The Colorado River Basin provide weewee to 40 million Americans and 4 million Acre of cultivated land in seven western state . Unfortunately , recent analysis has bring out that over the last nine year , the groundwater from the basin is go away much more rapidly than was anticipate . The collaborative sketch was direct by Jay Famiglietti of Jet Propulsion Laboratory and the newspaper publisher was published inGeophysical Research Letters .
info regarding the amount of piddle fall behind was collected via NASA ’s Gravity Recovery and Climate Experiment ( GRACE ) satellite between December 2004 and November 2013 . The data intimate that drouth have contributed to a loss of 64.8 km3of fresh water . Disturbingly , over 75 % of that red ink appears to have number from groundwater source , meaning it is getting consume at an unprecedented and alarming rate .
" We do n’t have it away exactly how much groundwater we have leave , so we do n’t recognise when we ’re going to track down out , " go source Stephanie Castle tell in apress release . " This is a lot of weewee to mislay . We thought that the motion picture could be jolly bad , but this was shocking . ”
Unfortunately , a lack of consistent record keeping has made tracking weewee layer hard . urine levels above ground are modulate at the Union level by the U.S. Bureau of Reclamation and are well - documented . Groundwater source are managed at the state horizontal surface , and there are not uniform policy in place and the phonograph record are not complete .
" There ’s only one way to put together a very large - area study like this , and that is with satellites , " Famiglietti explained . " There ’s just not enough information available from well datum to put together a consistent , washbowl - wide painting . ”
GRACE is able to track the differences in groundwater volumes based on change in multitude , which slightly alters the gravitative attraction in that region . These numbers were compared with the Bureau of Reclamation ’s data on above ground water sources , grant the investigator to determine the fluctuation of groundwater volume over time .
” The Colorado River Basin is the H2O lifeline of the westerly United States , " said Famiglietti . " With Lake Mead at its low level ever , we wanted to research whether the basin , like most other area around the mankind , was relying on groundwater to make up for the modified surface - water supplying . We found a surprisingly high and long - term trust on groundwater to bridge the gap between supply and requirement . ”
Lake Mead is the enceinte reservoir in the part andset a recordlast month for the lowest water level since it was fill in 1937 . increase scarcity of resources could lead to massive alteration of water allocationas before long as April 2016 .
" Combined with declining snowpack and universe increase , this will belike jeopardise the long - terminal figure ability of the drainage basin to fill its water supply allocation committal to the seven washbowl states and to Mexico , " Famiglietti pronounce .
