Evaluation of the Penman-Monteith (FAO 56 PM) Method for Calculating Reference Evapotranspiration Using Limited Data

(Figure Presented) Reference evapotranspiration (ETo) is often calculated using the Penman-Monteith (FAO 56 PM; Allen et al 1998) method, which requires data on temperature, relative humidity, wind speed, and solar radiation. But in high-mountain environments, such as the Andean páramo, meteorologic...

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Detalles Bibliográficos
Autores: Cordova Mora, Mário Andrés, Carrillo Rojas, Galo Jose, Celleri Alvear, Rolando Enrique, Crespo Sanchez, Patricio Javier
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Ecuador
Institución:Universidad de Cuenca
Repositorio:Repositorio Universidad de Cuenca
OAI Identifier:oai:dspace.ucuenca.edu.ec:123456789/28993
Acceso en línea:https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941630485&doi=10.1659%2fMRD-JOURNAL-D-14-0024.1&partnerID=40&md5=5c3f8c4aa87341fce44007384eafa370
http://dspace.ucuenca.edu.ec/handle/123456789/28993
Access Level:acceso abierto
Palabra clave:Andes
Ecuador
Limited Data
Meteorological Data
Mountainous Regions
Penman-Monteith
Reference Evapotranspiration
Tropical Mountains
Descripción
Sumario:(Figure Presented) Reference evapotranspiration (ETo) is often calculated using the Penman-Monteith (FAO 56 PM; Allen et al 1998) method, which requires data on temperature, relative humidity, wind speed, and solar radiation. But in high-mountain environments, such as the Andean páramo, meteorological monitoring is limited and high-quality data are scarce. Therefore, the FAO 56 PM equation can be applied only through the use of an alternative method suggested by the same authors that substitutes estimates for missing data. This study evaluated whether the FAO 56 PM method for estimating missing data can be effectively used for páramo landscapes in the high Andes of southern Ecuador. Our investigation was based on data from 2 automatic weather stations at elevations of 3780 m and 3979 m. We found that using estimated wind speed data has no major effect on calculated ETo but that if solar radiation data are estimated, ETo calculations may be erroneous by as much as 24%; if relative humidity data are estimated, the error may be as high as 14%; and if all data except temperature are estimated, errors higher than 30% may result. Our study demonstrates the importance of using high-quality meteorological data for calculating ETo in the wet páramo landscapes of southern Ecuador.