The Ganga is one of the world’s most rapidly shrinking rivers, a recent study of 900 rivers in the world has found. One of India’s most culturally and economically important rivers is among 45 in the study that showed a statistically significant reduction in discharge to the ocean.
This group includes the Columbia, Congo, Mississippi, Niger, Paraná, Uruguay and Yenisey.
In 2004, the Ganga had 20 per cent less water than it did 56 years earlier, the study, conducted by the National Centre for Atmosphere Research in Colorado in the US, concluded. This centre belongs to the University Corporation of Atmospheric Research.
In the coming decades, it is likely to shrink even faster, and could even disappear in another 50 years, the study, called Changes in Continental Freshwater Discharge, said.
The waning of the Ganga has huge ecological and economic ramifications: it will reduce the country’s supply of drinking water and irrigation for agriculture. The region will also lose a crucial vehicle for chanelling sewage into the sea.
The Ganges is losing water for two reasons: the glaciers that feed it are in retreat, which means they are losing mass, and rainfall in the region has diminished over the years.
Glaciers all over the world are in retreat because of global warming. Rainfall over north India has gradually fallen over the past five years. Thanks to the El Niño effect and because water and atmosphere above the Indian Ocean have become warmer, the southwest monsoon has weakened.
El Niño is the name for temperature fluctuations on the surface waters of the tropical Pacific Ocean that may be related to global warming. It is linked to floods, droughts and other disturbances around the world.
“Most climate models predict a weaker monsoon over South Asia as carbon dioxide-induced global warming continues,” said Aiguo Dai, one of the scientists who carried out the study.
The Ganges faces an additional burden because its water is being indiscriminately exploitation for irrigation, said Kalyan Rudra, noted river geologist and a former member of Ganga Action Plan, which the Union government launched in April 1985 to reduce pollution levels in the river. It spent more than Rs 900 crore over 15 years, but failed in its mission.
His research confirms the US study’s findings.