Improvement of reference crop evapotranspiration estimates using limited data for the Brazilian Cerrado

Abstract

One of the most affordable methods of estimating ET is first to estimate reference crop evapotranspiration (ETo) and later associate it to crop and soil coefficients. The FAO Kc-ETo approach can be used only when ETo is computed with the FAO Penman-Monteith equation.However, low data availability may restict the equations used to estimate ETo. In this study, we assess and calibrate common methods used to estimate ETo under such conditions of limited data availability. Based on the annual calibration, the Makkink (NSE = 0.85) outperformed the Priestley-Taylor (NSE = 0.73), Hargreaves-Samani (NSE = 0.56), and Penman-Monteith temperature approach (NSE = 0.58). The seasonal calibration of parameters showed no significant improvement to the methods assessed (ΔNSE ≤ 0.01), except for the Priestley-Taylor (ΔNSE = 0.06). The performance of temperature-based equations was particularly limited due to the performance of the equation adopted to estimate global solar radiation. Thus, improving the representation of global solar radiation for limited data availability can also play a key role in improving ETo prediction.

Water rights in sugarcane irrigation: influence of irrigation criteria and probability levels adopted for ETo and rainfall

“…Even in areas with a humid climate, irregular distribution of rainfall in some periods can limit plant growth. Sugarcane crops and mills worldwide are located in regions with a broad climate variability; thus, dealing with these factors is essential to ensure a profitable and sustainable production (Gilbert et al, 2006;Souza et al, 2020;Fattori Junior et al, 2022;Amorim et al, 2022;Althoff and Rodrigues, 2023).…”

Estimation of Reference Evapotranspiration in a Semi-Arid Region of Mexico

“…Crop evapotranspiration (ET C ) is a crucial aspect of the water balance in agricultural areas. To estimate it, the most accessible method is to estimate reference evapotranspiration (ET 0 ) and then pair it with crop and soil coefficients [8]. Reference evapotranspiration (ET 0 ) is the evapotranspiration rate of a hypothetical reference crop (grass or alfalfa) with a height of 0.12 m, a fixed surface resistance of 70 s m −1 , and an albedo of 0.23, homogeneous, well-watered, free from diseases and pests, growing vigorously, and providing complete that higher spatial resolution does not necessarily imply higher precision [50].…”

Estimation of Reference Evapotranspiration in a Semi-Arid Region of Mexico

“…Crop evapotranspiration (ET C ) is a crucial aspect of the water balance in agricultural areas. To estimate it, the most accessible method is to estimate reference evapotranspiration (ET 0 ) and then pair it with crop and soil coefficients [ 8 ]. Reference evapotranspiration (ET 0 ) is the evapotranspiration rate of a hypothetical reference crop (grass or alfalfa) with a height of 0.12 m, a fixed surface resistance of 70 s m −1 , and an albedo of 0.23, homogeneous, well-watered, free from diseases and pests, growing vigorously, and providing complete shade to the soil [ 9 , 10 , 11 ].…”