The satellite-based water data platform OpenET demonstrates considerable accuracy in measuring evapotranspiration in agricultural settings, according to a new study in Nature Water.
Evapotranspiration — the amount of water lost to the atmosphere through soil evaporation and plant transpiration — is a key measure of water consumption in agriculture and has previously been difficult and expensive to monitor accurately at scale, according to a news release.
A public-private collaboration led by NASA; California State University, Monterey Bay; the Environmental Defense Fund; Desert Research Institute; and HabitatSeven, OpenET uses publicly available data produced by NASA and U.S. Geological Survey Landsat and other satellite and ground-based systems to calculate evapotranspiration rates at the field level, the release said.
The study shows OpenET’s results are particularly reliable for arid regions like California and the Southwest and for annual crops like wheat, corn, soy and rice. The findings highlight the increasing value of OpenET in supporting real-time agricultural water management in regions hardest hit by growing water scarcity.
“Farmers and water managers increasingly need accurate, field-level data on water use,” Maurice Hall, OpenET director and senior adviser for climate-resilient water systems at the Environmental Defense Fund, said in the release. “As reflected in the author list, this study is built on decades of work and helps confirm the vital role OpenET plays in providing a more granular, dynamic picture of water use that can meaningfully inform real-time water decision-making. We look forward to continuing to refine and expand the implementation of OpenET, to ensure farmers, ranchers, and communities can thrive in a world of highly stressed and variable water supplies.”
“It’s truly rewarding to see decades of careful research and hard work by this science community come together, and this study sets a new benchmark for satellite mapping of field-scale evapotranspiration with Landsat,” Forrest Melton, senior research scientist with NASA Ames Research Center, said in the release. “By documenting the accuracy of the OpenET data, I anticipate that this study will further accelerate the already rapid uptake and use of these data to help solve pressing water management challenges and open up new applications and areas of future study.”
Members of OpenET’s growing user base have also voiced support for the platform’s accuracy and efficacy, according to the release.
“The OpenET portal has enabled the Upper Colorado River Commission to evaluate water use from field- to basin-scale in a more efficient, cost-effective, and timely way,” Sara Larsen, deputy director and chief engineer of the UCRC, said in the release. “It has enabled us to fairly evaluate and administer our ongoing interstate water conservation programs such as the System Conservation Pilot Program. These programs work to benefit and protect critical infrastructure in the Upper Basin, as well as to increase local resiliency to drought and climate change. The OpenET Platform and the science behind it are core components of our ongoing efforts.”
Related link: View the full study
