Estimating evapotranspiration is an essential step towards the calculation of crops irrigation needs. One of the most widely used methods for this estimation is Surface Energy Balance Algorithm (SEBAL), a method based on remote sensing imagery. In the current study, fusion images of Landsat 8 and MODIS satellites using Gram-Schmidt algorithm were employed to calculate actual evapotranspiration of the Amir Kabir sugarcane argo-industry company, Khuzestan, Iran. Furthermore, the amount of sugarcane evapotranspiration was estimated using Landsat 8 images and SEBAL algorithm, and finally, the results were compared with lysimeteric data. The comparison of evapotranspiration from Landsat 8 and lysimeteric data showed a correlation higher than 0.96, as well as a comparison of evapotranspiration from the Landsat-MODIS fusion images having a suitable correlation equal to 0.88 with the lysimeteric data. In this research, the amount of dry matter produced in farming year 2016–2017 was calculated by using the Monteith model and satellite images. The average dry matter produced (biomass) of sugarcane in this period estimated using Landsat 8 images was 52.51ton/ha and 42.45ton/ha with fusion images. The average water use efficiency from the dry matter ratio produced by the actual evapotranspiration estimated from satellite data for Landsat 8 images and Landsat-MODIS fusion images was 5.98 and 5.95 kg/m³, respectively. Also, the relationship between age and sugarcane varieties with yield and evapotranspiration rates calculated by the Monteith and SEBAL model indicated that the effect of the age of the sugarcane and varieties on its evapotranspiration rate is negligible. Finally, the relationship between the estimated evapotranspiration by Landsat 8 images and NDVI revealed that the extraction of NDVI values from images could be achieved with the proper accuracy of evapotranspiration.

估算蒸散量是计算农作物灌溉需求的必不可少的步骤。用于此估计的最广泛使用的方法之一是表面能量平衡算法（SEBAL），这是一种基于遥感影像的方法。在当前的研究中，采用了使用Gram-Schmidt算法的Landsat 8和MODIS卫星融合图像来计算伊朗Khuzestan的Amir Kabir甘蔗果品工业公司的实际蒸散量。此外，使用Landsat 8图像和SEBAL算法估算了甘蔗的蒸散量，最后将结果与溶渗仪数据进行了比较。Landsat 8的蒸散量与测地数据的比较表明，相关系数高于0.96，以及从Landsat-MODIS融合图像得到的蒸散量的比较，该图像与测渗数据的相关系数等于0.88。在这项研究中，通过使用Monteith模型和卫星图像计算了2016-2017农业年度的干物质产量。使用Landsat 8影像估算的这段时期甘蔗的平均干物质产量（生物量）为52.51吨/公顷，融合影像为42.45吨/公顷。根据Landsat 8影像和Landsat-MODIS融合影像的卫星数据估算的实际蒸散产生的干物质比产生的平均水分利用效率分别为5.98和5.95 kg / m 使用Landsat 8影像估算的这段时期甘蔗的平均干物质产量（生物量）为52.51吨/公顷，融合影像为42.45吨/公顷。根据Landsat 8影像和Landsat-MODIS融合影像的卫星数据估算的实际蒸散产生的干物质比产生的平均水分利用效率分别为5.98和5.95 kg / m 使用Landsat 8影像估算的这段时期甘蔗的平均干物质产量（生物量）为52.51吨/公顷，融合影像为42.45吨/公顷。根据Landsat 8影像和Landsat-MODIS融合影像的卫星数据估算的实际蒸散产生的干物质比产生的平均水分利用效率分别为5.98和5.95 kg / m³，分别。此外，通过蒙特斯和SEBAL模型计算的年龄和甘蔗品种与产量和蒸散速率之间的关系表明，甘蔗和品种的年龄对其蒸散速率的影响可以忽略不计。最后，Landsat 8图像估计的蒸散量与NDVI之间的关系表明，可以以适当的蒸散精度实现从图像中提取NDVI值。