General questions or discussions are possible through GitHub Discussions.
The pyet package is available from the Pypi package index and can be installed as follows:
>>> pip install pyet
To install in developer mode, use the following syntax:
>>> pip install -e .
If you use pyet for one of your projects, we ask that you cite the code as follows: Vremec, M., Collenteur, R., (XXXX). PyEt-open source python package for calculating reference and potential evaporation (Version X.X.X). Zenodo.