The potential of 3D city models in managing comlexity in cities.

The inspiration to undertake this research topic was the participation of the initiator of  research B. Stelmach-Fita in the "Smart City Digital Twin Workshops" organized on September 8, 2023 in Gdańsk, Poland, and November 2, 2023 in Turku, Finland, by the University of Turku and Turku Business Region in Finland, popularizing this topic and area. Project researcher Tolga Karayel from the University of Turku and Professor Paweł Bartoszczuk from the Warsaw School of Economics, as well as Michał Michałowski, co-author of the 3D Model in Poznań, were invited to joint publication. For the created 3D model of the city, as well as its digital twin, the key aspect is the integration of various types of geospatial data. Current technologies additionally enable automated processes and analyzes using artificial intelligence (AI) and machine learning. The recipients of this type of solutions may be cities and other local government units, ports, national parks, as well as other entities obtaining or using spatial data.The aim of the research is to answer the question: what are the methods of creating 3D city models? What is the role of standards in this process? Can 3D city models and digital twins be helpful for liveable and resilient cities ? Moreover, the aim of the paper is to assess the possibilities of using 3D city models on the example of selected cities in Poland and the Nordic countries and to recommend good practices. Research methods include: participant observation (workshops, webinars organized by the University of Turku), interviews, questionnaire for selected cities. The research results indicate that the analyzed 3D city models meet the standards for their creation, including based on City GML, are constantly updated and developed, and what important made available to other users. In each of these cities, 3D models are characterized by different levels of detail. 3D models of cities support spatial planning, social participation and have great potential in managing the complexity of the city and building their resilience. The conclusions from research can provide guidance for methods of creating 3D city models to make cities more friendly to live in. However, the authors of the research do not overestimate the technologies described, treating them as a helpful tool in city management and, like other researchers, believe that decision-making in and for cities should be guided by common sense and not by technological progress. Future thinking for cities should focus not on developing smart cities, but on creating wise cities. There are many ways to create them, including using university resources and exchanging opinions and research results. An increasing number of scientists from various fields of scientific disciplines now appreciate active cooperation with the city as a great way to deepen knowledge and understanding, invent new theories while contributing to a public goal.