“The Godavari, Krishna and Cauvery rivers have experienced dramatic changes in flow due to the construction of dams, anthropogenic contamination and other activities, National Geophysical Research Institute (CSIR-NGRI) senior scientist Dr S. Masood Ahmad said here on Sunday.
“The Godavari would require significant intervention to protect its ecosystems and the people, who are mainly dependent on its river basins,” he added. (About 135 million people inhabit the river basins of the Godavari and Krishna.)
Dr Ahmad was speaking on how climate change would seriously affect the quality and quantity of water in Indian rivers particularly due to extreme events like floods and droughts, seawater intrusion and anthropogenic contamination.
However, the impact of climate change on South Indian rivers is relatively less compared to the Himalayan rivers like the Ganges, he observed. Water discharge in South Indian rivers is dependent on monsoon rainfall, whereas Himalayan rivers have significant contribution from melting snow,” he added.
Global warming therefore has a bigger effect on Himalayan rivers than South Indian (peninsular) rivers, he said. Climate change is expected to reduce the discharge of snow and ice melt water in the large Himalayan rivers (Ganges, Brahmaputra, Indus and Yangtze), These rivers are crucial to ensure food security for hundreds of millions of people in Asia.
Dr Ahmad said recent studies had proved that the world will experience changes in river discharge. Some major rivers will experience significant increases in flood flows, while some others are likely to experience a drastic reduction in flow.
“We plan to conduct a group effort to use sedimentary archives, both onshore and offshore, to trace the evolutionary history of Asian big river systems,” Dr Masood Ahmad said.
Even to understand the effects of this change there was an urgent need for the generation of new data and aquifer modeling of river basins in India, he pointed out.
Eminent earth and water scientists from around the world will soon converge on the city-based National Geophysical Research Institute (CSIR-NGRI) for a better understanding of the evolution of these river systems.
The Krishna-Godavari (KG) and Kaveri basins, for instance, present fascinating examples of hydrogeological and ecological settings. The process of precipitation, recharge and storage as well as the hydrodynamics of water flow of these rivers remain quite ambiguous and require detailed investigations due to the changing climate, Dr Ahmad said.