Water Map found by NASA

In times of drought, humans realize just how important water is. However, in the recent years, water shortage has turned out to be something more than a temporary problem. According to NASA, it is likely to be the key environmental challenge of this century. And this widespread issue is driven by the growing overuse of water.

A recent study conducted by NASA revealed a drying out of several regions of the earth between the tropics and the high latitudes, with 19 significant hotspots of water depletion. Led by the agency’s Goddard Space Flight Center in the U.S, the scientists made use of data on human activities to spot locations where the availability of water is changing fast.

It has been found that the northern and eastern parts of India, the Middle East, California, and Australia are among the discovered hotspots where overuse of water resources led to a dramatic decline in the availability of freshwater. Published in the journal Nature, the study found that Earth’s wetland areas were getting wetter and dry areas were getting drier due to several reasons such as human water management, climate change, and natural cycles.

The study made use of 14 years of observations from the US/German-led Gravity Recovery and Climate Experiment (GRACE) spacecraft mission to track global trends in freshwater in 34 regions all over the world. And, according to Jay Famiglietti, a senior water scientist at the NASA Jet Propulsion Laboratory in Pasadena, we are witnessing a major hydrologic change.

In India’s northern part, the extraction of groundwater for irrigation of crops such as wheat and rice resulted in a drastic decline in freshwater despite receiving normal rainfall. “The fact that extractions already exceed recharge during normal precipitation does not bode well for the availability of groundwater during future droughts,” said the authors of the study.

Much of Iraq, Syria, and southern California have witnessed a major decline in freshwater availability owing to over-dependence on groundwater has led to the development of 22 dams on the Tigris and Euphrates rivers over the past few years. This made the regions the biggest hotspots as identified by the study. The Caspian Sea also showed a rapid decline in freshwater owing to the diversion and extraction of water from rivers that feed it, for agriculture and industry, leading to a shrinking shoreline. This is bound to cause major problems throughout its borderlands.

Famiglietti said that while water loss in some regions, such as the melting ice sheets and alpine glaciers, is occurring due to global warming, it will take more time and data to find out the driving forces behind other patterns of freshwater change. Nevertheless, the GRACE satellite observations alone couldn’t tell the researchers what was causing the apparent trends.

According to Jonathan Farr, a senior policy analyst at the charity WaterAid, governments across the world must take note of the findings and take strong actions of preserving water resources and provide fresh water to people in a sustainable manner. He also said that the study is a warning and an insight into a future threat. It is important to ensure that investment in water matches with the pace at which industrialization and farming are taking place.