What is the name given to the collection of smaller streams that contribute to a main river?

The term given to the collection of smaller streams that feed into a main river is known as tributaries. Tributaries contribute to the flow and volume of water in the main river, and they play a crucial role in the overall hydrology of a watershed. They can vary in size and length, and their presence can significantly influence the landscape and ecology of the river system.

In contrast, sources refer to the origin points of a river, whereas drainage systems encapsulate the entire network of interconnected lakes, rivers, and streams that drain an area. Catchment areas are the regions where rainwater collects and drains into a particular river or water body, but they do not specifically refer to the smaller streams themselves. Understanding the role of tributaries is essential for grasping how river systems function and how they impact the environment around them.