Nasa sounds red alert on dipping groundwater
21 Of The World’s 37 Largest Aquifers Have Crossed Tipping Point; 13 In Most-Troubled Category
The world’s largest underground aquifers – a source of fresh water for hundreds of millions of people — are being depleted at alarming rates, according to new NASA satellite data, that provides the most detailed picture yet of vital water reserves hidden under the Earth’s surface.
Twenty-one of the world’s 37 largest aquifers — from India and China to the United States and France — have passed their sustainability tipping points, meaning more water was re- moved than replaced during the decade-long study period, researchers announced on Tuesday. Thirteen aquifers have been put into the most troubled category, signaling a long-term problem that’s likely to worsen as reliance on aquifers grows.
The NASA data is the first detailed assessment which vindicates scientists’ concern that major aquifers are indeed struggling to keep pace with demands from agriculture, growing populations, and industries.
“The situation is quite critical,” said Jay Famiglietti, senior
North Korea has been hit by its worst drought in 100 years, the state-run news agency said on Tuesday, adding 30% of the paddy fields have dried up. This has sparked fears of food shortage in the country water scientist at NASA’s Jet Propulsion Laboratory in California.
Underground aquifers supply 35% of the water used by humans worldwide and its demand increases in times of drought. Rain-starved California is currently tapping aquifers for 60% of its water use as its rivers and above-ground reservoirs dry up, a steep increase from the usual 40%. The aquifers under the most stress are in poor, densely populated regions, such as north-west India, Pakistan and North Africa, where alternatives are limited and water shortages could quickly lead to instability.
The researchers used NASA’s GRACE satellites for the study, spanning from 2003-2013, to take precise measurements. The satellites detected subtle changes in the Earth’s gravitational pull, noting where the heavier weight of water exerted a greater pull on the orbiting spacecraft.
The world’s most stressed aquifer — defined as suffering rapid depletion with little or no sign of recharging — was the Arabian Aquifer, a water source used by more than 60 million people.