tributaries
They join together; Many small streams becomes on big one and the big ones lead to the river
With other streams or tributaries joining, a stream's flow of water increases until it can be considered a river. For example, the mighty Mississippi starts out as a trickle of water near the Canadian border. Many similar trickles begin to join it and the flow increases.
In many cases rivers begin at a source that has snow fall. The run off from melting snow can be the beginning of a river. Small streams built upon the items mentioned above can combine with other small streams and thus become the beginning of a river.
It begins at its source and ends at the mouth of the river.A river might begin in a lake, in an underground water reservoir, as melting water from a glacier or as many small streams come together and form a bigger stream you might call a river.
A tributary
Many rivers and small streams flow into the Ohio River. Some of the major ones are: Allegheny River Monongahela River Wabash River Tennessee River Cumberland River Muskingham River Source: Riverlorian.com
Small contributors to a big river are often referred to as "tributaries." These smaller streams or rivers flow into a larger river, contributing to its water flow and drainage basin. Together, tributaries and the main river form a river system, which plays a crucial role in the ecosystem and hydrology of the region.
The Hudson River used the Mohawk River and other small streams to connect to the Hudson River at Albany.
There are no rivers in Denmark, only small streams
The beginning a brook or a river is called the source. Most of the time the source is rather small and nondescript.
A river can form through ice melting from the mountains or through rainfall that collects in wetlands. Small streams that flow downhill join up and make larger streams which also combine to form rivers.
A stream or brook can get bigger and become a river.