stream order A measure of the position of a stream (defined as the reach between successive tributaries) within the hierarchy of the drainage network. A commonly used approach allocates order ‘1’ to unbranched tributaries, ‘2’ to the stream after the junction of the first tributary, and so on. It is the basis for quantitative analysis of the network.

stream order Measure of the position of a stream (defined as the reach between successive tributaries) within the hierarchy of the drainage network. A commonly used approach allocates order ‘1’ to unbranched tributaries, ‘2’ to the stream after the junction of the first tributary, and so on. It is the basis for quantitative analysis of the network.