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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Research Project #443250

Research Project: Improving Agricultural Consumptive use Estimates within the Lower Colorado River

Location: Water Management and Conservation Research

Project Number: 2020-13660-009-009-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 1, 2022
End Date: Jul 31, 2025

The project will enhance estimation accuracy of crop evapotranspiration for irrigated districts along the Lower Colorado River within the Lower Colorado Annual Summary of Evaporation and Evapotranspiration (LCRAS) Program.

The project will utilize a method previously developed for the Yuma area based on combining crop type maps with satellite images collected every 3-5 days. Vegetation index (VI) data will be extracted from the images throughout the year for fields of known crops using Google Earth Engine (GEE) processing and locally written R scripts. The time-series VI values will be transformed to crop growth stage durations for fields of selected crops and combined with existing crop coefficients to return daily and seasonal ET values. Scripts and techniques used to implement the method will be fully documented and compiled into an open-source toolset and will be applied routinely in the LCRAS program.