Next Article in Journal
Comparison of the Performance of Two Advanced Spectral Methods for the Analysis of Times Series in Paleoceanography
Next Article in Special Issue
Coupled Wave Energy and Erosion Dynamics along a Salt Marsh Boundary, Hog Island Bay, Virginia, USA
Previous Article in Journal / Special Issue
Formulating Fine to Medium Sand Erosion for Suspended Sediment Transport Models
Article Menu

Export Article

Open AccessArticle
J. Mar. Sci. Eng. 2015, 3(3), 935-956;

The Influence of Bed Roughness on Turbulence: Cabras Lagoon, Sardinia, Italy

Ocean and Earth Sciences Department, National Oceanography Centre Southampton, Southampton SO14 3ZH, UK
MARUM Centre for Marine Environmental Sciences, University of Bremen, Bremen D-28334, Germany
Institute of Marine Science ISMAR, National Research Council, Lanusei (OG) 08045, Italy
Institute for coastal marine environment (IAMC), National Research Council, Oristano (IT) 09170, Italy
Author to whom correspondence should be addressed.
Academic Editor: Charitha Pattiaratchi
Received: 9 June 2015 / Accepted: 11 August 2015 / Published: 19 August 2015
(This article belongs to the Special Issue Sediment Transport Modeling)
Full-Text   |   PDF [6114 KB, uploaded 19 August 2015]   |  


Estimates of bed roughness used for predictions of sediment transport are usually derived either from simple scalars of the physical roughness (i.e., ripple height or grain size) or from the hydrodynamic roughness length (Zo) based upon velocity gradient estimates in the benthic boundary layer. Neither parameter accounts for irregular bed features. This study re-evaluates the relation between hydrodynamic roughness and physical bed roughness using high-resolution seabed scanning in the inlet of a shallow lagoon. The statistically-robust relationship, based on a 1D statistical analysis of the seabed elevation at different locations of the Cabras lagoon. Sardinia, has been obtained between Zo and the topographical bed roughness Ks by defining Ks = 2*STD + skin friction, with STD the standard deviation of the seabed elevation variations. This correlation between Ks and Zo demonstrates that the roughness length is directly influenced by irregular bed features, and that the Reynolds number accounts for the total drag of the bed: the data points collapse on the Law of the Wall curves with a fitting factor x = 0.5. Further testing must be done in other locations and in the fully-rough domain in order to test how widely those new parameters can be applied. View Full-Text
Keywords: turbulence; bed roughness; small-scale topography; roughness length; Law of the Wall turbulence; bed roughness; small-scale topography; roughness length; Law of the Wall

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Chirol, C.; Amos, C.L.; Kassem, H.; Lefebvre, A.; Umgiesser, G.; Cucco, A. The Influence of Bed Roughness on Turbulence: Cabras Lagoon, Sardinia, Italy. J. Mar. Sci. Eng. 2015, 3, 935-956.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
J. Mar. Sci. Eng. EISSN 2077-1312 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top