PyETo

PyETo is a Python package for calculating reference crop evapotranspiration (ETo), sometimes referred to as potential evapotranspiration (PET). The library provides numerous functions for estimating missing meteorological data.

Three methods for estimating ETo/PET are implemented:

  • FAO-56 Penman-Monteith (Allen et al, 1998)
  • Hargreaves (Hargreaves and Samani, 1985)
  • Thornthwaite (Thornthwaite, 1948)

What does it look like? Here is a simple example that estimates monthly potential evapotranspiration for Aberdeen, Scotland (latitude 57.1526 degrees N), using the Thornthwaite method:

>>> import pyeto
>>> latitude = pyeto.deg2rad(57.1526)   # Convert latitude to radians
>>> mean_monthly_temperature = [
 >>>     3.1, 3.5, 5.0, 6.7, 9.3, 12.1, 14.3, 14.1, 11.8, 8.9, 5.5, 3.8]
>>> monthly_mean_daylight = pyeto.monthly_mean_daylight_hours(latitude)
>>> pyeto.thornthwaite(mean_monthly_temperature, monthly_mean_daylight)
 [11.04590543317501,
  14.225860424373405,
  27.802870598091953,
  43.178869424774305,
  70.47694909766452,
  93.99420906995957,
  109.69881616481408,
  95.24491684988213,
  64.9945211942068,
  41.06371810827504,
  19.562094545836995,
  12.090183352107148]

Installation

There is currently no way to install this package so you will have to include the source in your project in order to use it.

Documentation contents

This part of the documentation guides you through the various evapotranspiration methods.

API Reference

If you are looking for information on a specific function, this part of the documentation is for you.