Author(s): Alexandre Hauet; Thomas Morlot; Lea Daubagnan

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Keywords: No Keywords

Abstract: For measuring flood discharge with non-intrusive methods, one should know the depth-averaged to surface velocity ratioα. In this paper, a large sample of gauging (3611 gaugings over 176 sites of EDF-DTG) realized with a current meter are analyzed to computeαwith three methods: fitting of a log-and a power-law and using the measured surface velocity. Results show that the three methods give very similar results, with a mean value ofαof about 0.8, with few dispersion (5th and 95th percentile values being about 0.7 and 0.9). A link betweenαand the water depth is established, asαincreases with the hydraulic radius. The link betweenαand the bed roughness, or betweenαand the relative roughness (Rh/d50) is not clear. Results only shows that the mean value ofαis 0.8 for natural rivers (sandy, pebbly or boulders rivers), and 0.9 for artificial concrete channels.

DOI: https://doi.org/10.1051/e3sconf/20184006015

Year: 2018