IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 34th Congress - Brisbane (2011) : THEME 5: Environmental Hydraulics and Hydrology : Determining resistance coefficients for ice-covered rivers from observed velocity profiles
Determining resistance coefficients for ice-covered rivers from observed velocity profiles
Author : A. Hoque1 and S.S. Li1
The purpose of this paper is to evaluate flow resistance exerted by the ice cover in shallow sub-arctic rivers. From observed velocity profiles, the Manning’s roughness coefficients associated with the ice cover are calculated using four different methods. The methods are based on, respectively, observed depth-averaged and maximum flow velocities, logarithmic velocity distributions fitted to the profiles, energy slope in addition to the fitted velocity distributions, and the Manning’s flow resistance equation. The applicability of the methods is examined by comparing the calculated roughness coefficients. The roughness coefficients range from 0.01 to 0.02 for the wide, shallow river channels. These values reflect the average resistance condition over the winter. The roughness coefficients can increase month by month up to six-fold. The method using depth-averaged and maximum flow velocities directly does not give satisfactory results for shallow river channels, whereas the method based on fitted logarithmic velocity distributions has shown advantages.
File Size : 486,575 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 34th Congress - Brisbane (2011)
Article : THEME 5: Environmental Hydraulics and Hydrology
Date Published : 01/07/2011
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