Utility of single-source surface energy balance models in estimation of daily actual evapotranspiration in arid regions
Nishchay Kumar, Mohamed A. Hamouda
Abstract
Single-source surface energy balance (SS-SEB) models estimate daily actual evapotranspiration (ETa eb) in arid and semi-arid regions. A meta-analysis explored the impact of model types, upscaling methods, satellite data selection, topography, and validation methods on ETa eb accuracy. SEBAL outperformed other SS-SEB models, especially in arid areas. Clear-sky models were more precise than continuous ones. For SEBAL, the Constant Reference Evaporative Fraction (ETrF) method was best for upscaling, while Constant Evaporative Fraction (EF) was optimal for METRIC, SEBS, and S-SEBI. Multi-source remote sensing data enhanced SS-SEB model performance compared to single-source data, particularly with higher spatial resolution. Study area size didn’t affect accuracy, but SEBAL struggled in higher altitudes and complex terrains. Lysimeter or FAO-56 validation yielded the best results. Recommendations include developing continuous SS-SEB models using appropriate methods and considering SSEB/SSEBop as alternatives to SEBAL and METRIC in data-scarce regions.