NASA/USGS satellite sees green-up along Colorado River's Delta after experimental flow

Although most of the water soaked into the ground in the 37 miles below the dam, the river's surface flow reached areas farther downstream that had been targeted for restoration, and groundwater revived vegetation along the entire route to the sea.

"Remote sensing with satellites such as Landsat and sensors such as MODIS allows scientists to conduct a range of studies they wouldn't otherwise be able to," said Karl Flessa, the co-chief scientist of the Minute 319 Science Team studying the hydrologic and biologic effects, and a geosciences professor at the University of Arizona in Tucson.

It's just one of the tools scientists are using, along with on-the-ground monitoring, to detect changes in the river channel, surface water, groundwater, plant growth, and habitat for resident marsh birds and migratory birds.

"In addition to remote sensing, ground-based geophysical methods such as time-lapse gravity maps provide information about the change in groundwater storage, which ultimately supports riparian vegetation," said Jeff Kennedy, USGS hydrologist and participant in the study.

The Minute 319 pulse flow was the result of significant cooperation between a large group of partner organizations and agencies in the U.S. and Mexico.

With so many interested parties, and water such a precious resource, scientists will continue to monitor the lower Colorado River Delta's vegetation and hydrological response to the pulse flow, Flessa said. Using greenness data collected both from the ground and from satellites, researchers will investigate the long-term impacts to groundwater, and they'll continue to study whether new trees and shrubs take root due to the flow. They will also study how the new vegetation affects birds migrating along the Pacific Flyway.

"There's hope that we could release a pulse of water below Morelos Dam again," Flessa said.

Using data from NASA/USGS satellite Landsat 8, scientists have measured how vegetation in the Colorado River Delta has responded to the pulse of water released in March 2014 as part of the Minute 319 bi-national agreement.

(Photo Credit: NASA SVS)

On March 23, 2014, water was released from the Morelos Dam on the US-Mexico border, as part of the "Minute 319" agreement. Researchers studying the effects of the 105,000-acre-foot flow, using Landsat 8 and other tools, saw a resulting "green-up" of the lower Colorado River Delta.

(Photo Credit: Karl Flessa, University of Arizona)

Source: NASA/Goddard Space Flight Center