Nevada farmer Denise Moyle will use OpenET to plan the irrigation of her alfalfa fields. Image Credit: Photo courtesy of Glow by G Photography
Building on more than two decades of research, a new web-based platform called OpenET will be available shortly NASA Data in the hands of farmers, water managers and conservation groups to accelerate improvements and innovations in water management. OpenET uses publicly available data and open source models to provide satellite-based information on evapotranspiration (the “ET” in OpenET) in areas of just a quarter of a hectare and at daily, monthly and annual intervals.
Evapotranspiration is the process by which water is transferred from land to the atmosphere by leaving the soil (evaporation) and losing water through plant leaves and trunks (transpiration). Evapotranspiration is an important measure of how much water is used or “used” by agricultural crops and other plants.
In the arid western United States, where most of the water used by humans for irrigation is used to grow crops, an accurate measure of evapotranspiration is critical to balance water supplies and demands. Until OpenET, there was no operating system for measuring and distributing evapotranspiration data on the scale of individual fields in the western United States. OpenET will be open to the public for the next year, providing evapotranspiration data in 17 western states.
Evapotranspiration is the process by which water is transferred from land to the atmosphere by leaving the soil (evaporation) and losing water through plant leaves and trunks (transpiration). Photo credit: NASA / Goddard Space Flight Center Conceptual Imaging Lab
“What OpenET offers is an opportunity for people to better understand their water use, and most importantly their water loss through evapotranspiration,” said Denise Moyle, an alfalfa farmer in Diamond Valley, Nevada, and OpenET employee. “Providing better information to farmers and other water managers is the greatest value of OpenET.”
The OpenET platform is developed in a unique collaboration between scientists, farmers and water managers from across the western United States, as well as software engineers who specialize in data access and visualization for large earth observation datasets.
OpenET is led by NASA, the nonprofit Environmental Defense Fund (EDF), the Desert Research Institute (DRI) and the data application developer HabitatSeven. With funding from the Water Funder Initiative and in-kind contributions from Google Earth Engine, OpenET primarily uses satellite datasets from the Landsat program, a partnership between NASA and the US Geological Survey (USGS). Additional data comes from NASA’s Terra and Aqua satellites, the National Oceanic and Atmospheric Administration’s (NOAA) GOES satellite series, and others.
“OpenET will enable farmers and water managers in the West to create more accurate water budgets and identify stress, resulting in a more resilient system for agriculture, people and ecosystems,” said Maurice Hall, director of EDF’s Western Water Program. “We envision OpenET improving the playing field by making the same trusted data available to all types of users, from smallholders to regional water planners.”
California Delta Water Master Michael George is responsible for managing water rights in the Sacramento-San Joaquin River Delta, which provides drinking water to more than 25 million Californians and irrigates 3 million acres of farmland. For him, the development of OpenET is an exciting opportunity for the future of water in the west.
A screenshot of the OpenET interface. Photo credit: NASA
“OpenET is a game changer in water management,” said George. “It will help landowners and water managers in the Bay Delta save millions of dollars otherwise spent on water meters to more accurately measure water usage as required by state law.”
Forrest Melton, program scientist at NASA’s Western Water Applications Office, said OpenET data will not only help Delta farmers save costs, but also improve water management in the area. He is also a member of NASA’s Ames Research Center Earth Science and Technology Research Cooperative (ARC-CREST).
“The importance of careful, data-driven water management in the delta and other regions cannot be emphasized enough,” he said. “The delta not only provides water for drinking and growing food, it also provides a critical habitat for endangered species. It is almost impossible for a water manager to balance all of these requirements without accurate and timely data. ”
The OpenET team is currently working with water users on several case studies in the West. In California’s Central Valley, the Rosedale-Rio Bravo water storage district is already using OpenET data as the basis for an online water billing and trading platform to help farmers in the district sustainably manage groundwater. In Colorado, high altitude ranchers will use OpenET to experiment with different irrigation strategies to conserve water.
Justin Huntington, a member of the Landsat science team at DRI, emphasized the importance of getting such early feedback on the OpenET system from future users. “Working closely with farmers and water managers to design OpenET has given us valuable insight into how best to make ET data available to support water management in Diamond Valley and other basins to the west,” he said.
Because the OpenET system uses open source software and open data sources, it will help water managers set an agreed level for evapotranspiration in agricultural areas, Melton said. Different estimates of evapotranspiration had previously been confusing for water managers, he said, explaining that water users and managers currently have to evaluate a variety of methods for measuring water use and evapotranspiration, often leading to different numbers and debates accuracy.
OpenET offers a solution to these debates, said project manager Robyn Grimm. “OpenET brings together several established methods of calculating evapotranspiration from satellite data on a single platform so that anyone who makes decisions about water can work with the same playbook and use the same consistent, trusted data,” said Grimm, who is also a senior manager at EDF.
The need for a resource like OpenET is also pushing beyond California and across the American West, Melton said.
“Our water supplies in the west are vital to the supply of the country and beyond, and yet these supplies are under increasing stress,” Melton said. “OpenET will provide the data we need to address the water scarcity challenge in many agricultural regions around the world and ensure we have enough water for generations to come.”
