Throughout history, important cities around the world have flourished along river banks. But rivers can also be destructive forces. They routinely flood, and on rare occasions, they can abruptly shift pathways.
These “channel-jumping” events, which are called avulsions, have caused some of the deadliest floods in human history. Avulsions on China’s Yellow River killed over 6 million people in the late 19th and early 20th centuries. Similar events have been linked to the decline of Mesopotamian civilization along the Tigris and Euphrates rivers in what is now Iraq, Kuwait, Turkey and Syria.
