Landsat: A Space Age Water Gauge

NASA has released a video illustrating an innovative satellite-based method that maps agricultural water consumption. The new mapping tool, based on Landsat satellite data, received a prestigious Innovations In American Government award from Harvard University’s Ash Institute on September 14.

Water specialists Rick Allen, Bill Kramber and Tony Morse use Landsat thermal band data to measure the amount of water evaporating from the soil and transpiring from plants’ leaves – a process called evapotranspiration. Evapotranspiring water absorbs energy, so farm fields consuming more water appear cooler in the thermal band. The Landsat observations provide an objective way for water managers to assess on a field-by-field basis how much water agricultural growers are using. The team’s measurements have even been used to help settle water rights conflicts in court.

In addition to featuring interviews and Landsat imagery, the video demonstrates visually how Landsat captures images in both the visible spectrum and thermal band, and shows a resulting evapotranspiration map created using the mapping tool.

Landsat is a joint program of NASA and the US Geological Survey.