confluence

thumb|Confluence of the Bhagirathi and [[Alaknanda Rivers at the Ganges in Devprayag, India]] thumb|The same confluence viewed from upstream at a different time; note the swirl of sediment from the Alaknanda River

In geography, a confluence (also conflux) occurs where two or more watercourses join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main stem); or where two streams meet to become the source of a river of a new name (such as the confluence of the Monongahela and Allegheny rivers, forming the Ohio River); or where two separated channels of a river (forming a river island) rejoin downstream from their point of separation.