Despite a threat of global warming due to climate change, the water level of major rivers fed by the Himalayan glaciers will not drop over the next century, says a new research. The findings of the team led by Dr Walter Immerzeel, scientist at Utrecht University of Netherlands, say that increase in monsoon would prevent the rivers from drying up. Details of the study were published online by ‘Nature Geoscience’.
Significantly, Dr Immerzeel, who is a visiting scientist at the Kathmandu-based International Centre for Integrated Mountain Development), had predicted drop in water levels of the same rivers in an article published in ‘Science’ three year ago.
The new research shows that although size of the glaciers in the basins of Indus and Ganga will decrease in the 21st century, water discharge will however increase, informed ICIMOD.
'We are now using a more advanced glacier model that takes into consideration how slowly glaciers respond to climate change,' the release quoted Dr. Immerzeel.
To understand the impact of climate change on river discharge in Himalayas researchers created computer models of the glacier movements and water balance in two watersheds that vary greatly with regard to the climate and size of the glaciers.
In the eastern watershed—Langtang in Nepal where Ganga has its source — the relatively small glaciers melt quite quickly and the increased water discharge is a result of increase in monsoon rains.
In the western watershed---Baltoro in Pakistan, source of Indus is dryer and colder and has larger glaciers. Increase in discharge there is due to increase in glacial melting.
The study says glacial melting will peak around 2070 and glacial discharge will start to drop. But at that time too increase in precipitation will compensate.
'While results of the research predict a sombre future for the Himalayan glaciers, they offer some good news for water and food security in India, Bangladesh and Pakistan,' said the release.
The researchers stressed that the results should be interpreted with caution as the models of the two basins studied were representative and only relate to a small area of the Himalayas.