River avulsions, which occur when a river jumps its course and forms a new channel, will become much more frequent as a result of sea-level rise. Researchers at Caltech found that the intensity of these hazards will depend on the rate of sea-level rise and the sediment load carried by the river.

Even though avulsions are a natural phenomenon, they can turn into catastrophic and deadly flooding disasters. For example, river avulsions caused the 1887 Yellow River floods and the 1931 China floods which collectively killed about six million of people.

“A river avulsion is a catastrophic flood that is also crucial for sustaining coastal land,” said study lead author Austin Chadwick. “But the question is: how will sea-level rise affect these catastrophic floods?”

A 2014 report from the Intergovernmental Panel on Climate Change (IPCC) projected that the global average sea level could rise by as much as three feet by the end of this century. Scientists have been investigating how this would affect avulsions on deltas where a river meets an ocean or lake.

“Avulsions are the earthquakes of rivers,” said study co-author Professor Michael […]