A new model to analyse the impact of woody riparian vegetation on the geotechnical stability of riverbanks

Marco J. Van de Wiel, Stephen E. Darby

Research output: Contribution to journalArticlepeer-review

61 Citations (Scopus)


We present a geotechnical stability analysis for the planar failure of riverbanks, which incorporates the effects of root reinforcement and surcharge for mature stands of woody riparian vegetation. The analysis relies on a new method of representing the root distribution in the soil, which evaluates the effects of the vegetation's position on the bank. The model is used in a series of sensitivity analyses performed for a wide range of bank morphological (bank slope and height) and sedimentological (bank cohesion and friction angle) conditions, enabling discrimination of the types of bank environment for which vegetation has an effect on bank stability. The results indicate that woody vegetation elements have a maximal impact on bank stability when they are located at the ends of the incipient failure plane (i.e. at the bank toe or at the intersection of the failure plane with the floodplain) and that vegetation has a greater effect on net bank stability when it is growing on low, shallow, banks comprised of weakly cohesive sediments. However, the magnitude of these effects is limited, with vegetation typically inducing changes (relative to non-vegetated banks) in simulated factors of safety of less than 5%. If correct, this suggests that the well documented effects of vegetation on channel morphology must be related to alternative process mechanisms (such as the interaction of vegetation with river flows) rather than the mechanical effects of vegetation on bank failure, except in special cases where the equivalent non-vegetated bank has a highly marginal stability status.

Original languageEnglish
Pages (from-to)2185-2198
Number of pages14
JournalEarth Surface Processes and Landforms
Issue number14
Early online date2 May 2007
Publication statusPublished - Dec 2007
Externally publishedYes


  • Bank erosion
  • Geotechnical
  • Root reinforcement
  • Stability analysis
  • Vegetation

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)
  • Earth-Surface Processes
  • Geography, Planning and Development


Dive into the research topics of 'A new model to analyse the impact of woody riparian vegetation on the geotechnical stability of riverbanks'. Together they form a unique fingerprint.

Cite this