Tributary
Videos
A tributary, or an affluent, is a stream that flows into a larger stream or lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem into which they flow drain the s
Nam Khan flows into the Mekong at Luang Prabang in Laos.
At Harpers Ferry, West Virginia, looking downstream, the Shenandoah River (bottom right) meets the Potomac River, which flows from bottom left to top right, making the Shenandoah a right tributary of the Potomac.
![The Mekong is a trans-boundary river, originating in the Tibetan Plateau. Its upper tributary river systems (e.g. ngom chu [zh]) are restricted to nar](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a0/Mekongbasin.jpg/500px-Mekongbasin.jpg)
The Mekong is a trans-boundary river, originating in the Tibetan Plateau. Its upper tributary river systems (e.g. ngom chu [zh]) are restricted to narrow gorges, but the tributaries that feed its lower reaches (e.g. the Mun River) cover larger areas.
Amazon River
Videos
The Amazon River in South America is the largest river by discharge volume of water in the world, and the second-longest or longest river system in the world, a title which is disputed with the Nile.
Satellite image of the Amazon Delta
Old drawing (from 1879) of Arapaima fishing at the Amazon River. The arapaima has been on Earth for at least 23 million years.
Amazon tributaries near Manaus
Amazonas state