000212998 001__ 212998
000212998 005__ 20190317000312.0
000212998 037__ $$aCONF
000212998 245__ $$aHydro-morphodynamic differences induced by different angles in an experimental discordant confluence
000212998 269__ $$a2015
000212998 260__ $$c2015
000212998 336__ $$aConference Papers
000212998 500__ $$a[1039]
000212998 520__ $$aConfluences, within the fluvial network, are considered particular areas with great ecological value, where flow dynamics and bed morphology are complex and highly three-dimensional. Several parameters influence the morphodynamics and hydrodynamics of river confluences including discharge and momentum ratios, angle of confluence and sediment transport. Confluences with low discharge and momentum ratios, where narrow steep tributaries with high sediment load join a wide low-gradient main-channel that provides the dominant discharge, are often observed in the Upper-Rhone river in Switzerland. Few existing studies have looked at the hydro-morphodynamics of this type of river confluences considering sediment discharge in both confluent channels. This paper aims to analyze the influence of the confluence angle on the flow dynamics and bed morphology of this type of confluences in an experimental facility under movable bed conditions. For that purpose, two experiments were carried out in a laboratory confluence with low discharge and momentum ratios (Qr = 0.11 and Mr = 0.16 respectively), and with two different confluence angles (α = 90° and 70°). During the experiments, two distinct poorly shorted sediment mixtures were supplied into the tributary and into the main channel at constant but different rates for each flume. The experiments were run until equilibrium in bed morphology was reached. During the experiments bed topography surveys were systematically recorded, and water surface was measured at equilibrium. These measures illustrate the bed topography evolution during the experiments, and the confluence hydrodynamics at equilibrium. The results show that different confluence angles resulted in different flow regimes and bed elevations in the tributary. Also, the distinct angle configurations yielded different water surface elevations in the main channel upstream of the confluence.
000212998 6531_ $$ariver confluences
000212998 6531_ $$aconfluence angle
000212998 6531_ $$adiscordant bed
000212998 6531_ $$asediment transport
000212998 6531_ $$asupercritical flow
000212998 700__ $$g210089$$aGuillén Ludeña, Sebastián$$0245626
000212998 7112_ $$dJune 19- July 3, 2015$$cThe Hague, The Netherlands$$aIAHR 2015
000212998 773__ $$jon-line version$$tProc. of Int. Congress IAHR 2015
000212998 8564_ $$uhttps://infoscience.epfl.ch/record/212998/files/2015-1039_Guill%C3%A9n_Hydro-morphodynamic%20differences%20induced%20by%20different%20angles%20in%20an%20experimental%20discordant%20confluence.pdf$$zn/a$$s725143$$yn/a
000212998 909C0 $$xU10263$$0252079$$pLCH
000212998 909C0 $$pPL-LCH$$xU10263$$0255473
000212998 909CO $$qGLOBAL_SET$$pconf$$pENAC$$ooai:infoscience.tind.io:212998
000212998 917Z8 $$x246105
000212998 937__ $$aEPFL-CONF-212998
000212998 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000212998 980__ $$aCONF