Urban Digital Twin
Urban digital twin is a compilation of 3D models including buildings, road infrastructure, street furniture and greenery that creates a comprehensive visual and simulative virtual model of the existing cityscape. The urban digital twin supports living lab activities in several ways: ideas can be tested, experimented with and demonstrated early with the digital twin. Data can also be collected with the twin and exported for various purposes, such as to support the development of new services. Capability for a quick and easily controllable 3D environment creates easily understandable tools for communicating plans, designs and ideas in the urban context.
Urban planning and construction professions are widely using 3D models as a basis for information management. Building information modeling software technologies provide means for managing and automating the handling of vast datasets and transforming them into easily understandable 3D forms. As there is a vast number of data and 3D model sources needed to model the urban environment, it is vital for an urban digital twin, that the underlying software can manage and process a wide range of data sources.
The development of the urban digital twin started in Kalasatama, the Helsinki Smart City District, in 2018, with the aim of producing high quality digital twin city models of the area and sharing the models as open data. The models serve as a platform for designing, testing, applying and servicing the entire lifecycle of the built environment. The effective use of urban digital twins is not only a technological question but it also means that workflows and decision making processes need to be reshaped.
In Kalasatama, digital twins were produced with the latest modelling technologies and applications as a CityGML standard-based semantic city information model and a reality mesh model. The City GML model contained future buildings (under construction and still in the planning phase), bridges, waterbody and terrain. It was made available also through the CityPlanner platform for the residents, who could explore the area and its features in 3D. The platform was also used for gathering resident feedback, as it could be used in creating questionnaires and gathering location-based information and answers to the 3D-model.
The urban digital twin supports living lab activities in several ways: ideas can be tested, experimented with and demonstrated early with the digital twin. Data can also be collected with the twin and exported for various purposes, such as to support the development of new services.
Fast data access through 5G networks, urban model updating through robotics and extended reality and virtual multi-user solutions provided by video game industry tools are integral parts of the urban digital twins of the future.
Urban digital twin of natural environment
During recent years, one of the focus areas for developing the digital twin of Kalasatama has been environmental modelling of urban areas in order to support the climate goals of the city. Creating an urban digital twin of the natural environment is, however, more complex than modelling things like buildings as nature changes throughout seasons and years. When modelling natural environments, the focus is therefore on growth patterns, weather simulations and qualities of different species instead of static objects.
Hermanninranta is a neighbourhood in northern Kalasatama that will provide housing and services for 5,000 residents. The area, located by the sea, contains a ruderate area that is prone to flooding. From the very beginning, the focus in urban planning has been on maximising green infrastructure in Hermanninranta and finding ways to integrate nature-based solutions into the plans. Developing an urban digital twin of the area supports these wider goals.
As part of the B.Green project, new green infrastructure and plant life models are experimented with and tested together with the more commonly used building and infrastructure 3D models in Hermanninranta. One of the aims is to integrate the use of urban digital twins into decision-making processes by, for example, showcasing future plans with visualisation tools from the video game industry which have great potential in modelling green infrastructure and visualising the direct and indirect ecosystem values it can produce on a larger scale. Dynamic 3D modelling also presents new possibilities for interaction and communication between professionals from different fields, as well as between experts and citizens. The B.Green project facilitates pilots and experiments in Kalasatama to utilise the urban digital twin for collecting and visualising hyperlocal environmental data as well as demonstrating future plans of the entire Kalasatama district for the residents in an easily understandable way.