Performance of the SSEBop model in the estimation of the actual evapotranspiration of soybean and bean crops

Abstract

The objective of this work was to evaluate the performance of the operational simplified surface energy balance (SSEBop) model in the estimation of the actual evapotranspiration (ETa) of soybean and bean crops irrigated by a central pivot. The model estimates were obtained from digital images of the Landsat 7 and Landsat 8 satellites, and were compared with the ETa obtained by the Bowen ratio method. The model was evaluated by the refined agreement index (dr), root mean square error (RMSE), and mean bias error (MBE). The model's performance in the estimation of the ETa was classified by the performance index (Pi). The relationship between the estimates of the model and the Bowen ratio method showed correlation (r=0.94) and agreement (dr=0.82), with a mean square error of 0.62 mm per day and a mean bias error of 0.04 mm per day. The estimate perfomance of the SSEBop model in comparison with the Bowen ratio method, was classified as optimal (Pi=0.77), proving the SSEBop usability and precision to estimate ETa for irrigated crops, such as soybean and bean.