Rivers in Finland are studied using especially accurate equipment – this helps prepare for extreme weather

The watercourses of the northern regions are heavily affected by the changing climate. As extreme weather increases, more accurate data on waterbodies are required.

Researchers have conducted measurements using unique mobile research equipment in the rivers Vantaanjoki, Oulankajoki and Tana, as well as its tributary Pulmankijoki. This is one of the first times in the world when data on rivers and their catchment areas have been produced at this level of accuracy.

The measurements have been conducted by the Finnish Geospatial Research Institute (FGI) of the National Land Survey (NLS), the University of Turku, Aalto University, the Finnish Environment Institute and the University of Oulu.

'River environments are affected by the changing climate. An accurate three-dimensional model of the riverbed and any changes in it helps understand how floods and the changing snow and ice conditions shape aquatic environments, and what kinds of risks this may pose to both the unbuilt and built environment,' says Research Professor Harri Kaartinen from FGI.

In the measurements, an elevation model covering the riverbed and catchment area is prepared to help detect erosion and changes after a flood, for example. The movement of sediments, the speed and direction of the water flow, and changes in the riverbed are also measured. Research data can be used to predict the behaviour of rivers in extreme situations, including unexpected heavy rainfall.

Researchers have access to new mobile equipment, such as a robotic boat, an underwater drone and laser scanners designed for underwater imaging. Laser scanners are also used in the air attached to drones, and the dense laser pulse they emit allows the surface contours of the ground and riverbed to be modelled accurately. Many of the devices have been customised for the research of aquatic environments and provide data that have not been previously available. 

The warming climate can be seen in waterbodies

Changes in waterbodies can already be seen. They suggest that climate change has a particularly significant impact on the northern regions.

'Spring arrives in Oulanka two weeks earlier, and the mean annual temperature has risen by three degrees during the last 50 years. Due to mild winters with little snow, spring floods take place earlier and are less powerful. In contrast, there are more floods during other seasons as a result of increased rainfall which has an impact, for example, on the transfer of nutrients and pollutants with water,' says researcher Linnea Blåfield from the University of Turku.

New research data help build a digital twin to model all the factors that affect waterbodies and all the ongoing changes. The goal of the study is to guide human activities and decision making processes to better prepare for extreme weather.

The Digital Waters (DIWA) flagship, funded by the Academy of Finland, enables a green and digital transition to generate digital twins of waterbodies. The cooperation project involves the University of Oulu, the University of Turku, Aalto University, the Finnish Environment Institute, FGI and the Finnish Meteorological Institute, as well as a large network of Finnish water sector organisations. Research is also conducted by the Freshwater Competence Centre funded by the Academy of Finland and the NextGenerationEU RRF programme, as well as the Green-Digi-Basin and Hydro-RI-Platform projects.

Further information

• Harri Kaartinen, Research Professor, Finnish Geospatial Research Institute of the National Land Survey of Finland, +358 29 531 4756, [email protected] (laser scanners)
• Linnea Blåfield, Doctoral Researcher, University of Turku, +358 50 540 0912, [email protected]  (impact of climate change on rivers Oulankajoki and Pulmankijoki)
• Petteri Alho, Professor, University of Turku, +358 29 450 2115, [email protected] (robotic boat)
• Eliisa Lotsari, Assistant Professor, Aalto University, +358 50 473 2282, [email protected] (underwater drone, river ice cover)

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