Experts warn of more floods in northern IndiaSeptember 13th, 2008 - 11:09 am ICT by IANS
New Delhi, Sep 13 (IANS) With over 2.7 million people affected by the floods caused by the change of course of the Kosi river in Bihar, researchers have now warned of more floods in northern India in coming years following changing stream flow patterns in the Himalayan rivers. The researchers from Pune University and College of Military Engineering, Pune, found an increase in the number of ‘high-magnitude flood’ events in four rivers - Chenab, Ravi, Satluj and Beas in northwestern Himalayas in the last four decades.
The researchers analysed the discharge of glacial melt into these rivers and found changing water flow patterns in the river due to global warming.
“The high-magnitude events in Himalayan rivers are generally in monsoons; hence they may lead to floods in plains too,” researcher M.R. Bhutiyani, professor at the College of Military Engineering, told IANS.
Bhutiyani said a “high magnitude flood event” is defined as an event when river flow at a particular point exceeds its average value.
“The data analysis shows that there was a significant number of high magnitude flood events in the rivers in the last four decades and the frequency of such events has been increasing,” he said.
The researchers found that due to global warming smaller glaciers in the Himalayas have receded at a relatively faster rate than the larger ones. This may ultimately lead to their disappearance in the near future.
“It is the glacier contribution which is going to be impacted because of global warming. There will be variations in response to the monsoon rainfall. Glaciers, which acted as natural regulators of discharge, will no longer play an important role in the hydrological regime of such basins,” Bhutiyani said.
The researchers found a significant increase in the glacial discharge in the Chenab and Satluj rivers, attributing this to a larger number of glaciers in the basin being on the retreat.
Discharges in the Beas and Ravi rivers do not seem to be significantly affected as the contribution of glacial melt in northwest Himalayas is far lower.