Rivers all have a system and it is to recirculate the earth's water continuously. An example is, every spring in Canada, our rivers are given more water from the snow that has melted from the north. By doing this, many times, it forms patterns and it is called drainage patterns. River can carve two different types of patterns. It can be dendritic or trellis. These patterns are what makes up our different landforms and rocks.

Dendritic drainage is a drainage pattern looks like a carvings like trees. It is created when the rivers cross a slope over a basic type of rock. This pattern is the most common drainage pattern.
This is an example of a dendritic drainage pattern.

A trellis drainage pattern is a rectangular drainage pattern created when the rivers flow through changing bands of hard and soft rock. This often happens when a big river cuts through fold mountain ridges. This pattern is not as usual as a dendritic pattern. An example can be the Appalachian Mountians of eastern North America.

A trellis drainage pattern is a rectangular pattern. This is an example.
By: Peggy