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dc.contributor.authorWilliams, R. D.
dc.contributor.authorBrasington, J.
dc.contributor.authorHicks, M.
dc.contributor.authorMeasures, R.
dc.contributor.authorRennie, C. D.
dc.contributor.authorVericat Querol, Damià
dc.date.accessioned2018-11-26T09:12:32Z
dc.date.available2018-11-26T09:12:32Z
dc.date.issued2013
dc.identifier.issn0043-1397
dc.identifier.urihttp://hdl.handle.net/10459.1/65187
dc.description.abstractGravel‐bed braided rivers are characterized by shallow, branching flow across low relief, complex, and mobile bed topography. These conditions present a major challenge for the application of higher dimensional hydraulic models, the predictions of which are nevertheless vital to inform flood risk and ecosystem management. This paper demonstrates how high‐resolution topographic survey and hydraulic monitoring at a density commensurate with model discretization can be used to advance hydrodynamic simulations in braided rivers. Specifically, we detail applications of the shallow water model, Delft3d, to the Rees River, New Zealand, at two nested scales: a 300 m braid bar unit and a 2.5 km reach. In each case, terrestrial laser scanning was used to parameterize the topographic boundary condition at hitherto unprecedented resolution and accuracy. Dense observations of depth and velocity acquired from a mobile acoustic Doppler current profiler (aDcp), along with low‐altitude aerial photography, were then used to create a data‐rich framework for model calibration and testing at a range of discharges. Calibration focused on the estimation of spatially uniform roughness and horizontal eddy viscosity, νH, through comparison of predictions with distributed hydraulic data. Results revealed strong sensitivity to νH, which influenced cross‐channel velocity and localization of high shear zones. The high‐resolution bed topography partially accounts for form resistance, and the recovered roughness was found to scale by 1.2–1.4 D84 grain diameter. Model performance was good for a range of flows, with minimal bias and tight error distributions, suggesting that acceptable predictions can be achieved with spatially uniform roughness and νH.ca_ES
dc.description.sponsorshipField campaigns were primarily funded by NERC Grant NE/G005427/1 and NERC Geophysical Equipment Facility Loan 892 as well as NSERC and CFI (Canada) grants to Colin Rennie. Damia Vericat was supported by a Ramon y Cajal Fellowship (RYC‐2010‐06264) funded by the Spanish Ministry of Science and Innovation during the preparation of this manuscript. Numerical simulations were undertaken during a visit by Richard Williams to NIWA. This visit was funded by the British Hydrology Society and an Aberystwyth University Postgraduate Studentship. Murray Hicks and Richard Measures were funded by NIWA core funding under the Sustainable Water Allocation Programme.ca_ES
dc.language.isoengca_ES
dc.publisherAmerican Geophysical Unionca_ES
dc.relation.isformatofReproducció del document publicat a https://doi.org/10.1002/wrcr.20391ca_ES
dc.relation.ispartofWater Resources Research, 2013, vol. 49, núm. 9, p. 5183-5205ca_ES
dc.rights(c) American Geophysical Union, 2013ca_ES
dc.titleHydraulic validation of two‐dimensional simulations of braided river flow with spatially continuous aDcp dataca_ES
dc.typeinfo:eu-repo/semantics/articleca_ES
dc.identifier.idgrec020409
dc.type.versioninfo:eu-repo/semantics/publishedVersionca_ES
dc.rights.accessRightsinfo:eu-repo/semantics/openAccessca_ES
dc.identifier.doihttps://doi.org/10.1002/wrcr.20391


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