The urban building process, including environmental analysis, has great potential for efficiency and benefit increase through digitization and smart information management. 3D city models are used in many places for visualization, but these are usually lacking connection to most municipality information systems. A smart 3D city model, in which all objects contain a large amount of interconnected information, is called a digital twin of the city and, in addition to visualizations, also facilitates analyses and simulations; these analysis and simulations provide a valuable decision basis for urban planning and investment in the city.

In this project we will study how a digital twin can be used for heavy rain modelling, which is an increasingly important analysis in time of climate change. To model the movement of the water and its consequences both indoor and outdoor information is required, which can form a part of a digital twin. In order to realize a digital twin, an underlying information model is required that allows the information to be connected in a smart way. This project aims to develop such an information model, based on CityGML and Swedish national specifications. As a basis, there are previous national studies on how buildings should be managed in a Swedish profile of CityGML; these studies will here be extended to more themes, e.g. roads and land use.

The project will also evaluate the implementation of the information model in a database structure as well as visualize it and use it for heavy rain modelling. Furthermore, the project will develop processes for how the municipality can sustainably update and version the smart 3D city model, i.e. the digital twin. The intention is that the project result should be applicable to all municipalities in Sweden who intends to build a digital twin based on open standards.

Project leader: Maria Uggla, Stockholms stad