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Oral

Irrigation & Drainage

Crop Model and Remote Sensing in Irrigation and Hydrology

High-resolution evapotranspiration mapping of arid pecan orchard using aerial remote sensing data

Wednesday, May 24, 2023
4:45 PM – 5:00 PM PDT
Room: El Viento IV
Uncrewed aerial vehicles (UAV) and sensor technology have the potential to improve field-level research by providing high spatiotemporal resolution with data acquisition flexibility. Pecan orchards in the southwest Texas and New Mexico border are exposed to arid climates with limited water supplies. Understanding and controlling evapotranspiration (ET), particularly non-consumptive ET losses, from flood-irrigated fields are critical for farm sustainability. The water balances and ET in these orchards are linked to several factors, including irrigation, soil and water salinity, and nutrient availability, all of which are essential cogs for a sustainable agriculture production system.

This study was designed to understand fine spatiotemporal ET variation. UAV-based thermal and multispectral data was used to estimate fine spatiotemporal resolution ET. Multispectral (MicaSense Altum) and thermal (ICI-8640P) sensors were mounted on a UAV (DJI Matrice 600 Quadcopter) for monthly data collection during the growing season in 2021 and 2022. Multiple models adapted from methods developed for estimating ET for space-based observation and those derived for aerial measurement were used to compute ET. The data were compared with an eddy covariance tower and sap-flow sensors in the orchard to estimate bias due to the method. In this presentation, we will present preliminary data that compares various models based on measured aerial canopy temperature and multispectral observations with data obtained from other on-farm sensors. We expect that this data will help us design better ET estimation methods for aerial thermal and multispectral imagers and aid modeling of water balance in the region, accounting for farm scale heterogeneities.