Like many other researchers, environmental engineering professors Erin Hestir and Joshua Viers of the University of California, Merced, are trying to quantify water use in the San Joaquin Valley.
The difference is they are doing it from the sky.
Through NASA’s applied sciences program, their team will leverage the power of Earth-orbiting satellites and drones to gather data with high spatial and temporal resolution and then analyze it to help water resource managers make better-informed decisions.
The NASA team is collaborating with Point Blue Conservation Science, a nonprofit science team based in the San Francisco Bay Area that seeks solutions to address biodiversity loss from climate change.
Hestir said the project “will help us better balance water allocation not only for human uses such as agriculture, which are really important, but also to make sure we are sustaining biodiversity and ecosystem functioning critical to the valley.”
Water is a limited resource across the West. Over the past 100 years, an extensive system of reservoirs and water conveyance structures have been engineered to support the needs of human communities, agriculture and ecosystems.
Model projections suggest water may become even more limited as increasing frequency and severity of drought test water management programs.
“The Central Valley… is a nexus for water resources and epitomizes the challenges facing water systems in the West,” the researchers wrote in their proposal.
Another partner in the project is Grassland Water District, which seeks to maximize the use of limited water available for ecosystem functioning, as well as waterfowl and shorebird habitat. The district, located in Merced County, manages more than 75,000 acres of wetlands for the Grassland Resource Conservation District.
Effectively quantifying water use is particularly important now that the state’s Sustainable Groundwater Management Act has gone into effect. The act requires all groundwater users to form Groundwater Sustainability Agencies and develop Groundwater Sustainability Plans, or GSPs, for groundwater basins.
Although managed wetlands are an essential component of water use planning and budgeting, there are limited data about the extent and magnitude of managed flooding—often for the purposes of providing habitat for waterfowl and supporting local duck clubs—that can be used to inform water budget models.
Satellites have been able to track surface water in different wetlands across the Central Valley, but not yet the depth of the water. That’s where UC Merced and Point Blue come in. A central component of the NASA-funded project is developing algorithms that mine satellite data to determine the extent, depth and duration of flooded fields and wetlands.
“The ability to generate data on water depth to populate wetland water budgets…will increase the capacity to inform GSPs in a cost-effective way,” wrote Ric Ortega, general manager of the Grassland Water District.
“Rather than assuming there is water in the wetlands because it’s been released from the rivers,” Hestir said, “we’re going to try to use new, cutting-edge NASA technology, including space-based sensors as well as drone sensors to create three-dimensional representations of the landscape.”
She said, “That will help us understand how much water is truly in the wetlands, which will give people more information when it comes to deciding on how to balance all the different needs.”
The project will also help answer important questions, such as how changes in land management will affect water use and how water use varies across extreme events, particularly drought and flood. This research builds on more than a decade of water research led by UC Merced that is specific to the San Joaquin Valley and its watersheds.
“In our dry years, every drop counts,” Hestir said.
(This story was originally published by the University of California, Merced.)
