Actual Evapotranspiration for Sugarcane Based on Bowen Ratio-Energy Balance and Soil Water Balance Models with Optimized Crop Coefficients

• Published in: Water resources management Vol. 36; no. 12; pp. 4557 - 4574
• Main Authors: da Costa Faria Martins, Suelen, dos Santos, Marcos Alex, Lyra, Gustavo Bastos, de Souza, José Leonaldo, Lyra, Guilherme Bastos, Teodoro, Iêdo, Ferreira, Fábio Freitas, Júnior, Ricardo Araújo Ferreira, dos Santos Almeida, Alexsandro Claudio, de Souza, Renan Cantalice
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2022; Springer Nature B.V
• Subjects: Atmospheric Sciences; Bowen ratio; Civil Engineering; Coefficients; Crops; Earth and Environmental Science; Earth Sciences; Energy balance; Environment; Evaluation; Evapotranspiration; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Hydrology/Water Resources; Inverse problems; Mathematical models; Methods; Moisture content; Objective function; Soil; Soil water; Sugarcane; Water balance; Water deficit; Water use; Water use efficiency; Thornthwaite and Mather; Dual Kc; Inverse modeling
• ISSN: 0920-4741; 1573-1650
• DOI: 10.1007/s11269-022-03263-5

Evapotranspiration is an important parameter to evaluate soil water deficit and water use efficiency, especially in locations with irregularly distributed precipitation. The aim of this study was to assess the daily actual evapotranspiration (ET a ) estimated by the Thornthwaite and Mather soil water balance adapted for crops (ThM) and by the dual Kc method with the crop coefficients optimized from inverse modeling and by the adjustment suggested in the FAO-56 bulletin. The models were optimized and evaluated with actual evapotranspiration determined by the Bowen ratio – energy balance method (ET β ) for sugarcane at full canopy closure grown in Alagoas state, northeastern Brazil. The objective function of the inverse problem was defined in terms of ET β and ET a estimated by the ThM or dual Kc method by optimizing the single crop coefficient (K c ) and the basal crop coefficient K cb , respectively. Optimized K c (1.05) and K cb (1.03) were lower than those adjusted by the K c FAO56 method (K c  = 1.25 or K cb  = 1.20), with optimized K c slightly higher than the K c obtained experimentally (1.01 ± 0.08). ET a estimated by the ThM and dual Kc method with optimized crop coefficients had similar high precision (r 2  > 0.79) and accuracy (d m  > 0.93 and RMSE < 0.30 mm d −1 ). However, using the coefficients adjusted from the FAO56 method overestimated ET a in both models.