A new peer-reviewed study has been released that looks to analyze groundwater stresses on the world's 37 largest aquifer systems. Those stresses come in the forms of
climate change and population growth (and their subsidiaries—drought, and irrigation/farming needs).
The impact of quantifying groundwater use based on nationally reported groundwater withdrawal statistics is compared to a novel approach to quantify use based on remote sensing observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission.
The results are troubling. According to the study, 21 of earth's 37 largest aquifers are unsustainable because they have extraction rates that exceed their replenishment rates—these are aquifers where
more water is being taken then replaced.
Among the aquifers with the least sustainable use were two in India, one in China, and California’s Central Valley aquifer, the report said.
Researchers characterized the Central Valley aquifer as “highly stressed” because due it use for irrigation and the drought that has gripped the state.
[...]
Three aquifers in the middle of the United States were being drawn from in a sustainable manner, the second report said. But it warned that the Atlantic and Gulf Coastal Plains aquifer under Florida and the Gulf Coast was being depleted.
When you consider that India and China have populations that make up
more than a third of the world's entire population, having California on this list puts both the drought and also the need for new ideas concerning our relationship to fresh water into perspective.
You can read the whole study here.