# Channel types > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Channel_types > Markdown URL: https://mediated.wiki/source/Channel_types.md > Source: https://en.wikipedia.org/wiki/Channel_types > Source revision: 1181453088 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) A wide variety of [river](/source/River) and [stream](/source/Stream) **channel types** exist in [limnology](/source/Limnology), the study of inland waters. All these can be divided into two groups by using the [water-flow gradient](/source/Stream_gradient) as either *low gradient channels* for streams or rivers with less than two percent (2%) flow gradient, or *high gradient channels* for those with greater than a 2% gradient. ## Low gradient channels See also: [Channel patterns](/source/Channel_patterns) Low gradient channels of rivers and streams can be divided into [braided rivers](/source/Braided_river), wandering rivers, single thread [sinuous](/source/Meander) rivers (meandering), and [anastomosing](/source/Anastomosis) rivers. The channel type developed depends on stream gradient, [riparian](/source/Riparian) vegetation and sediment supply. [Braided rivers](/source/Braided_river) tend to occur on steeper gradients where there is a large supply of sediment for [braid bars](/source/Braid_bar), while single thread sinuous channels occur where there is a lower sediment supply for [point bars](/source/Point_bar). Anastomosing channels are multithreaded, but are much more stable than braided channels and commonly have thick clay and silt [banks](/source/Bank_(geography)) and occur at lower gradients of [stream bed](/source/Stream_bed). Wandering rivers fall between sinuous single thread and braided streams and are relatively stable multi-channel gravel bed rivers. ## High gradient channels High gradient channels of rivers and streams have been divided into riffle-pool (which can cover all of the low gradient channel morphologies discussed above), rapid/plane bed, step-pool and cascade unit morphologies. - [Riffle-pool sequence](/source/Riffle-pool_sequence) channels are composed of migrating [pools](/source/Stream_pool) and transverse [bars](/source/Bar_(river_morphology)) called [riffles](/source/Riffle) and occur on gradients less than 1-2 percent. - [Rapids](/source/Rapids) (also called plane bed, but not to be confused with the plane beds described in sand bed rivers) lack distinct pools and bars but commonly have stone cells or clusters and occur on gradients in the range of 1-5 percent, and have "[whitewater](/source/Whitewater)". - Step-pools are composed of channel-spanning pools and [boulder](/source/Boulder)/cobble steps that cause [subcritical flow](/source/Subcritical_flow) in the pool and [supercritical flow](/source/Supercritical_flow) over the steps. They occur in gradients in the range of 5 and 20%. - [Cascade](/source/Waterfall) units exist at steeper gradients (approx > 10–15 percent) where the channel is dominated by boulders and cobbles and channel spanning pools do not exist. Pocket pools are common. In all four channel types [large woody debris](/source/Large_woody_debris) may strongly influence the channel type. ## See also - [Relief ratio](/source/Relief_ratio) - [Stream gradient](/source/Stream_gradient) - [Stream restoration](/source/Stream_restoration) - [Riparian zone restoration](/source/Riparian_zone_restoration) - [Vladimir Lokhtin](/source/Vladimir_Lokhtin) ## References and further reading - See Church (1992) for more details on low gradient streams and Grant et al. (1990) and Buffington and Montgomery (1997) for more details regarding high gradient streams. - Buffington, J. M., and D. R. Montgomery (1997), A systematic analysis of eight decades of incipient motion studies, with special reference to gravel-bedded rivers, Water Resources Research, 33, 1993-2029. - Church, M. (1992), Channel morphology and topology, in The River Handbook, edited by P. Calow and G. E. Petts, pp. 126–143, Blackwell. - Grant, G. E., F. J. Swanson, and M. G. Wolman (1990), Pattern and origin of stepped-bed morphology in high gradient streams, western Cascades, Oregon, Geological Society of America, Bulletin, 102, 340-352. v t e Rivers, streams and springs Rivers (lists) Alluvial river Braided river Blackwater river Channel Channel pattern Channel types Confluence Distributary Drainage basin Mountain river Subterranean river River bifurcation River ecosystem River source Tributary Streams Arroyo Beck Bourne Burn Chalk stream Coulee Current Stream bed Stream channel Streamflow Stream gradient Stream pool Perennial stream Winterbourne Springs (list) Estavelle/Inversac Geyser Holy well Hot spring list list in the US Karst spring list Mineral spring Ponor Rhythmic spring Spring horizon Sedimentary processes and erosion Abrasion Anabranch Aggradation Armor Bed load Bed material load Granular flow Debris flow Deposition Dissolved load Downcutting Erosion Headward erosion Knickpoint Palaeochannel Progradation Retrogradation Saltation Secondary flow Sediment transport Suspended load Wash load Water gap Fluvial landforms Ait Alluvial fan Antecedent drainage stream Avulsion Bank Bar Bayou Billabong Canyon Chine Cut bank Estuary Floating island Fluvial terrace Gill Gulch Gully Glen Meander scar Mouth bar Oxbow lake Riffle-pool sequence Point bar Ravine Rill River island Rock-cut basin Sedimentary basin Sedimentary structures Strath Thalweg River valley Wadi Fluvial flow Helicoidal flow International scale of river difficulty Log jam Meander Plunge pool Rapids Riffle Shoal Stream capture Waterfall list of waterfalls Whitewater Surface runoff Agricultural wastewater First flush Urban runoff Floods and stormwater 100-year flood Crevasse splay Flash flood Flood Urban flooding Non-water flood Flood barrier Flood control Flood forecasting Flood-meadow Floodplain Flood pulse concept Flooded grasslands and savannas Inundation Storm Water Management Model Return period Point source pollution Effluent Industrial wastewater Sewage River measurement and modelling Baer's law Baseflow Bradshaw model Discharge (hydrology) Drainage density Exner equation Groundwater model Hack's law Hjulström curve Hydrograph Hydrological model Hydrological transport model Infiltration (hydrology) Main stem Playfair's law Relief ratio River Continuum Concept Rouse number Runoff curve number Runoff model (reservoir) Stream gauge WAFLEX Wetted perimeter Volumetric flow rate River engineering Aqueduct Balancing lake Canal Check dam Dam Drop structure Daylighting Detention basin Erosion control Fish ladder Floodplain restoration Flume Infiltration basin Leat Levee River morphology Retention basin Revetment Riparian-zone restoration Stream restoration Weir River sports Canyoning Fly fishing Rafting River surfing Riverboarding Stone skipping Triathlon Whitewater canoeing Whitewater kayaking Whitewater slalom Related Aquifer Aquatic toxicology Body of water Hydraulic civilization Limnology Riparian zone River valley civilization River cruise Sacred waters Surface water Wild river Rivers by length Rivers by discharge rate Drainage basins Whitewater rivers Flash floods River name etymologies Countries without rivers This geomorphology article is a stub. You can help Wikipedia by adding missing information. - [v](https://en.wikipedia.org/wiki/Template:Geomorph-stub) - [t](/source/Template_talk%3AGeomorph-stub) - [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Geomorph-stub) --- Adapted from the Wikipedia article [Channel types](https://en.wikipedia.org/wiki/Channel_types) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Channel_types?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.