UAV Image-Based Estimation of Surface Energy Balance Components in Sorghum under Different Irrigation Regimes

Precise knowledge of plot-scale surface energy partitioning is fundamental for agricultural water management, yet conventional ground or satellite techniques rarely resolve the heterogeneity for the plot scale areas. This study couples multispectral and thermal imagery acquired weekly–bi-weekly by a DJI Matrice-300 RTK/MicaSense-Altum platform with the physically based Two-Source Energy Balance (TSEB) model to quantify net radiation (Rn), soil heat flux (G), sensible heat flux (H) and latent heat flux (LE) in a randomized sorghum experiment comprising four irrigation levels (100, 70, 40 % ETc and rain-fed) in the Bafra Plain, Türkiye (May–October 2021). The model produced consistent seasonal trends: midday Rn peaked at 797 W m⁻², while G/Rn declined from ≈0.20 at emergence to