Sensitivity of interfacial hydraulics to the microtopographic roughness of water-lain gravels

Auteur(s) et Affiliation(s)



Description :
The AA.hypothesized that different gravel-bed microtopographies generate measurable differences in hydraulic characteristics within the interfacial layer. This was tested using a high density of spatially and vertically distributed, velocity time series measured in the interfacial layers above 3 surfaces of contrasting microtopography. Analysis was repeated for 3 discharges to evaluate whether discharge affected the impact of microtopography on interfacial flows. Between-surface differences in the median and variance of several time-averaged and turbulent flow parameters were tested using non-parametric statistics. It is highlighted that observable differences in microtopography do not necessarily produce differences in interfacial hydraulics. An important observation is that appropriate roughness parameterizations for gravel-bed rivers remain elusive, partly because the relative contributions to flow resistance of different aspects of bed microtopography are poorly constrained.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2014, vol. 39, n°. 2, p. 184-199, nombre de pages : 16, Références bibliographiques : 2 p.

Date :
2014

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley