Velocity distribution in the roughness layer of rough-bed flows

V.I. Nikora, K. Koll, Ian Kenneth McEwan, S. R. Mclean, A. Ditrich

Research output: Contribution to journalArticlepeer-review

135 Citations (Scopus)


Several models for the vertical distribution of the double-averaged (in time and in the plane parallel to the mean bed) longitudinal velocity in the flow region between roughness troughs and roughness tops are suggested. We found that the same model for velocity distribution may be applicable to a range of flow conditions and roughness types, which share some common features. The suggested models for velocity distribution in the near-bed region are: (1) Constant velocity; (2) exponential velocity distribution; and (3) linear velocity distribution. The measured velocity distributions may be approximated by a single model or by a combination of models depending on roughness geometry and flow conditions. The validity of these models for velocity distribution is supported by laboratory data.

Original languageEnglish
Pages (from-to)1036-1042
Number of pages7
JournalJournal of Hydraulic Engineering
Issue number10
Publication statusPublished - 2004


  • open channel flow
  • turbulent flow
  • velocity distribution
  • roughness
  • channel beds
  • spatially averaged flow
  • open-channel flow
  • vegetation canopies
  • plant canopies
  • turbulence
  • model


Dive into the research topics of 'Velocity distribution in the roughness layer of rough-bed flows'. Together they form a unique fingerprint.

Cite this