Freshwater Competence Centre is building a digital twin of a river by collecting and joining data piece by piece

This autumn two of the Freshwater Competence Centre partners University of Turku and Finnish Geospatial Research Institute FGI have been on a tour in Northern Finland collecting data for creating the basis for a digital twin – a full 3D model of the physical characteristics of a river, spiced up with some remote sensing, artificial intelligence and neat models for environmental management and decision-making purposes.?

Watch the video of the field work of this autumn season!

The work was carried out in three locations: at the river Oulanka next to the field station of University of Oulu, at Pulmanki river, that flows into the Tana river, as well as the Tana river itself. Actually, the work was carried out in three locations and three layers, because the scientists were measuring the same areas from up in the air in a helicopter, land based terrestrial laser scanners as well as an unmanned surface vehicle, that uses a multi-beam sonar to create a sharp 3D model of the riverbed underwater. What is more, as rivers do not mind the sovereign state borders, the work was carried out in two countries: Finland and Norway, reaching all the way to Barents Sea coast where Tana river flows in the sea.??

Not sure what a digital twin is? Read the article below:

“We took one flying day in Oulanka river and around the station and spent four days in Pulmanki and Teno area.” Harri Kaartinen from FGI tells. “This was the biggest data collection this far, using our new three-wavelength airborne laser scanning system. This was the first time we used this system for the catchment area mapping in such large scale.” The new system allows a seamless topography of the river valley, ranging from the riverbanks to the shallower sections of the underwater riverbed. Before this new sensor combination, building such a map required combining several different data sources. Particularly mapping the underwater areas with a sonar is very labor intensive and takes a long time. The sonar is also not as functional in the shallowest parts of the rivers. Therefore, the new laser scanning system collecting data with just one helicopter flight is a huge improvement.??

Read more about the laser scanning sensors of the FGI in the article below:

However, the new laser scanning system does have certain limitations: it cannot reach the deepest parts of the river. Therefore, University of Turku has been working in the same areas using their new unmanned surface vehicle, that scans the deepest sections with a multi-beam sonar. Data is also collected with terrestrial laser scanners as well as mobile laser scanning backpack, to complete and compare with the data from the helicopter scans.??

Doctoral candidate Linnea Bl?field, with her colleaques from University of Turku was collecting this data on the ground level. “Some of these meandering river areas have been studied since the 1970’s” she explains. “We are studying what are the processes that affect the meandering of the rivers – for example the water flow, the grain size of the riverbed, the stream gradient and other physical factors”. University of Turku scientists have been using for example Acoustic Doppler Current Profiler (ADCP), drone aerial imagery and terrestrial laser scanners for measuring the rivers above and below surface. “Now all of this could be done with the helicopter-based laser scanning system, much faster and sharper, but the data we have collected with the more traditional methods is useful for validating and calibrating the newer methods.”??

Bl?field’s PhD work is about the sediment connectivity in the Sub-Arctic areas. The phenomena familiar in Finland, such as melting of the snow, spring flooding and river ice breakup, are not considered in international indexes and built river models – such parameters simply do not exist yet, Bl?field explains. Her work is to define the parametrisation and build the indexes for such phenomena, so that the new digital twin built by the Freshwater Competence Centre can realistically predict the sediment transport in these sub-arctic environments. ?

?The areas that the scientists are working in are remote and sometimes difficult to access - what is the one item they would never leave behind when going to do work in such areas? “Battery charger”, answers Harri Kaartinen in a heartbeat. Sounds like he can state this with some actual real-life experience “Yep. For the cellphone, computer, and batteries for the sensors”. Linnea Bl?field sounds more hesitant. “A Leatherman, I think.” What would you use the Leatherman for in the field? “Well, it’s just handy to have it, for cutting zip ties and quick fixing of things”.??

Hold on… Is your research equipment put together with zip ties? “No... But they are used for all kinds of things, for example this time we lost the kill switch for the dinghy engine, and that was replaced with a zip tie.”?

The conclusion seems to be that bringing the right chargers, a Leatherman and a few zip ties is a clever idea!?

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Text by Annukka Pekkarinen, Napaja.org