Location: Hydrology and Remote Sensing Laboratory
Project Number: 8042-13610-030-025-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 15, 2017
End Date: Sep 14, 2022
Objective:
Improve remote sensing-based evpotranspiration modeling of water and energy exchanges in structured agricultural environments with particular emphasis on vineyards.
Approach:
Data collected from intensive field campaigns (Intensive Observation Periods; IOPs) over different vine varieties and climates as part of the multi-year Grape Remote sensing Atmospheric Profile and Evapotranspiration experiment (GRAPEX) in concert with airborne and satellite remote sensing imagery will be used as input to current remote sensing-based evpotranspiration/energy balance models over vineyards in California. Output of surface energy balance and ET from the vine canopy and inter-row will be compared to ground-truth measurements at different vine and inter-row cover crop physiological stages. The ground-truth measurements are an extensive set of observations which include surface energy balance, evapotranspiration (ET), root zone soil moisture and plant physiological, spectral and biophysical data. Refinements to the models for improving ET and energy partitioning between vine and inter-row systems based on ground truth measurements collected will be developed. The refined models will be applied to multiple vineyards and evaluated at expanded test sites. The finer resolution airborne imagery coupled to the improved thermal-based two-source energy balance model for distinguishing vine and soil/cover crop contributions to total water use and root zone water availability will also be used to evaluate and refine thermal sharpening techniques that are applied to coarser resolution satellite sensors for estimating separate vine and cover crop contributions to total ET. An ET product will be made available to the Cooperator for integrating into operational irrigation scheduling and water management decision making tools for vineyard growers and managers. Similar efforts can be made in existing experimental orchards already established and maintained by the cooperator to start to expand this effort beyond vineyards and into other economically important woody perennial crops in California.
