Stream Order

{
  "id": "MLC-T-ENV-026956",
  "term": "Stream Order",
  "field": "Environment",
  "definition": "1. A stream classification system in which the headwater channel is of order 1, and when two channels of the same order join, they create a channel of one higher order (e.g., 1+1=2; 1+2=2; 2+2=3; etc.).\n\n2. Stream size, based on the confluence of one stream with another. 1st order streams are the origin or headwaters. The confluence or joining of two 1st order streams forms a second order stream, the confluence of two 2nd order streams forms a 3rd order stream, and so on.\n\n3. A classification based on stream/tributary relationships. The uppermost channels in a drainage network (i.e., headwater channels with no upstream tributaries) are designated as first-order streams down to their first confluence. A second-order stream is formed below the confluence of two first-order channels. Third-order streams are created when two second-order channels join, and so on. Note that the intersection of a channel with another channel of lower order does not raise the order of the stream below the intersection (e.g., a fourth-order stream intersecting with a second-order stream is still a fourth- order stream below the intersection).",
  "subject": "Water",
  "references": [
    "Watershed Protection Glossary",
    "Wadeable Streams Assessment Glossary of Terms",
    "N-STEPS Online Glossary of Terms; NSTEPS Online Glossary of Terms"
  ],
  "url": "https://mlchart.com/terminology/environment/stream-order/"
}