A research by the University of Edinburgh has unveiled that volcanic eruptions can affect the flow of water in major river systems. This can reduce rainfalls in different regions. It is known for many years that massive volcanic eruptions have brought changes on earth in terms of different terrains and nature units.

The researchers during the study have found that ash and debris from the volcanoes shoots up in the atmosphere sometimes blocking out the sun and changes the flow of water of the main river systems in the world.

It has been seen in the Nile, Congo and Amazon rivers. At these places, water volume has reduced by as much as 10% of major volcanic eruptions. Edinburgh researchers Gabriele Hegerl and Carley Iles said that it was already known that the eruptions affect the amount of rainfall in the world. But they were not having any idea of what extent these occurrences can affect the flow of water in rivers.

The researchers have studied yearly water flow of 50 rivers in different parts of the world and they have compared them with the occurrence of volcanic eruptions. “All of these impacts come about because volcanoes inject particles -- sulfate aerosols -- high up into the atmosphere, and these spread out and reflect sunlight back out into space”, said the researchers.

"As well as affecting river flow and rainfall, volcanic eruptions have a cooling effect on climate," Iles said.