Université de Sherbrooke and Concordia University are seeking a PhD candidate in River Engineering / Fluvial Geomorphology
Project title: Characterisation and prediction of fluvial bank retreat and planform change using novel physical and numerical experiments
Context: Riverbank erosion is a natural process, but rates are likely to increase with climate change due to several factors. Variable discharge regimes will affect frequency and intensity of fluvial erosion and changes in river grade causing incision and/or aggradation. It is thus important to further our fundamental knowledge of fluvial bank erosion to be better prepared for possible changes in erosion rates in future climate, for example in the design of bank protection structures (e.g., riprap, large wood). Various management scenarios, particularly those that include large wood configurations, need to be tested to enhance resilience of fluvial systems to the expected increase in discharge variability in the next decades.
Research Objectives: The main objective of this project is to provide a comprehensive description of fluvial bank erosion in meandering channels and assess the effects of different bank stabilization structures. This will be achieved through a series of controlled experiments conducted in a newly built, large-scale Outdoor Experimental River Facility (OERF) at Université de Sherbrooke (UdeS). Specifically, the project will assess the impact of different bank stabilization treatments (large wood and riprap) on flow structure and bank erosion using drone enabled structure-from-motion (UAV-SfM), large-scale particle image velocimetry (LSPIV) and acoustic Doppler velocimeters (ADV).
Methodology: The OERF is located on campus and will be used for the project’s physical experiments. This infrastructure is unique in Canada and is designed for the study of large-scale open-channel flow experiments (with a maximum flow of 0.8 m3/s) with sediment transport. The OERF consists of a dynamic river channel 50 m long and 3 m wide which can meander freely in a 20 m wide ‘valley’ corridor. The corridor is filled with rounded sediments (D50 = 10 mm).
Erosion experiments will be conducted at a range of flows up to bankfull. Morphological changes will be measured via UAV-SfM analysis with multiple passes in order to quantify the dynamics of the system. Continuous sediment transport measurements (bedload) will be undertaken using sediment traps distributed over the channel length. Near-bank flow structure (velocities, turbulence intensity, shear stress) will be characterised using the UAV data and LSPIV, as well as, velocity profiles obtained with an ADV. The above measurements will be conducted on unprotected and treated banks (e.g., riprap, large wood) to give a global understanding of the impact of bank stabilization structures on bank erosion processes. Time permitting, the velocity and bank erosion data obtained from the OERF experiments will be used to calibrate, validate and improve numerical morpodynamic models.
-A Master’s degree in a relevant subject: river engineering, fluid mechanics, fluvial geomorphology
-Experience in laboratory experimentation with sediment transport and advanced measurement techniques such as ADV and/or PIV
-Peer-reviewed scientific publications.
-Opened to Canadian citizens, Permanent Residents, as well as international applicants.
Institution: The workplace is at the Faculty of Engineering and OERF at the Université de Sherbrooke. The PhD student will work with other students and a multidisciplinary team of researchers working on the project: J. Lacey (UdeS), M. Trudel (UdeS), P. Biron (Concordia). The team brings together expertise in river engineering and fluvial geomorphology including sediment transport and bank erosion, physical and numerical experimentation, fluid dynamics, aerial imagery and treatment. A stipend of $20,000 CAD/year and excellent working conditions are offered (opportunities to attend conferences, professional development, etc). Starting date: May 1st 2021. Interested candidates are encouraged to contact by email: Prof Jay Lacey (Jay.Lacey@USherbrooke.ca). Send detailed CV, 3 recommendation letters (see Faculty format*) and copies of any relevant journal publications. French fluency is not necessary but is (or the desire to learn) an asset for working and living in a francophone environment.