The GRAPEX project: Understanding vineyard evapotranspiration in order to develop remote sensing tools to detect stress and reduce water use Dr. Williams Kustas USDA-Agricultural Research Service, USA

The Grape Remote sensing Atmospheric Profile and Evapotranspiration eXperiment (GRAPEX) has a goal of developing remote sensing-based evapotranspiration (ET) toolkit using earth observations for monitoring vineyard water use and stress from with-in vineyard block to regional scales in the California Central Valley. To enhance sustainability of vineyards in this region, which experiences frequent drought, this information is key to reducing water use while maintaining yield and quality. Through this research project, measurements of vine physiology, soil moisture, water, carbon and energy exchange processes and relationships between remote sensing retrieval algorithms of vine biomass, leaf area, land surface temperature and vineyard fluxes have advanced the understanding of modeling vine water use and stress. This presentation will provide a summary of key GRAPEX findings from in situ and remote sensing observations collected from the leaf and canopy level to the field and landscape scales in estimating vine water use and stress. Future research directions will also be discussed.