Potential evapotranspiration
"Maximum quantity of water capable of being evaporated from the soil and transpired from vegetation of a specified region in a given time interval under existing climatic conditions, expressed as depth of water." (United Nations Publications, 2013)
Sources
United Nations Publications. "Glossary of Shared Water Resources (English-Arabic): Technical, Socioeconomic and Legal Terminology." (2013). DOI:https://dx.doi.org/10.18356/70b462ce-en