Where river join is termed a Confluence.
con·flu·ence
(knfl-ns)n.1.a. A flowing together of two or more streams.
b. The point of juncture of such streams.
c. The combined stream formed by this juncture.
2. A gathering, flowing, or meeting together at one juncture or point: "A confluence of negative events conspired to bring down bond
Other streams or lakes that joins a main river is a tributary
The join of a small river (a tributary) joins a larger river (the main river) is called a confluence.
The term used to describe one river emptying into another is "tributary." A tributary is a smaller stream or river that flows into a larger one, contributing its water to the main river system. The point where the tributary joins the larger river is called the confluence.
The smaller stream is a tributary of a larger stream, river or lake.
The Langani river is a tributary to the Kafue river.
Creek
The main river that flows directly through the town is the river Severn. The Reabrook is a small tributary that joins the Severn close to the English bridge near to the town centre.
A tributary, it contributes to the flow of the main river. kool-Aid grape slurpy
A tributary or affluent is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. ... A confluence, where two or more bodies of water meet together, usually refers to the joining of tributaries.
It is called a tributary
When other rivers or lakes join to the main river . It is called the tributary .
After a tributary, the next stage in a river system is typically the main river or parent river into which the tributary flows. This main river may collect water from multiple tributaries, contributing to its overall size and flow. Eventually, the main river may lead to larger bodies of water, such as lakes, seas, or oceans.