NASA has launched two new satellites as part of an ongoing research project aimed at monitoring earth’s freshwater data with hopes the results will aid in global water management strategies. The GRACE-FO mission's satellites were launched into space from California's Vandenberg Air Force Base on board a Falcon-9 rocket, and are set to orbit the Earth at a height of 220km for at least six months. NASA Goddard Space Flight Center’s Dr Matt Rodell is leading a team of researchers using 14 years’ worth of observation data – including past satellite data and geological survey imagery, reports of human activities and irrigation maps – to track global trends in freshwater in 34 regions around the world. Rodell said it’s only through analysis of combined data sets that the scientists were able to get a full understanding of the reasons for Earth’s freshwater changes. "This is the first time that we’ve used observations from multiple satellites in a thorough assessment of how freshwater availability is changing, everywhere on Earth," Rodell said. "A key goal was to distinguish shifts in terrestrial water storage caused by natural variability – wet periods and dry periods associated with El Niño and La Niña, for example – from trends related to climate change or human impacts, like pumping groundwater out of an aquifer faster than it is replenished." While the research project has produced many useful findings, including information about decade-long trends in terrestrial freshwater storage that do not appear to be directly related to human activities, NASA Jet Propulsion Laboratory’s Jay Famiglietti said the new satellite mission is necessary to continue and expand on the research. "What we are witnessing is major hydrologic change," Famiglietti said. "We see a distinctive pattern of the wetland areas of the world getting wetter – those are the high latitudes and the tropics – and the dry areas in between getting dryer. Embedded within the dry areas we see multiple hotspots resulting from groundwater depletion." Famiglietti said while water loss in some regions is clearly driven by warming climate, the research it will require more time and data to determine the driving forces behind other patterns of change. "The pattern of wet-getting-wetter, dry-getting-drier during the rest of the 21st century is predicted by the Intergovernmental Panel on Climate Change models, but we’ll need a much longer dataset to be able to definitively say whether climate change is responsible for the emergence of any similar pattern in the GRACE data," he said.
Such satellite monitoring programmes have been proposed as solutions to some of the most severe water challenges faced by Australia through better monitoring in areas such as the Murray-Darling Basin.
Director of the Australian Centre for Space Engineering Research, Andrew Dempster, assessed the potential for synthetic aperture radar (SAR) to aid water management in the MDB through soil moisture detection. He found an improvement of non-irrigated agriculture of only 0.3% would cover the cost of two satellites.
On 8 May 2018, as part of the 2018-19 Budget, the Australian Government announced the establishment of an Australian Space Agency with ongoing funding starting at $26 million over the next four years. However, no announcements have been made to suggest any upcoming Australian satellite water monitoring schemes.
“The government has announced we are going to have a space agency but they haven't given us any details. The potential problem is that the agency that they end up implementing is not structured such that it can solve these sorts of problems,” Dempster said.