Today – groundwater depletion and how it’s affecting global food production. At a recent science conference, EarthSky spoke to Jay Famiglietti, director of the University of California’s Center for Hydrologic Modeling. He said he’s been using GRACE, a satellite that can trace the movement of water below ground.
Jay Famiglietti: For the first time, we’ve been able to see the ups and downs in water storage all over the planet.
Famiglietti says that, locally, he’s discovered that California’s Central Valley has lost alarming rates of groundwater. He attributes this to mostly to drought.
Jay Famiglietti: There is not as much rainfall, so there is not as much groundwater recharge. Global change is having an impact. We are not getting the snowpack that we used to get.
Famiglietti says the impact is so significant, because California is an agricultural hotbed.
Jay Famiglietti: The Central Valley is responsible for 25% of the food consumed in the United States. Without a sustainable source of water, it will be difficult to continue to grow food at the rates at which we have been growing it.
Famiglietti says he’s found evidence of increasingly parched ground all over the world. He explained that water tables are dropping significantly across northern India, one of the world’s most intensely irrigated regions. He added that, in India, over 100 million people could see this important resource literally dry up, along with their food. Famiglietti spoke more about the GRACE (Gravity Recovery and Climate Experiment) satellite mission.
Jay Famiglietti: This mission has made very important contributions because it allows us to see the human fingerprint of water storage on the continents. Some of the water storage is natural variability, natural seasonal cycling of the water cycle. Some of it is anthropogenic, or human induced, with the groundwater withdrawal.