From 310 Miles Above the Earth, Satellites Weigh Groundwater Lost to Irrigation
Picture a shimmering cube of water three miles high. In the past decade, that much water—nearly the volume of Nevada’s Lake Tahoe—was lost from aquifers under the American High Plains.
That figure doesn’t come from measurements of the water level in wells. Rather, it’s drawn from orbit, in a new study that uses data from NASA’s Gravity Recovery and Climate Experiment (GRACE) spacecraft. GRACE has been weighing groundwater from on high since the late 1990s. But previous GRACE models have overlooked ways in which humans impact aquifers, says study lead author Jose Agustin Brena-Narañjo. “Which, in this case, is irrigation.”