Hydrologic changes Current Affairs - 2019
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According first of its kind study of NASA, India is among hotspots where overuse of water resources has caused sharp decline in availability of freshwater. The study was conducted by scientists from NASA’s Goddard Space Flight Centre by using an array of NASA satellite observations to track global hydrologic changes.
Scientists had used 14 years of observations from Gravity Recovery and Climate Experiment (GRACE) spacecraft mission, a joint project of NASA and German Aerospace Centre, to track global trends in freshwater in 34 regions around the world. This is for first time scientists had used observations from multiple satellites for assessment of how freshwater availability is changing everywhere on Earth.
The study revealed that wetter parts of earth’s were getting wetter and dry areas getting drier due to variety of factors, including human water use, climate change and natural cycles. Areas in northern and eastern India, West Asia, Australia and California (US) are among hotspots where overuse of water resources has caused serious decline in availability of freshwater.
In northern India, groundwater extraction for irrigation of wheat and rice crops has led to depletion, despite rainfall being normal. The groundwater extractions has already exceed recharge during normal precipitation does not bode well for the availability of groundwater during future droughts.