What term is used to refer to the streams formed when two second order streams merge?

When two second order streams merge, they create a stream classified as a third order stream. This classification follows the Strahler stream order system, where the order increases based on the confluence of streams.

In this system, a first order stream is defined as a stream with no tributaries. When a first order stream merges with another first order stream, they form a second order stream. Consequently, when two second order streams merge, the resulting stream is categorized as third order. This hierarchical classification system is crucial for understanding the structure and dynamics of river systems, illustrating how streams grow in complexity as they combine with others. Thus, identifying the correct order of a stream after merger is essential for hydrology, ecology, and water resource management.