(2025 AGU Conference) Best Practices on the Use of sUAS for the Estimation of Evapotranspiration and ET Partitioning Using the Two-Source Energy Balance Model: Examples from Vineyards, Almonds, Urban Green Areas, and Other Crops in the Western US and World’s Arid Regions

Small Unmanned Aerial Systems (sUAS) have emerged as a transformative technology for high-resolution estimation and partitioning of evapotranspiration (ET) in heterogeneous landscapes characterized by tall, clumped canopies and variable interrow conditions. This study synthesizes methodological advances and best practices derived from over a decade of sUAS-based research across vineyards, almond orchards, turfgrass systems, urban green spaces, and other crops in semi-arid regions of the Western United States (California and Utah), as well as collaborative initiatives in Chile, Peru, and Turkey.

The analytical framework is grounded in the Two-Source Energy Balance (TSEB) model, integrating drone-acquired thermal, multispectral, and digital surface model (DSM) imagery to quantify total ET and partition fluxes into soil evaporation and plant transpiration.

The synthesis draws upon insights from multiple programs, including:

AggieAir sUAS Research Group at Utah State University,
USDA-led GRAPEX (Grape Remote Sensing Atmospheric Profile & Evapotranspiration Experiment),
USDA-led T-REX (Tree-Crop Remote Sensing of Evapotranspiration Experiment),
USU-led TURF-EX (Turfgrass Evapotranspiration Exp), and
international work: UTALCA-CITRA (Chile, nut crops), Duzce University (Turkey, peppers) and TyC in Peru (ECOSMART RICE).