title: The Blurred Line between Form and Process: A Comparison of Stream Channel Classification Frameworks.
abstract: Stream classification provides a means to understand the diversity and distribution of channels and floodplains that occur across a landscape while identifying links between geomorphic form and process. Accordingly, stream classification is frequently employed as a watershed planning, management, and restoration tool. At the same time, there has been intense debate and criticism of particular frameworks, on the grounds that these frameworks classify stream reaches based largely on their physical form, rather than direct measurements of their component hydrogeomorphic processes. Despite this debate surrounding stream classifications, and their ongoing use in watershed management, direct comparisons of channel classification frameworks are rare. Here we implement four stream classification frameworks and explore the degree to which each make inferences about hydrogeomorphic process from channel form within the Middle Fork John Day Basin, a watershed of high conservation interest within the Columbia River Basin, U.S.A. We compare the results of the River Styles Framework, Natural Channel Classification, Rosgen Classification System, and a channel form-based statistical classification at 33 field-monitored sites. We found that the four frameworks consistently classified reach types into similar groups based on each reach or segment's dominant hydrogeomorphic elements. Where classified channel types diverged, differences could be attributed to the (a) spatial scale of input data used, (b) the requisite metrics and their order in completing a framework's decision tree and/or, (c) whether the framework attempts to classify current or historic channel form. Divergence in framework agreement was also observed at reaches where channel planform was decoupled from valley setting. Overall, the relative agreement between frameworks indicates that criticism of individual classifications for their use of form in grouping stream channels may be overstated. These form-based criticisms may also ignore the geomorphic tenet that channel form reflects formative hydrogeomorphic processes across a given landscape.
authors.affiliation: Department of Watershed Sciences, Utah State University, Logan, UT 84322-5210, United States of America.
authors.forename: Alan
authors.initials: A
authors.lastname: Kasprak
authors.affiliation: Department of Watershed Sciences, Utah State University, Logan, UT 84322-5210, United States of America.|Ecology Center, Utah State University, Logan, UT, 84322-5210, United States of America.
authors.forename: Nate
authors.initials: N
authors.lastname: Hough-Snee
authors.affiliation: Fish Ecology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA 98112, United States of America.
authors.forename: Tim
authors.initials: T
authors.lastname: Beechie
authors.affiliation: Eco Logical Research, Providence, UT, United States of America.
authors.forename: Nicolaas
authors.initials: N
authors.lastname: Bouwes
authors.affiliation: School of Environment, University of Auckland, Auckland, New Zealand.
authors.forename: Gary
authors.initials: G
authors.lastname: Brierley
authors.affiliation: Department of Watershed Sciences, Utah State University, Logan, UT 84322-5210, United States of America.|Eco Logical Research, Providence, UT, United States of America.
authors.forename: Reid
authors.initials: R
authors.lastname: Camp
authors.affiliation: Department of Environmental Sciences, Macquarie University, Sydney, Australia.
authors.forename: Kirstie
authors.initials: K
authors.lastname: Fryirs
authors.affiliation: Pacific Spatial Solutions, Reston, VA, United States of America.
authors.forename: Hiroo
authors.initials: H
authors.lastname: Imaki
authors.affiliation: Department of Watershed Sciences, Utah State University, Logan, UT 84322-5210, United States of America.|Ecology Center, Utah State University, Logan, UT, 84322-5210, United States of America.
authors.forename: Martha
authors.initials: M
authors.lastname: Jensen
authors.affiliation: Department of Watershed Sciences, Utah State University, Logan, UT 84322-5210, United States of America.
authors.forename: Gary
authors.initials: G
authors.lastname: O'Brien
authors.affiliation: Wildland Hydrology, Fort Collins, CO, 80524, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Rosgen
authors.affiliation: Department of Watershed Sciences, Utah State University, Logan, UT 84322-5210, United States of America.|Ecology Center, Utah State University, Logan, UT, 84322-5210, United States of America.
authors.forename: Joseph
authors.initials: J
authors.lastname: Wheaton
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring; D055868:Floods; D025341:Principal Component Analysis; D012474:Salmon; D014481:United States; D014872:Water Movements