Eight. Instream Geomorphic Units

  1. Kirstie A. Fryirs1 and
  2. Gary J. Brierley2

Published Online: 28 SEP 2012

DOI: 10.1002/9781118305454.ch8

Geomorphic Analysis of River Systems: An Approach to Reading the Landscape

Geomorphic Analysis of River Systems: An Approach to Reading the Landscape

How to Cite

Fryirs, K. A. and Brierley, G. J. (2012) Instream Geomorphic Units, in Geomorphic Analysis of River Systems: An Approach to Reading the Landscape, John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9781118305454.ch8

Author Information

  1. 1

    Department of Environment and Geography, Macquarie University, North Ryde, NSW 2109, Australia

  2. 2

    School of Environment, University of Auckland, Auckland, New Zealand

Publication History

  1. Published Online: 28 SEP 2012
  2. Published Print: 16 NOV 2012

ISBN Information

Print ISBN: 9781405192750

Online ISBN: 9781118305454

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Keywords:

  • bank-attached geomorphic units;
  • compound instream geomorphic units;
  • erosional geomorphic units;
  • fine-grained sculpted geomorphic units;
  • forced instream geomorphic units;
  • instream geomorphic units;
  • mid-channel geomorphic units;
  • river systems

Summary

Geomorphic units are the building blocks of river systems. This chapter focuses on the process-form associations that generate and rework instream geomorphic units. Instream geomorphic units are found along a slope-induced energy and textural gradient. A continuum of features extends from high-energy erosional (sculpted) forms in bedrock and boulder settings to mid-channel depositional units and bank-attached forms. Forced units are produced when flow patterns and available energy are disrupted by obstructions such as bedrock, vegetation or wood that induce irregularities along the valley floor, thereby creating resistance. Sculpted forms may also be formed in low-energy, fine-grained settings. Unit features are products of single depositional events, whereas compound features reflect a range of flow conditions and reworking events. Inevitably, the pattern of features is intimately tied to channel geometry (shape and size).