The trend has caused some rivers across the region to migrate from their established channels that humans have used for thousands of years.

These roving waterways, pushed off course by intense bursts of rainfall and violent sediment discharge, have most severely affected the Himalayan state of Arunachal Pradesh.

A number of hamlets in that state have been severely flooded in recent years — many of them counted as among the oldest human settlements on Earth.

A study found some rivers shifted more than a mile, and some riverside villages simply vanished as a result.

Geologist S.K. Patnaik, like many other scientists throughout the region, blames the phenomenon of river channel migration on more severe rainfall patterns that have affected the region over the last few decades.

“Under normal climatic conditions, rainfall would have been well-distributed throughout the year,” he says. “Now due to climate change, the pattern has changed. It has become erratic.”

While overall precipitation has not increased dramatically in recent years, the rainfall is now typically more concentrated in intensity and duration. Over time, the impact of these repeated “cloudbursts” has had the effect of shifting river pathways permanently.

According to one survey of geological records between 1969 and 2009, some rivers in the region have moved by more than a mile. As a result, hundreds of people have been left homeless.

Experts also warn that many of the state’s plant and animal life has been put at risk. Arunachal Pradesh is considered one of the most biologically diverse places in the world.

But some experts have cautioned against drawing any conclusions given the limited amount of data available.

Photo: Foto Morgana - Flickr