Numerical Modeling Of Flow And Sediment Transport Within The Lower Reaches Of The Athabasca River: A Case Study

• Main Authors: Kashyap, Shalini, Shakibaei, Ahmad, Oveisy, Ali, Dibike, Yonas, Prowse, Terry, Ian, Droppo
• Format: Conference Object
• Language: English
• Published: CUNY Academic Works 2014
• Subjects: 2014 International Conference on Hydroinformatics HIC; Hydrodynamic Modelling; numerical modeling; Sediment transport; cohesive sediment; river erosion; bathymetry survey; R13; Sediment Transport Modeling; Environmental Sciences; Physical Sciences and Mathematics; Water Resource Management; Athabasca River; Canada; Steepbank River
• Online Access: https://academicworks.cuny.edu/cc_conf_hic/112; https://academicworks.cuny.edu/cgi/viewcontent.cgi?article=1111&context=cc_conf_hic

This study investigates flow and sediment transport patterns within the lower reaches of the Athabasca River (~250 km) in Alberta, Canada, which are characterized by complex bathymetry, regions of high tortuosity, and variable discharges and bed slopes. Sediment within this reach is primarily sand and gravel, but there is also a high percentage (>10%) of cohesive clay with unique settling properties. A combination of 1D and 2D regional numerical modeling is used here to predict hydrodynamics of the flow and transport of suspended sediment. Bathymetry measurements were obtained from a combination of high resolution 3D Geoswath and ADCP surveys, and detailed 2D cross-section measurements. The 1D model solves the advection-diffusion equation for the cohesive sediment floc concentrations, and uses an explicit flocculation algorithm to calculate their distribution. Regional and high resolution local 2D numerical simulations are also completed using the Environmental Fluids Dynamics Code (EFDC) for the entire reach and a reach near Steepbank River (<20 km) respectively. The high resolution local model helps in understanding the effects of coarse grid resolution and subsequently bathymetry resolution on the predictions. Validation of the model results is completed using field measurements including water surface elevations collected with Global Positioning System (GPS), water velocities collected using a Gurley current meter, and suspended sediment measurements obtained from the Regional Aquatics Monitoring Program.