NASA Satellite May Help California Farmers Combat Drought in the Future

Drought continues to spread across California. In fact, about 60 percent of the state is experiencing "exceptional drought," which is the U.S. Drought Monitor's most dire classification. Now, NASA scientists are launching a new satellite that could help farmers and water managers worldwide.

Currently, there's no ground or satellite-based global network that monitors soil moisture at a local level. This means that it's difficult to estimate how conditions might change, and how water managers should respond accordingly. NASA's Soil Moisture Active Passive (SMAP) satellite could change that, though.

SMAP, which is scheduled to launch this winter, uses two microwave instruments to monitor the top two inches of soil on Earth's surface. Together, the instruments create soil moisture estimates with a resolution of about six miles; in fact, the satellite will map the entire globe every two or three days.

"Agricultural drought occurs when the demand for water for crop production exceeds available water supplies from precipitation, surface water and sustainable withdrawals from groundwater," said Forrest Melton, one of the researchers, in a news release. "Based on snowpack and precipitation data in California, by March we had a pretty good idea that by summer we'd be in a severe agricultural drought. But irrigation in parts of India, the Middle East and other regions relies heavily on the pumping of groundwater during some or all of the year."

Underground water resources are difficult to manage; in fact, farmers who rely on groundwater have fewer indicators of approaching shortfalls. This means that SMAP could be a huge resource for farmers so that they can prepare for potential droughts; they can change irrigation patterns or delay planting or harvesting in order to give plants the best shot at success.

"Scientists see tremendous potential in SMAP," said Melton. "It is not going to provide field-level information, but it will give very useful new regional observations of soil moisture conditions, which will be important for drought monitoring and a wide range of applications related to agriculture. Having the ability provided by SMAP to continuously map soil moisture conditions over large areas will be a major advance."

Want to learn more about SMAP? Check out NASA's website.