Description: 

In high-latitude and high-altitude rivers, winter ice cover and its break-up can have a large impact on bank erosion and sediment transport. Climate change will affect the ice regime by decreasing the duration of ice cover, altering the number of 0° C-crossings and thus ice break-up events, and change the timing of ice break-up/cover in relation to high flows. In order to understand how climate change will affect ice-related bank erosion and sediment transport, continuous monitoring of sub-ice sediment transport and concurrent with ice break-up is needed to compare with erosion and sediment transport processes due to high flows with and without ice-covered streambanks. Measurement of sediment transport and bank erosion under ice or during ice-breakup has previously been nearly impossible due to practical methodological problems and safety concerns during field work. Preliminary studies have proven that environmental seismology techniques can quantify sub-ice sediment transport as well as during ice break-up.

In this project, we will use environmental seismology to quantify the role of ice on sediment transport in different river ice regimes. Seismic networks will be installed along several rivers spanning a climatic gradient in northern Sweden (60- 68° N) to calibrate the seismic signature of various ice-related processes with field measurements of sub-ice and open-channel sediment transport and bank erosion. The timing of sediment transport in relation to river ice proceses will be used to determine the role of different ice regimes on shaping river channels. The project may also involve hydraulic models to predict changes in the ice regime in a warmer climate and how this will affect streambank erosion and sediment transport. 

Link to apply (deadline: 22/12/2022): https://www.umu.se/en/work-with-us/open-positions/phd-position-in-physical-geography-with-a-focus-on-fluvial-geomorphology-environmental-seismology-and-river-ice-dynamics_565389/

Keywords: rivers, river ice, sediment transport, bank erosion, climate change, field work

Host institute: Umeå University, Sweden

Supervisors: Lina Polvi Sjöberg (Umeå University, Sweden)

Co-supervisor: Florent Gimbert (Université Grenoble Alpes, France)

Collaborations: During the project, collaborations are envisaged with the County Administrative Board in Västerbotten which manages and restores rivers, and other institutions participating in the EnvSeis project dealing with river sediment transport.