Scientists studying deltas show how they may be able to predict where destructive changes in a river's course may occur.
A delta forms when a river meets a sea or ocean. Deltas are extremely fertile for crops, and home to over half billion people and several mega-cities.
An avulsion - where the flow of water through a delta changes its course - can be sudden and unpredictable, often catching communities off-guard. When it happens, the river floods the neighbouring areas, threatening livelihoods and destroying valuable farming land.