PhD: Seasonal processes (incl. freeze-thaw and ice cover impacts) within river systems, and development of their data analyses and observation methods, enabling their inclusion into digital twins of watersheds

Organisation

Aalto University

Description

More than half of Earth’s rivers are covered by ice during the winter months and their catchments cover more than one-third of the land area globally. In addition to changing seasonal river discharges, climate change is changing river ice regimes; shorter ice-cover duration is observed in many, and river ice cover will continue to decline over the 21st century on a global scale. This is critical, as river ice regulates, together with discharges, important functions of river systems, including river flow characteristics, flooding, and sediment transport, which in turn affect ecosystem functioning and biodiversity, and also impact human societies. Climate change is affecting the globe the fastest within the polar region, where the river environment functions within the watersheds are dependent on the seasonal hydrological conditions and the length of the ice-covered period. Therefore, for understanding these future impacts, present seasonal processes are needed to understand, data processing approaches and observation networks are needed to develop, and also inclusion of the processed observations to Digital Twins of watersheds, are crucial for enhancing the understanding of the changing river systems, and also larger societal impacts.

PhD project description

Previous studies demonstrated that the sediment load of Arctic rivers is controlled by the surface temperature of the watershed and its relief and that the greatest concentrations of sediment transport occur in spring during the main period of dynamic river ice break-up. However, recently it has been shown that in small sub-arctic Fennoscandian river channels, there is extensive sediment transport also in mid-winter. In addition to the unknowns in the ice formation, there are also large unknowns in the impact of ice on both flow characteristics and sediment transport.

The doctoral researcher will 1) first of all analyze these current seasonal fluvial processes and fills in the gaps in understanding their impact on flow, sediment transport, and channel processes. However, the main emphasis is on the 2) the development of novel data analysis methods, with the help of novel observation systems, for understanding these seasonal processes, and finally 3) further enabling the inclusion of this processed seasonal information to Digital Twins of watersheds, created in collaboration with the DIWA consortium.

Link to DIWA Research theme

RT1, RT2, RT3, RT4

Link to PhD pilot Key research area

1) Climate-hydrology, ecosystems, inflow forecasting

3) River systems, regulation and management

Specific requirements

The position requires a strong theoretical background in fluvial research. Spatial data processing, field measurement, and computational methods are considered as an asset. Thus, applicants should have a Masters’ degree in water and environmental engineering, hydrological sciences, environmental sciences, physical geography, or other relevant fields of science regarding fluvial research, spatial data analyses, and computational methods.

Secondment

Collaboration/secondment with the Finnish Environment Institute (Syke), Natural Resources Institute Finland (Luke), and Geological Survey of Finland (GTK), among others.