Coefficients of the Angström-Prescott equation and its influence on evapotranspiration in Seropedica, Rio de Janeiro State, Brazil

Revista Brasileira de Engenharia Agrícola e Ambiental

Silva, Dione G. da¹  Rocha, Hermes S. da¹  Gomes, Daniela P.¹  Carvalho, Daniel F. de²  Souza, Adilson P. de³ 

[1] UFRRJ;UFMT, Sinop, Brasil

关键词: solar radiation;    sunshine;    weather station;    Penman-Monteith    INTRODUÇÃO A radiação solar é a fonte de energia primária para os fenômenos meteorológicos;    além de ser responsável por todos os processos físicos e bioquímicos que ocorrem no planeta;   

DOI  :  10.1590/S1415-43662011000800011

学科分类：农业科学（综合）

来源: Universidade Federal de Campina Grande * Centro de Ciencias e Tecnologia

【 摘 要 】

The reference evapotranspiration (ETo) is dependent on the amount of energy available in the environment, being solar radiation (SR) as an important variable in its estimation. This study was carried out in order to determine the coefficients "a" and "b" of the Angstron-Prescott equation for Seropédica, Rio de Janeiro State, Brazil, and to evaluate their effects on the SR and ETo estimation. Measures of global solar radiation and effective number of hours of sunshine were used from station Ecology Fund (83741 - INMET) for the period of 2000 to 2007. The coefficients were determined by linear regression analysis for the entire period and monthly and yearly periods. Using the calculated coefficients and those proposed by FAO (0.25 and 0.50) SR and ETo were estimated and evaluated their performance. The average monthly coefficients "a" ranged from 0.232 to 0.299 and "b" from 0.397 to 0.504. Annual mean coefficients "a" and "b" were 0.295 and 0.417, and for general period were 0.282 and 0.433, respectively. The best performance observed for the estimated SR and ETo was obtained when the monthly coefficients of the equation Angströn-Prescott were adopted.

【 授权许可】

CC BY-NC