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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Publications at this Location » Publication #401711

Research Project: Improving Water Management for Arid Irrigated Agroecosystems

Location: Water Management and Conservation Research

Title: Version 1.1.0-pyfao56: FAO-56 evapotranspiration in Python

item Brekel, Joshua
item Thorp, Kelly
item DeJonge, Kendall
item Trout, Thomas

Submitted to: SoftwareX
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2023
Publication Date: 2/13/2023
Citation: Brekel, J.J., Thorp, K.R., DeJonge, K.C., Trout, T.J. 2023. Version 1.1.0-pyfao56: FAO-56 evapotranspiration in Python. SoftwareX. 22. Article 101336.

Interpretive Summary: The seminal publication of FAO-56 described standardized methods to estimate crop water use or evapotranspiration (ET), which is a critical aspect of irrigation management, water rights in many Western states, and large-scale studies of hydrology. In the first release of the "pyfao56" software, the FAO-56 methodology was programmed using the modern open-source Python programming environment. The current pyfao56 release (version 1.1.0) adds considerable functionality to the original software, including expansion of reference ET algorithms, consideration of variable soil characteristics with depth, and enhanced soil water depletion calculations. The pyfao56 software serves as a useful tool or framework for users of ET-based irrigation scheduling, which includes agronomists, crop consultants, irrigators, and agricultural water researchers.

Technical Abstract: The pyfao56 software package is a Python-based implementation of the standardized evapotranspiration (ET) methodologies described in Irrigation and Drainage paper No. 56 of the Food and Agriculture Organization of the United Nations, commonly known as FAO-56. This update improved pyfao56 by (1) fixing a major bug related to testing for availability of weather data, (2) expanding options for reference ET calculations including hourly estimates, (3) adding functionality to specify variable soil characteristics with profile depth, (4) including optional water balance enhancements that consider soil water depletion for both the dynamic and maximum root zones, and (5) enabling the use of either constant or variable depletion fraction (p). The updates increase software versatility and expand options for use, while also maintaining the core functionality of the original software design.