Simulation of temporal variation for reference evapotranspiration under arid climate

2016 ◽  
Vol 9 (5) ◽  
Author(s):  
Amr Mossad ◽  
A. A. Alazba
2011 ◽  
Vol 26 (4) ◽  
pp. 500-512 ◽  
Author(s):  
Hossein Tabari ◽  
Ali Aeini ◽  
P. Hosseinzadeh Talaee ◽  
B. Shifteh Some'e

Irriga ◽  
2017 ◽  
Vol 1 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Roberta Daniela Silva Santos ◽  
Marcello Henryque Costa de Souza ◽  
Regiane De Carvalho Bispo ◽  
Kevim Muniz Ventura ◽  
Luis Henrique Bassoi

COMPARAÇÃO ENTRE MÉTODOS DE ESTIMATIVA DA EVAPOTRANSPIRAÇÃO DE REFERÊNCIA PARA O MUNICÍPIO DE PETROLINA, PE  ROBERTA DANIELA DA SILVA SANTOS1; MARCELLO HENRYQUE COSTA DE SOUZA1; REGIANE DE CARVALHO BISPO1; KEVIM MUNIZ VENTURA1 E LUÍS HENRIQUE BASSOI2 1Programa de Pós-Graduação em Irrigação e Drenagem, Universidade Estadual Paulista “Júlio de Mesquita Filho”- UNESP/FCA, Rua Dr. José Barbosa de Barros, 1780, Botucatu, SP, [email protected], [email protected], [email protected], [email protected] Embrapa Instrumentação, São Carlos, SP, [email protected]  1 RESUMO O conhecimento da evapotranspiração é vital na determinação das necessidades hídricas de uma cultura. Diante disso, o objetivo deste trabalho foi comparar o desempenho de sete métodos de estimativa da evapotranspiração de referência em relação ao método de Penman-Monteith, adotado como padrão, para o município de Petrolina, PE. Foram utilizados dados climáticos diários de 2004 a 2015, para estimar da ET0, obtidos na estação meteorológica automática do Campo Experimental de Bebedouro da Embrapa Semiárido, Petrolina, PE. Os indicadores estatísticos utilizados na avaliação foram: coeficiente de determinação (r²); coeficiente de correlação (r); índice de concordância (d) e índice de desempenho (c). Os valores do r² mostraram que o método de estimativa que melhor se ajustou ao método de Penman-Monteith foi o de Ivanov (0,73); seguido pelos métodos de Jensen-Haise (0,64); Makkink e Priestley-Taylor (0,63); Villa Nova (0,62); Hargreaves e Samani (0,53) e Hamon (0,45). No entanto, com relação ao do índice “c”, Hamon foi classificado com “péssimo”; Makkink como “mau”; Hargreaves e Samani e Villa Nova como “sofrível”; Ivanov e Priestley-Taylor como “mediano”; e Jensen-Haise como “bom”. Esse último método foi considerado como o de melhor classificação de desempenho. Palavras-chave: Penman-Monteith, correlação, semiárido.  SANTOS, R. D. S.; SOUZA, M. H. C.; BISPO, R. de C.; VENTURA, K. M.; BASSOI, L. H.METHOD-COMPARISON STUDY TO ESTIMATE THE REFERENCE EVAPOTRANSPIRATION IN PETROLINA, PE  2 ABSTRACT The knowledge on evapotranspiration is vital in determining the water requirements of a crop. Therefore, this paper aims to compare the performance of seven of estimation methods for the reference evapotranspiration in relation to the Penman-Monteith method, adopted as standard, for the municipality of Petrolina, state of Pernambuco, Brazil. We used daily climatic data from 2004 to 2015 to estimate the ET0 coefficient, obtained in the automatic weather station of the Test Field in Bebedouro, Embrapa in the Semi-arid climate. The statistical indicators used in the evaluation were: coefficient of determination (r²), correlation coefficient (r), agreement index (d) and performance index (c). The r2 values showed that the estimation method that best fitted to the Penman-Monteith method was Ivanov's (0.73), followed by Jensen-Haise (0.64), Makkink and Priestley-Taylor (0.63), Villa Nova (0.62), Hargreaves and Samani (0.53) and Hamon (0.45) methods. However, in relation to the index "c", Hamon was classified as "very poor"; Makkink as "poor"; Hargreaves and Samani and Villa Nova as "tolerable"; Ivanov and Priestley-Taylor as "medium"; and Jensen-Haise as "good". The last one was considered as the best performance rating method. Keywords: Penman-Monteith, correlation, semi-arid climate.


2020 ◽  
Vol 238 ◽  
pp. 104868 ◽  
Author(s):  
Linshan Yang ◽  
Qi Feng ◽  
Jan F. Adamowski ◽  
Zhenliang Yin ◽  
Xiaohu Wen ◽  
...  

2021 ◽  
Vol 13 (1) ◽  
pp. 95-115
Author(s):  
Augusto Omar Villa-Camacho ◽  
◽  
Ronald Ernesto Ontiveros-Capurata ◽  
Osías Ruíz-Álvarez ◽  
Alberto González-Sánchez ◽  
...  

<strong>Introduction:</strong> Evapotranspiration is key in the management of arid agricultural areas. In Chihuahua, the volume of irrigation water is based on reference evapotranspiration (ET<sub>o</sub>) calculated with empirical methods and extrapolated to the cropped area, which is inaccurate. The alternative is to calculate ET<sub>o</sub> variation by spatial interpolation.</br> <strong>Objective:</strong> To analyze the spatio-temporal variation of ET<sub>o</sub> using empirical methods and spatial interpolation in Chihuahua, Mexico.</br> <strong>Methodology:</strong> Records from 33 meteorological stations from 1960-2013 and seven ET<sub>o</sub> estimation methods were used. The results were compared with the Penman-Monteith method, modified by FAO (PMMF), ANOVA analysis (P ≤ 0.05), and homogeneous ET<sub>o</sub> surfaces built from the point values by spatial interpolation.</br> <strong>Results:</strong> The Hargreaves method (R<sup>2</sup> = 0.91, RMSE = 1.16 and ME = -0.69 mm-day<sup>-1</sup>) had a smaller bias with respect to PMMF. ET<sub>o</sub> values ranged from 2.5 to 7.1 mm-day<sup>-1</sup> in a west-east direction, with maximum values at low elevations and minimum values at high elevations, which showed the influence of the Sierra Madre Occidental on ET<sub>o</sub>. This characteristic was most noticeable in the warm months (June to September).</br> <strong>Limitations of the study:</strong> The use of estimated data needs field validation.</br> <strong>Originality:</strong> The ET<sub>o</sub> estimation with seven empirical methods and one spatial interpolation method to extrapolate values to areas with scarce meteorological data.</br> <strong>Conclusions:</strong> The Hargreaves method allows estimating the spatio-temporal variation of ET<sub>o</sub> in large extensions and areas with limited meteorological information.</br>


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