Analysis of reference evapotranspiration of Janaúba, mg

Idesia

Gonçalves Lopes, Érika Manuela¹  Mendes Reis, Matheus¹  Gonçalves Oliveira, Flávio¹ 

[1] Universidade Federal de Minas Gerais, Montes Claros, Brazil

关键词: Penman Monteith;    Hargreaves Samani;    frequency of occurrence;    water;    agrometeorology.;   

DOI  :  10.4067/S0718-34292016005000017

学科分类：农业科学（综合）

来源: Universidad de Tarapaca * Facultad de Agronomia

【 摘 要 】

Knowledge of the reference evapotranspiration (ETo) is essential for the irrigation management of agricultural crops worldwide. The Penman Monteith demand different weather variables, which hinders its application in areas with few weather stations such as the north of Minas Gerais. This work, compare the method of Hargreaves Samani with Penman Monteith and determine the frequency of occurrence of the reference evapotranspiration in the city of Janaúba, MG. To assess the fit of Hargreaves Samani equation with Penman Monteith used the coefficient of determination (r2), the coefficient of correlation (r), the standard error of estimate (SEE), the index agreement (d) and the index performance (c). Kimball's method was used for determining the frequency of occurrence. The results indicate that the Hargreaves Samani method overestimates the values of Penman Monteith at 8%, but in the monthly analysis, it is observed that between the months April to August Penman values were superior to Hargreaves. All statistical criteria used showed Hargreaves Samani fitted equation with a better assessment when compared with the Penman Monteith. The higher frequency of occurrence was between 4.5 and 4.7 mm day-1 (6.62%) and the equation that indicates the probability of being equaled or exceeded evaporation showed an r2 equal to 0.9676.

【 授权许可】

CC BY-NC