7db04405-2f5e-4543-aa94-948ddbcd588a English ISO/IEC 8859-1 (also known as Latin 1) dataset dataset NERC EDS Environmental Information Data Centre Lancaster Environment Centre, Library Avenue, Bailrigg Lancaster LA1 4AP UK info@eidc.ac.uk https://eidc.ac.uk/ EIDC website The Environmental Information Data Centre (EIDC) is the UK's national data centre for terrestrial and freshwater sciences. information pointOfContact 2025-11-13T16:16:38 UK GEMINI 2.3 WGS 84 Numerical model simulations of channel flow for the South Saskatchewan River, Canada 2019-12-12 publication https://catalogue.ceh.ac.uk/id/7db04405-2f5e-4543-aa94-948ddbcd588a 10.5285/7db04405-2f5e-4543-aa94-948ddbcd588a doi: Ashworth, P., Nicholas, A., Parsons, D., Sambrook Smith, G., Unsworth, C. (2019). Numerical model simulations of channel flow for the South Saskatchewan River, Canada. NERC EDS Environmental Information Data Centre 10.5285/7db04405-2f5e-4543-aa94-948ddbcd588a Datasets consists of the results of Computational Fluid Dynamics (CFD) flow simulations for a section of the South Saskatchewan River, Canada. The aim of these CFD simulations was to investigate the effect of dunes on the depth-averaged and near-bed flow fields. Modelling was carried out using the open source CFD package OpenFOAM to solve the three-dimensional Navier-Stokes equations. The dataset consists of two files, one with simulation results for a river bed characterised by alluvial bedforms (dunes) and one for a smooth river bed without dunes. This work was part of NERC project NE/L00738X/1. Digital Surface Models (DSMs) were constructed using imagery obtained on four occasions (13th May 2015; 2nd Sept 2016; 8th June 2017; and 12th June 2017). Full details about this dataset can be found at https://doi.org/10.5285/7db04405-2f5e-4543-aa94-948ddbcd588a Ashworth, P. University of Brighton p.ashworth@brighton.ac.uk author Nicholas, A. Exeter University a.p.nicholas@exeter.ac.uk author Parsons, D. University of Hull d.parsons@hull.ac.uk author Sambrook Smith, G. University of Birmingham g.smith.4@bham.ac.uk https://orcid.org/0000-0002-3707-1182 ORCID record ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and a transparent method of linking research activities and outputs to these identifiers. information author Unsworth, C. Exeter University ChrisAUnsworth@outlook.com author Nicholas, A. Exeter University a.p.nicholas@exeter.ac.uk pointOfContact NERC EDS Environmental Information Data Centre info@eidc.ac.uk custodian NERC EDS Environmental Information Data Centre info@eidc.ac.uk publisher hydrologic flow GEMET - Concepts, version 4.1.3 2019-01-28 creation Hydrology otherRestrictions no limitations otherRestrictions © Natural Environment Research Council otherRestrictions This resource is available under the terms of the Open Government Licence otherRestrictions If you reuse this data, you should cite: Ashworth, P., Nicholas, A., Parsons, D., Sambrook Smith, G., Unsworth, C. (2019). Numerical model simulations of channel flow for the South Saskatchewan River, Canada. NERC EDS Environmental Information Data Centre https://doi.org/10.5285/7db04405-2f5e-4543-aa94-948ddbcd588a textTable 1000 English utf8 inlandWaters environment 2015-05-13 2017-06-17 -108.105 -103.831 53.43 56.029 Comma-separated values (CSV) NERC EDS Environmental Information Data Centre info@eidc.ac.uk distributor https://data-package.ceh.ac.uk/sd/7db04405-2f5e-4543-aa94-948ddbcd588a.zip Supporting information Supporting information available to assist in re-use of this dataset information https://data-package.ceh.ac.uk/data/7db04405-2f5e-4543-aa94-948ddbcd588a Download the data Download a copy of this data download dataset dataset Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 The aim of these CFD simulations was to investigate the effect of dunes on the depth-averaged and near-bed flow fields. To accomplish this, simulations were conducted using two meshes: one using high resolution measured channel morphology that included dunes, and one with the dune-scale morphology removed from the model domain. A digital elevation model (DEM) for the model domain was constructed from specially commissioned aerial imagery (pixel resolution 0.06 m) captured at a height of ~1500 m from a fixed-wing airplane with an UltraCamXp sensor. A 0.06 m resolution DEM was constructed using a combination of large format Structure-from-Motion (SfM) photogrammetry (using the commercial software Pix4D) and a regression model between water-depth and image brightness (see Strick et al., 2019). SfM techniques were applied to generate a DEM in emergent areas and in a narrow section along one channel bank where the river bed is composed predominantly of gravel. A depth-brightness model was applied in all other areas to calculate water depth from pixel brightness in the aerial imagery. The DEMs generated using SfM and the depth-brightness model were merged to produce a single DEM for use in CFD mesh generation. To remove dunes from the original 0.06 m resolution DEM constructed from aerial photography without affecting the representation of bank or bar topography, the outlines of the banks and bar fronts were identified visually in ARCMAP, and raster masks produced to separate each bar surface for individual filtering. River banks and the bar lee slopes of the unit bars were therefore not modified. To remove the dunes from the individual bar tops a moving-average, weighted-mean filter was used, with a window size of 6 m x 1 m, with the longest axis in the downstream direction, parallel to dune length. Two structured, finite volume CFD meshes were then constructed (one including dune morphology and one with dunes removed) for CFD modelling, both comprised of 4948 x 1172 x 20 cells in the downstream, cross-stream and vertical directions respectively. Horizontal mesh resolution was an average of 8 cm with 20 cells in the vertical and a planar water surface (at 0 m depth). Modelling was carried out using the open source CFD package OpenFOAM to solve the three-dimensional Navier-Stokes equations with a Re-Normalization Group (RNG) k-epsilon turbulence closure. The free surface was represented in the model with a rigid-lid approximation. Inlet conditions were defined using measured flow velocities. A Neumann pressure condition was set at the outlet. Second order central differencing numerical schemes were used for gradients, second order bounded central differencing for divergence; and an unbounded second order deferred corrected scheme for the Laplacian surface normal gradients were employed. Convergence criteria were iteratively tested and set to a tolerance of 1x10-8 for pressure and 1x10-10 for velocity, k and epsilon. Solver tolerances were set to 1x10-10 for pressure and 1x10-12 for velocity. The results of two simulations are included here.