stream order

Stream order is a way to categorize rivers and streams based on how they connect to each other. Imagine small streams as the beginning of a network; these are called first-order streams. When two first-order streams join, they form a second-order stream. When two second-order streams come together, they create a third-order stream, and so on. If a stream of one order meets a larger one of the same order, the stream's order stays the same. This system helps scientists describe and understand the hierarchy and complexity of river systems.